82_FR_50706 82 FR 50496 - Special Conditions: The Boeing Company Model 777-8 and 777-9 Airplanes; Interaction of Systems and Structures

82 FR 50496 - Special Conditions: The Boeing Company Model 777-8 and 777-9 Airplanes; Interaction of Systems and Structures

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 82, Issue 210 (November 1, 2017)

Page Range50496-50500
FR Document2017-23699

These special conditions are issued for The Boeing Company (Boeing) Model 777-8 and 777-9 airplanes. These airplanes will have novel or unusual design features when compared to the state of technology envisioned in the airworthiness standards for transport- category airplanes. These design features include systems that, directly or as a result of failure or malfunction, affect airplane structural performance. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for these design features. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

Federal Register, Volume 82 Issue 210 (Wednesday, November 1, 2017)
[Federal Register Volume 82, Number 210 (Wednesday, November 1, 2017)]
[Rules and Regulations]
[Pages 50496-50500]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-23699]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2017-0717; Special Conditions No. 25-704-SC]


Special Conditions: The Boeing Company Model 777-8 and 777-9 
Airplanes; Interaction of Systems and Structures

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for The Boeing Company 
(Boeing) Model 777-8 and 777-9 airplanes. These airplanes will have 
novel or unusual design features when compared to the state of 
technology envisioned in the airworthiness standards for transport-
category airplanes. These design features include systems that, 
directly or as a result of failure or malfunction, affect airplane 
structural performance. The applicable airworthiness regulations do not 
contain adequate or appropriate safety standards for these design 
features. These special conditions contain the additional safety 
standards that the Administrator considers necessary to establish a 
level of safety equivalent to that established by the existing 
airworthiness standards.

DATES: This action is effective on Boeing on November 1, 2017. We must 
receive your comments by December 18, 2017.

ADDRESSES: Send comments identified by docket number FAA-2017-0717 
using any of the following methods:
     Federal eRegulations Portal: Go to http://www.regulations.gov/and follow the online instructions for sending your 
comments electronically.
     Mail: Send comments to Docket Operations, M-30, U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery or Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
     Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: The FAA will post all comments it receives, without 
change, to http://www.regulations.gov/, including any personal 
information the commenter provides. Using the search function of the 
docket Web site, anyone can find and read the electronic form of all 
comments received into any FAA docket, including the name of the 
individual sending the comment (or signing the comment for an 
association, business, labor union, etc.). DOT's complete Privacy Act 
Statement can be found in the Federal Register published on April 11, 
2000 (65 FR 19477-19478).
    Docket: Background documents or comments received may be read at 
http://www.regulations.gov/ at any time. Follow the online instructions 
for accessing the docket or go to Docket Operations in Room W12-140 of 
the West Building Ground Floor at 1200 New Jersey Avenue SE., 
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Mark Freisthler, FAA, Airframe and

[[Page 50497]]

Cabin Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-1119; facsimile 425-227-1320.

SUPPLEMENTARY INFORMATION: The substance of these special conditions 
has been subject to the public-comment process in several prior 
instances with no substantive comments received. The FAA therefore 
finds it unnecessary to delay the effective date and that good cause 
exists for making these special conditions effective upon publication 
in the Federal Register.

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data.
    We will consider all comments we receive by the closing date for 
comments. We may change these special conditions based on the comments 
we receive.

Background

    On April 19, 2017 (for the Model 777-8 airplane), and May 12, 2015 
(for the 777-9 airplane), Boeing applied for an amendment to Type 
Certificate (TC) No. T00001SE to include the new Model 777-8 and 777-9 
airplanes. These airplanes are derivatives of the Model 777-300ER 
airplane currently approved under TC No. T00001SE. The Model 777-9 
airplane is a stretched-fuselage, large, twin-engine airplane with 
seating for 408 passengers and a maximum takeoff weight of 775,000 
pounds.
    The Model 777-8 airplane, a shortened-body derivative of the Model 
777-9 airplane, is a large, twin-engine airplane with seating for 359 
passengers and a maximum takeoff weight of 775,000 pounds.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, Boeing must show that the Model 777-8 and 777-9 airplanes 
meet the applicable provisions of the regulations listed in TC No. 
T00001SE, or the applicable regulations in effect on the date of 
application for the change, except for earlier amendments as agreed 
upon by the FAA.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Model 777-8 and 777-9 airplanes 
because of a novel or unusual design feature, special conditions are 
prescribed under the provisions of Sec.  21.16.
    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same novel or 
unusual design features, or should any other model already included on 
the same type certificate be modified to incorporate the same novel or 
unusual design feature, these special conditions would also apply to 
the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model 777-8 and 777-9 airplanes must comply with the 
fuel-vent and exhaust-emission requirements of 14 CFR part 34, and the 
noise-certification requirements of 14 CFR part 36.
    The FAA issues special conditions, as defined in 14 CFR 11.19, in 
accordance with Sec.  11.38, and they become part of the type 
certification basis under Sec.  21.101.

Novel or Unusual Design Features

    The Model 777-8 and 777-9 airplanes will incorporate the following 
novel or unusual design features:
    These Boeing airplanes have full-time, digital, electronic flight-
control systems (EFCS) affecting the pitch, yaw, and roll axes of the 
airplanes. In addition, the airplanes are equipped with on-ground load-
alleviation systems to reduce braking loads. The current regulations 
are inadequate for considering the effects of these systems and their 
effects upon structural performance. These special conditions define 
the criteria to be used in the assessment of the effects of these 
systems on structures.
    The general approach of accounting for the effect of system 
failures on structural performance would be extended to include any 
partial or complete system failure, alone or in combination with other 
partial or complete system failures, as would affect structural 
performance.

Discussion

    Active flight-control systems are capable of providing automatic 
responses to external inputs from sources other than pilots. These 
systems have been expanded in function, effectiveness, and reliability 
such that fly-by-wire flight controls, without a manual backup system 
in the event of system failures, are becoming standard equipment on 
larger transport-category airplanes. As a result of these advancements 
in flight-control technology, the current safety standards contained in 
part 25 do not provide an adequate basis to address an acceptable level 
of safety for airplanes equipped with these advanced systems. Instead, 
certification of these systems has been achieved by issuance of special 
conditions under the provisions of Sec.  21.16.
    For example, stability-augmentation systems (SAS), and to a lesser 
extent load-alleviation systems (LAS), have been used on transport-
category airplanes for many years. Past approvals of these systems were 
based on both special conditions and individual findings of equivalent 
level of safety with existing rules.
    Although autopilots are also considered active control systems, 
typically their control authority has been limited such that the 
consequences of system failures could be readily counteracted by the 
pilot. Now, autopilot functions are integrated into the primary flight 
controls and are given sufficient control authority to maneuver the 
airplane to its structural design limits. This advanced technology, 
with its expanded authority, requires a new approach to account for the 
interaction of control systems and structures.
    The usual deterministic approach to defining the loads envelope 
contained in part 25 does not fully account for system effectiveness 
and system reliability. These automatic systems may be inoperative or 
may operate in a degraded mode with less than full system authority. 
Therefore, it is necessary to determine the structural factors of 
safety and operating margins such that the joint probability of 
structural failures, due to application of loads during system 
malfunctions, is not greater than that found in airplanes equipped with 
earlier-technology control systems. To achieve this objective, it is 
necessary to define the failure conditions, with their associated 
frequency of occurrence, to determine the structural factors of safety 
and operating margins that will ensure an acceptable level of safety.
    Earlier automatic control systems usually provided two states: 
Either fully functioning, or a total loss of function. Flightcrew 
readily detected these conditions. The new, active, flight-control 
systems have failure modes that allow the system to function in the 
degraded mode without full authority. This degraded mode is not readily 
detectable by the flightcrew. Therefore, monitoring systems are 
required on these new systems to provide an annunciation of a condition 
of degraded system capability.

[[Page 50498]]

    In these special conditions, and in the current standards and 
regulations, the term ``any'' requires the applicant to address all 
items covered by the term, rather than addressing only a portion of the 
items.

Applicability

    As discussed above, these special conditions are applicable to 
Boeing Model 777-8 and 777-9 airplanes. Should Boeing apply at a later 
date for a change to the type certificate to include another model 
incorporating the same novel or unusual design feature, these special 
conditions would apply to that model as well.

Conclusion

    This action affects only a certain novel or unusual design feature 
on one model of airplane. It is not a rule of general applicability.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.
    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for Boeing Model 777-8 and 777-9 
airplanes.

Interaction of Systems and Structures

    For airplanes equipped with systems that affect structural 
performance, either directly or as a result of a failure or 
malfunction, the influence of these systems and their failure 
conditions must be taken into account when showing compliance with the 
requirements of part 25, subparts C and D.
    For airplanes equipped with flight-control systems, autopilots, 
stability-augmentation systems, load-alleviation systems, fuel-
management systems, and other systems that either directly, or as a 
result of failure or malfunction, affect structural performance, the 
following criteria must be used for showing compliance. If these 
special conditions are used for other systems, it may be necessary to 
adapt the criteria to the specific system.
    1. The criteria defined herein only address the direct structural 
consequences of the system responses and performance. They cannot be 
considered in isolation, but should be included in the overall safety 
evaluation of the airplane. These criteria may, in some instances, 
duplicate standards already established for this evaluation. These 
criteria are only applicable to structure the failure of which could 
prevent continued safe flight and landing. Specific criteria that 
define acceptable limits on handling characteristics or stability 
requirements, when operating in the system-degraded or inoperative 
mode, are not provided in these special conditions.
    2. Depending upon the specific characteristics of the airplane, 
additional studies that go beyond the criteria provided in these 
special conditions may be required to demonstrate the airplane's 
capability to meet other realistic conditions, such as alternative gust 
or maneuver descriptions for an airplane equipped with a load-
alleviation system.
    3. The following definitions are applicable to these special 
conditions.
    a. Structural performance: Capability of the airplane to meet the 
structural requirements of part 25.
    b. Flight limitations: Limitations that can be applied to the 
airplane flight conditions following an in-flight occurrence, and that 
are included in the airplane flight manual (e.g., speed limitations, 
avoidance of severe weather conditions, etc.).
    c. Operational limitations: Limitations, including flight 
limitations, that can be applied to the airplane operating conditions 
before dispatch (e.g., fuel, payload and master minimum-equipment list 
limitations).
    d. Probabilistic terms: Terms such as probable, improbable, and 
extremely improbable, as used in these special conditions, are the same 
as those used in Sec.  25.1309.
    e. Failure condition: This term is the same as that used in Sec.  
25.1309. However, these special conditions apply only to system-failure 
conditions that affect the structural performance of the airplane 
(e.g., system-failure conditions that induce loads, change the response 
of the airplane to inputs such as gusts or pilot actions, or lower 
flutter margins).

Effects of Systems on Structures

    1. General. The following criteria will be used in determining the 
influence of a system and its failure conditions on the airplane 
structure.
    2. System fully operative. With the system fully operative, the 
following apply:
    a. Limit loads must be derived in all normal operating 
configurations of the system from all the limit conditions specified in 
part 25, subpart C (or defined by special conditions or findings of 
equivalent level of safety in lieu of those specified in subpart C), 
taking into account any special behavior of such a system or associated 
functions, or any effect on the structural performance of the airplane 
that may occur up to the limit loads. In particular, any significant 
nonlinearity (rate of displacement of control surface, thresholds, or 
any other system nonlinearities) must be accounted for in a realistic 
or conservative way when deriving limit loads from limit conditions.
    b. The airplane must meet the strength requirements of part 25 
(static strength, residual strength), using the specified factors to 
derive ultimate loads from the limit loads defined above. The effect of 
nonlinearities must be investigated beyond limit conditions to ensure 
that the behavior of the system presents no anomaly compared to the 
behavior below limit conditions. However, conditions beyond limit 
conditions need not be considered when it can be shown that the 
airplane has design features that will not allow it to exceed those 
limit conditions.
    c. The airplane must meet the aeroelastic stability requirements of 
Sec.  25.629.
    3. System in the failure condition. For any system-failure 
condition not shown to be extremely improbable, the following apply:
    a. At the time of occurrence. Starting from 1g level flight 
conditions, a realistic scenario, including pilot corrective actions, 
must be established to determine the loads occurring at the time of 
failure and immediately after the failure.
    i. For static-strength substantiation, these loads, multiplied by 
an appropriate factor of safety that is related to the probability of 
occurrence of the failure, are ultimate loads to be considered for 
design. The factor of safety is defined in Figure 1, below.

[[Page 50499]]

[GRAPHIC] [TIFF OMITTED] TR01NO17.000

    ii. For residual-strength substantiation, the airplane must be able 
to withstand two thirds of the ultimate loads defined in special 
condition 3.a.i. For pressurized cabins, these loads must be combined 
with the normal operating differential pressure.
    iii. Freedom from aeroelastic instability must be shown up to the 
speeds defined in Sec.  25.629(b)(2). For failure conditions that 
result in speeds beyond VC/MC, freedom from 
aeroelastic instability must be shown to increased speeds, so that the 
margins intended by Sec.  25.629(b)(2) are maintained.
    iv. Failures of the system that result in forced structural 
vibrations (oscillatory failures) must not produce loads that could 
result in detrimental deformation of primary structure.
    b. For the continuation of the flight. For the airplane in the 
system-failed state, and considering any appropriate reconfiguration 
and flight limitations, the following apply:
    i. The loads derived from the following conditions (or defined by 
special conditions or findings of equivalent level of safety in lieu of 
the following conditions) at speeds up to VC/MC 
(or the speed limitation prescribed for the remainder of the flight) 
must be determined:
    1. the limit symmetrical maneuvering conditions specified in 
Sec. Sec.  25.331 and 25.345.
    2. the limit gust and turbulence conditions specified in Sec. Sec.  
25.341 and 25.345.
    3. the limit rolling conditions specified in Sec.  25.349, and the 
limit unsymmetrical conditions specified in Sec. Sec.  25.367, and 
25.427(b) and (c).
    4. the limit yaw-maneuvering conditions specified in Sec.  25.351.
    5. the limit ground-loading conditions specified in Sec. Sec.  
25.473, 25.491, 25.493(d), and 25.503.
    ii. For static-strength substantiation, each part of the structure 
must be able to withstand the loads in special condition 3.b.i., 
multiplied by a factor of safety depending on the probability of being 
in this failure state.
    The factor of safety is defined in Figure 2, below.
    [GRAPHIC] [TIFF OMITTED] TR01NO17.001
    
Qj = (Tj)(Pj)

Where:

Tj = Average time spent in failure mode j (in hours)
Pj = Probability of occurrence of failure mode j (per 
hour)

    Note: If Pj is greater than 10-3 per 
flight hour, then a 1.5 factor of safety must be applied to all 
limit load conditions specified in part 25, subpart C.

    iii. For residual-strength substantiation, the airplane must be 
able to withstand two-thirds of the ultimate loads defined in paragraph 
3.b.ii. of these special conditions. For pressurized cabins, these 
loads must be combined with the normal operating differential pressure.
    iv. If the loads induced by the failure condition have a 
significant effect on fatigue or damage tolerance, then their effects 
must be taken into account.
    v. Freedom from aeroelastic instability must be shown up to a speed 
determined from Figure 3, below. Flutter clearance speeds V' and V'' 
may be based on the speed limitation specified for the remainder of the 
flight using the margins defined by Sec.  25.629(b).

[[Page 50500]]

[GRAPHIC] [TIFF OMITTED] TR01NO17.002

V' = Clearance speed as defined by Sec.  25.629(b)(2).
V'' = Clearance speed as defined by Sec.  25.629(b)(1).
Qj = (Tj)(Pj)

Where:

Tj = Average time spent in failure mode j (in hours)
Pj = Probability of occurrence of failure mode j (per 
hour)

    Note: If Pj is greater than 10-3 per 
flight hour, then the flutter clearance speed must not be less than 
V''.

    vi. Freedom from aeroelastic instability must also be shown up to 
V' in Figure 3, above, for any probable system-failure condition, 
combined with any damage required or selected for investigation by 
Sec.  25.571(b).
    c. Consideration of certain failure conditions may be required by 
other sections of part 25 regardless of calculated system reliability. 
Where analysis shows the probability of these failure conditions to be 
less than 10-9 per flight hour, criteria other than those 
specified in this paragraph may be used for structural substantiation 
to show continued safe flight and landing.
    4. Failure indications. For system-failure detection and 
indication, the following apply:
    a. The system must be checked for failure conditions, not extremely 
improbable, that degrade the structural capability below the level 
required by part 25, or that significantly reduce the reliability of 
the remaining system. As far as reasonably practicable, the flightcrew 
must be made aware of these failures before flight. Certain elements of 
the control system, such as mechanical and hydraulic components, may 
use special periodic inspections, and electronic components may use 
daily checks, in lieu of detection and indication systems, to achieve 
the objective of this requirement. These certification-maintenance 
requirements must be limited to components that are not readily 
detectable by normal detection-and-indication systems, and where 
service history shows that inspections will provide an adequate level 
of safety.
    b. The existence of any failure condition, not extremely 
improbable, during flight, that could significantly affect the 
structural capability of the airplane, and for which the associated 
reduction in airworthiness can be minimized by suitable flight 
limitations, must be signaled to the flightcrew. For example, failure 
conditions that result in a factor of safety between the airplane 
strength and the loads of part 25, subpart C below 1.25, or flutter 
margins below V'', must be signaled to the crew during flight.
    5. Dispatch with known failure conditions. If the airplane is to be 
dispatched in a known system-failure condition that affects structural 
performance, or that affects the reliability of the remaining system to 
maintain structural performance, then the provisions of these special 
conditions must be met, including the provisions of special condition 2 
for the dispatched condition, and special condition 3 for subsequent 
failures.
    a. Expected operational limitations may be taken into account in 
establishing Pj as the probability of failure occurrence for 
determining the safety margin in Figure 1.
    b. Flight limitations and expected operational limitations may be 
taken into account in establishing Qj as the combined probability of 
being in the dispatched failure condition, and the subsequent failure 
condition, for the safety margins in Figures 2 and 3.
    c. These limitations must be such that the probability of being in 
this combined failure state, and then subsequently encountering limit 
load conditions, is extremely improbable. No reduction in these safety 
margins is allowed if the subsequent system-failure rate is greater 
than 10-3 per flight hour.

    Issued in Renton, Washington, on October 23, 2017.
Victor Wicklund,
Manager, Transport Standards Branch, Policy and Innovation Division, 
Aircraft Certification Service.
[FR Doc. 2017-23699 Filed 10-31-17; 8:45 am]
 BILLING CODE 4910-13-P



                                              50496            Federal Register / Vol. 82, No. 210 / Wednesday, November 1, 2017 / Rules and Regulations

                                              prohibited security. The employee shall                  the matter is no longer required. A                   novel or unusual design features when
                                              continue to be recused until the date of                 withdrawal of disqualification shall be               compared to the state of technology
                                              the DAEO’s written confirmation that                     in writing and shall be provided to the               envisioned in the airworthiness
                                              divesture has been accomplished.                         DAEO. The DAEO shall inform the                       standards for transport-category
                                                 (2) Extension of period to divest.                    employee’s supervisor that the                        airplanes. These design features include
                                              Upon a showing of undue hardship, the                    employee is no longer disqualified from               systems that, directly or as a result of
                                              DAEO may extend the 90 day period for                    the matter.                                           failure or malfunction, affect airplane
                                              divestiture specified in paragraphs (e)                                                                        structural performance. The applicable
                                              through (f) of this section.                             § 5601.104 Prohibited outside                         airworthiness regulations do not contain
                                                 (3) Disqualification pending                          employment.
                                                                                                                                                             adequate or appropriate safety standards
                                              divestiture. Pending divestiture of                        An employee shall not engage in                     for these design features. These special
                                              prohibited securities, an employee must                  outside employment, either on a paid or               conditions contain the additional safety
                                              disqualify himself or herself, in                        unpaid basis, with or for an entity on                standards that the Administrator
                                              accordance with § 2635.402 of this title,                the prohibited securities list described              considers necessary to establish a level
                                              from participation in particular matters                 in § 5601.102(b)(1)(i) through (vi).                  of safety equivalent to that established
                                              which, as a result of continued                                                                                by the existing airworthiness standards.
                                                                                                       § 5601.105 Prior approval for outside
                                              ownership of the prohibited securities,                  employment.                                           DATES: This action is effective on Boeing
                                              would affect the financial interests of                                                                        on November 1, 2017. We must receive
                                              the employee, or those of the spouse or                    (a) Prior approval for outside
                                                                                                       employment. An employee who wishes                    your comments by December 18, 2017.
                                              dependent child of the employee.
                                                                                                       to engage in outside employment, either               ADDRESSES: Send comments identified
                                                 (g) Waivers. The DAEO may grant a
                                              written waiver from this section based                   on a paid or unpaid basis, shall obtain               by docket number FAA–2017–0717
                                              on a determination that the waiver is                    the prior written approval of the DAEO.               using any of the following methods:
                                              not inconsistent with part 2635 of this                  A request for such approval shall be                     • Federal eRegulations Portal: Go to
                                              title or otherwise prohibited by law and                 submitted in writing with sufficient                  http://www.regulations.gov/and follow
                                              that, under the particular circumstances,                description of the employment to enable               the online instructions for sending your
                                              application of the prohibition is not                    the DAEO to give approval based on an                 comments electronically.
                                                                                                       informed determination that the outside                  • Mail: Send comments to Docket
                                              necessary to avoid the appearance of an
                                                                                                       employment is not expected to involve                 Operations, M–30, U.S. Department of
                                              employee’s misuse of position or loss of
                                                                                                       conduct prohibited by statute or Federal              Transportation (DOT), 1200 New Jersey
                                              impartiality, or to otherwise ensure
                                                                                                       regulation, including paragraph (a) of                Avenue SE., Room W12–140, West
                                              confidence in the impartiality and
                                                                                                       this section and part 2635 of this title.             Building Ground Floor, Washington, DC
                                              objectivity with which the
                                                                                                       The DAEO shall provide a copy of any                  20590–0001.
                                              Commission’s programs are
                                                                                                       written approvals for outside                            • Hand Delivery or Courier: Take
                                              administered, or in the case of a special
                                                                                                       employment to the employee’s                          comments to Docket Operations in
                                              Government employee, divestiture
                                                                                                       supervisor.                                           Room W12–140 of the West Building
                                              would result in substantial financial
                                                                                                         (b) Scope of approval. An employee                  Ground Floor at 1200 New Jersey
                                              hardship. A waiver under this
                                                                                                       must submit a new request for approval                Avenue SE., Washington, DC, between 9
                                              paragraph must be in writing and may
                                                                                                       upon either a significant change in the               a.m. and 5 p.m., Monday through
                                              impose conditions, such as requiring
                                                                                                       nature or scope of the outside                        Friday, except Federal holidays.
                                              execution of a written disqualification.                                                                          • Fax: Fax comments to Docket
                                                                                                       employment or a change in the
                                              § 5601.103 Notice of disqualification when               employee’s Commission position or                     Operations at 202–493–2251.
                                              seeking employment.                                      assigned responsibilities.                               Privacy: The FAA will post all
                                                 (a) An employee who has been                                                                                comments it receives, without change,
                                                                                                       [FR Doc. 2017–23764 Filed 10–31–17; 8:45 am]
                                              assigned to or is supervising work on a                                                                        to http://www.regulations.gov/,
                                                                                                       BILLING CODE 7710–FW–P
                                              particular matter that affects the                                                                             including any personal information the
                                              financial interests of a prospective                                                                           commenter provides. Using the search
                                              employer and who is required, in                                                                               function of the docket Web site, anyone
                                                                                                       DEPARTMENT OF TRANSPORTATION                          can find and read the electronic form of
                                              accordance with § 2635.604(a) of this
                                              title, to disqualify himself or herself                                                                        all comments received into any FAA
                                                                                                       Federal Aviation Administration
                                              from participation in that matter shall                                                                        docket, including the name of the
                                              provide written notice of                                                                                      individual sending the comment (or
                                                                                                       14 CFR Part 25
                                              disqualification to the DAEO within 3                                                                          signing the comment for an association,
                                              business days. The DAEO shall inform                     [Docket No. FAA–2017–0717; Special                    business, labor union, etc.). DOT’s
                                              the employee’s supervisor that the                       Conditions No. 25–704–SC]                             complete Privacy Act Statement can be
                                              employee is disqualified from the                                                                              found in the Federal Register published
                                                                                                       Special Conditions: The Boeing                        on April 11, 2000 (65 FR 19477–19478).
                                              matter. Public filers must comply with                   Company Model 777–8 and 777–9
                                              the notification requirement set forth in                                                                         Docket: Background documents or
                                                                                                       Airplanes; Interaction of Systems and                 comments received may be read at
                                              § 2635.607 of this title even when not                   Structures
                                              required to disqualify from participation                                                                      http://www.regulations.gov/ at any time.
                                              in a particular matter. Employees who                    AGENCY:  Federal Aviation                             Follow the online instructions for
                                              file a notification statement in                         Administration (FAA), DOT.                            accessing the docket or go to Docket
sradovich on DSK3GMQ082PROD with RULES




                                              compliance with § 2635.607 of this title                 ACTION: Final special conditions; request
                                                                                                                                                             Operations in Room W12–140 of the
                                              are not required to file a separate notice               for comments.                                         West Building Ground Floor at 1200
                                              under this section.                                                                                            New Jersey Avenue SE., Washington,
                                                 (b) An employee may withdraw                          SUMMARY:   These special conditions are               DC, between 9 a.m. and 5 p.m., Monday
                                              written notice under paragraph (a) of                    issued for The Boeing Company                         through Friday, except Federal holidays.
                                              this section upon determining that                       (Boeing) Model 777–8 and 777–9                        FOR FURTHER INFORMATION CONTACT:
                                              disqualification from participation in                   airplanes. These airplanes will have                  Mark Freisthler, FAA, Airframe and


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                                                               Federal Register / Vol. 82, No. 210 / Wednesday, November 1, 2017 / Rules and Regulations                                       50497

                                              Cabin Safety Branch, ANM–115,                            airplanes because of a novel or unusual               advancements in flight-control
                                              Transport Airplane Directorate, Aircraft                 design feature, special conditions are                technology, the current safety standards
                                              Certification Service, 1601 Lind Avenue                  prescribed under the provisions of                    contained in part 25 do not provide an
                                              SW., Renton, Washington 98057–3356;                      § 21.16.                                              adequate basis to address an acceptable
                                              telephone 425–227–1119; facsimile                          Special conditions are initially                    level of safety for airplanes equipped
                                              425–227–1320.                                            applicable to the model for which they                with these advanced systems. Instead,
                                              SUPPLEMENTARY INFORMATION: The                           are issued. Should the type certificate               certification of these systems has been
                                              substance of these special conditions                    for that model be amended later to                    achieved by issuance of special
                                              has been subject to the public-comment                   include any other model that                          conditions under the provisions of
                                              process in several prior instances with                  incorporates the same novel or unusual                § 21.16.
                                              no substantive comments received. The                    design features, or should any other                     For example, stability-augmentation
                                              FAA therefore finds it unnecessary to                    model already included on the same                    systems (SAS), and to a lesser extent
                                              delay the effective date and that good                   type certificate be modified to                       load-alleviation systems (LAS), have
                                              cause exists for making these special                    incorporate the same novel or unusual                 been used on transport-category
                                              conditions effective upon publication in                 design feature, these special conditions              airplanes for many years. Past approvals
                                              the Federal Register.                                    would also apply to the other model                   of these systems were based on both
                                                                                                       under § 21.101.                                       special conditions and individual
                                              Comments Invited                                           In addition to the applicable                       findings of equivalent level of safety
                                                We invite interested people to take                    airworthiness regulations and special                 with existing rules.
                                              part in this rulemaking by sending                       conditions, the Model 777–8 and 777–                     Although autopilots are also
                                              written comments, data, or views. The                    9 airplanes must comply with the fuel-                considered active control systems,
                                              most helpful comments reference a                        vent and exhaust-emission requirements                typically their control authority has
                                              specific portion of the special                          of 14 CFR part 34, and the noise-                     been limited such that the consequences
                                              conditions, explain the reason for any                   certification requirements of 14 CFR                  of system failures could be readily
                                              recommended change, and include                          part 36.                                              counteracted by the pilot. Now,
                                              supporting data.                                           The FAA issues special conditions, as               autopilot functions are integrated into
                                                We will consider all comments we                       defined in 14 CFR 11.19, in accordance                the primary flight controls and are given
                                              receive by the closing date for                          with § 11.38, and they become part of                 sufficient control authority to maneuver
                                              comments. We may change these special                    the type certification basis under                    the airplane to its structural design
                                              conditions based on the comments we                      § 21.101.                                             limits. This advanced technology, with
                                              receive.                                                                                                       its expanded authority, requires a new
                                                                                                       Novel or Unusual Design Features                      approach to account for the interaction
                                              Background                                                  The Model 777–8 and 777–9 airplanes                of control systems and structures.
                                                On April 19, 2017 (for the Model 777–                  will incorporate the following novel or                  The usual deterministic approach to
                                              8 airplane), and May 12, 2015 (for the                   unusual design features:                              defining the loads envelope contained
                                              777–9 airplane), Boeing applied for an                      These Boeing airplanes have full-time,             in part 25 does not fully account for
                                              amendment to Type Certificate (TC) No.                   digital, electronic flight-control systems            system effectiveness and system
                                              T00001SE to include the new Model                        (EFCS) affecting the pitch, yaw, and roll             reliability. These automatic systems
                                              777–8 and 777–9 airplanes. These                         axes of the airplanes. In addition, the               may be inoperative or may operate in a
                                              airplanes are derivatives of the Model                   airplanes are equipped with on-ground                 degraded mode with less than full
                                              777–300ER airplane currently approved                    load-alleviation systems to reduce                    system authority. Therefore, it is
                                              under TC No. T00001SE. The Model                         braking loads. The current regulations                necessary to determine the structural
                                              777–9 airplane is a stretched-fuselage,                  are inadequate for considering the                    factors of safety and operating margins
                                              large, twin-engine airplane with seating                 effects of these systems and their effects            such that the joint probability of
                                              for 408 passengers and a maximum                         upon structural performance. These                    structural failures, due to application of
                                              takeoff weight of 775,000 pounds.                        special conditions define the criteria to             loads during system malfunctions, is not
                                                The Model 777–8 airplane, a                            be used in the assessment of the effects              greater than that found in airplanes
                                              shortened-body derivative of the Model                   of these systems on structures.                       equipped with earlier-technology
                                              777–9 airplane, is a large, twin-engine                     The general approach of accounting                 control systems. To achieve this
                                              airplane with seating for 359 passengers                 for the effect of system failures on                  objective, it is necessary to define the
                                              and a maximum takeoff weight of                          structural performance would be                       failure conditions, with their associated
                                              775,000 pounds.                                          extended to include any partial or                    frequency of occurrence, to determine
                                                                                                       complete system failure, alone or in                  the structural factors of safety and
                                              Type Certification Basis                                 combination with other partial or                     operating margins that will ensure an
                                                 Under the provisions of title 14, Code                complete system failures, as would                    acceptable level of safety.
                                              of Federal Regulations (14 CFR) 21.101,                  affect structural performance.                           Earlier automatic control systems
                                              Boeing must show that the Model 777–                                                                           usually provided two states: Either fully
                                              8 and 777–9 airplanes meet the                           Discussion                                            functioning, or a total loss of function.
                                              applicable provisions of the regulations                    Active flight-control systems are                  Flightcrew readily detected these
                                              listed in TC No. T00001SE, or the                        capable of providing automatic                        conditions. The new, active, flight-
                                              applicable regulations in effect on the                  responses to external inputs from                     control systems have failure modes that
                                              date of application for the change,                      sources other than pilots. These systems              allow the system to function in the
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                                              except for earlier amendments as agreed                  have been expanded in function,                       degraded mode without full authority.
                                              upon by the FAA.                                         effectiveness, and reliability such that              This degraded mode is not readily
                                                 If the Administrator finds that the                   fly-by-wire flight controls, without a                detectable by the flightcrew. Therefore,
                                              applicable airworthiness regulations                     manual backup system in the event of                  monitoring systems are required on
                                              (i.e., 14 CFR part 25) do not contain                    system failures, are becoming standard                these new systems to provide an
                                              adequate or appropriate safety standards                 equipment on larger transport-category                annunciation of a condition of degraded
                                              for the Model 777–8 and 777–9                            airplanes. As a result of these                       system capability.


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                                              50498            Federal Register / Vol. 82, No. 210 / Wednesday, November 1, 2017 / Rules and Regulations

                                                In these special conditions, and in the                consequences of the system responses                  a system and its failure conditions on
                                              current standards and regulations, the                   and performance. They cannot be                       the airplane structure.
                                              term ‘‘any’’ requires the applicant to                   considered in isolation, but should be                   2. System fully operative. With the
                                              address all items covered by the term,                   included in the overall safety evaluation             system fully operative, the following
                                              rather than addressing only a portion of                 of the airplane. These criteria may, in               apply:
                                              the items.                                               some instances, duplicate standards
                                                                                                       already established for this evaluation.                 a. Limit loads must be derived in all
                                              Applicability                                                                                                  normal operating configurations of the
                                                                                                       These criteria are only applicable to
                                                As discussed above, these special                      structure the failure of which could                  system from all the limit conditions
                                              conditions are applicable to Boeing                      prevent continued safe flight and                     specified in part 25, subpart C (or
                                              Model 777–8 and 777–9 airplanes.                         landing. Specific criteria that define                defined by special conditions or
                                              Should Boeing apply at a later date for                  acceptable limits on handling                         findings of equivalent level of safety in
                                              a change to the type certificate to                      characteristics or stability requirements,            lieu of those specified in subpart C),
                                              include another model incorporating the                  when operating in the system-degraded                 taking into account any special behavior
                                              same novel or unusual design feature,                    or inoperative mode, are not provided in              of such a system or associated functions,
                                              these special conditions would apply to                  these special conditions.                             or any effect on the structural
                                              that model as well.                                         2. Depending upon the specific                     performance of the airplane that may
                                              Conclusion                                               characteristics of the airplane,                      occur up to the limit loads. In
                                                                                                       additional studies that go beyond the                 particular, any significant nonlinearity
                                                This action affects only a certain                                                                           (rate of displacement of control surface,
                                                                                                       criteria provided in these special
                                              novel or unusual design feature on one                                                                         thresholds, or any other system
                                                                                                       conditions may be required to
                                              model of airplane. It is not a rule of                                                                         nonlinearities) must be accounted for in
                                                                                                       demonstrate the airplane’s capability to
                                              general applicability.                                                                                         a realistic or conservative way when
                                                                                                       meet other realistic conditions, such as
                                              List of Subjects in 14 CFR Part 25                       alternative gust or maneuver                          deriving limit loads from limit
                                                Aircraft, Aviation safety, Reporting                   descriptions for an airplane equipped                 conditions.
                                              and recordkeeping requirements.                          with a load-alleviation system.                          b. The airplane must meet the
                                                The authority citation for these                          3. The following definitions are                   strength requirements of part 25 (static
                                              special conditions is as follows:                        applicable to these special conditions.               strength, residual strength), using the
                                                                                                          a. Structural performance: Capability              specified factors to derive ultimate loads
                                                Authority: 49 U.S.C. 106(g), 40113, 44701,
                                                                                                       of the airplane to meet the structural                from the limit loads defined above. The
                                              44702, 44704.
                                                                                                       requirements of part 25.                              effect of nonlinearities must be
                                              The Special Conditions                                      b. Flight limitations: Limitations that            investigated beyond limit conditions to
                                                Accordingly, pursuant to the                           can be applied to the airplane flight                 ensure that the behavior of the system
                                              authority delegated to me by the                         conditions following an in-flight                     presents no anomaly compared to the
                                              Administrator, the following special                     occurrence, and that are included in the              behavior below limit conditions.
                                              conditions are issued as part of the type                airplane flight manual (e.g., speed                   However, conditions beyond limit
                                              certification basis for Boeing Model                     limitations, avoidance of severe weather              conditions need not be considered when
                                              777–8 and 777–9 airplanes.                               conditions, etc.).                                    it can be shown that the airplane has
                                                                                                          c. Operational limitations:
                                              Interaction of Systems and Structures                                                                          design features that will not allow it to
                                                                                                       Limitations, including flight limitations,
                                                                                                                                                             exceed those limit conditions.
                                                 For airplanes equipped with systems                   that can be applied to the airplane
                                              that affect structural performance, either               operating conditions before dispatch                     c. The airplane must meet the
                                              directly or as a result of a failure or                  (e.g., fuel, payload and master                       aeroelastic stability requirements of
                                              malfunction, the influence of these                      minimum-equipment list limitations).                  § 25.629.
                                              systems and their failure conditions                        d. Probabilistic terms: Terms such as                 3. System in the failure condition. For
                                              must be taken into account when                          probable, improbable, and extremely                   any system-failure condition not shown
                                              showing compliance with the                              improbable, as used in these special                  to be extremely improbable, the
                                              requirements of part 25, subparts C and                  conditions, are the same as those used                following apply:
                                              D.                                                       in § 25.1309.
                                                                                                                                                                a. At the time of occurrence. Starting
                                                 For airplanes equipped with flight-                      e. Failure condition: This term is the
                                                                                                                                                             from 1g level flight conditions, a
                                              control systems, autopilots, stability-                  same as that used in § 25.1309.
                                                                                                                                                             realistic scenario, including pilot
                                              augmentation systems, load-alleviation                   However, these special conditions apply
                                                                                                                                                             corrective actions, must be established
                                              systems, fuel-management systems, and                    only to system-failure conditions that
                                                                                                                                                             to determine the loads occurring at the
                                              other systems that either directly, or as                affect the structural performance of the
                                                                                                                                                             time of failure and immediately after the
                                              a result of failure or malfunction, affect               airplane (e.g., system-failure conditions
                                                                                                                                                             failure.
                                              structural performance, the following                    that induce loads, change the response
                                              criteria must be used for showing                        of the airplane to inputs such as gusts                  i. For static-strength substantiation,
                                              compliance. If these special conditions                  or pilot actions, or lower flutter                    these loads, multiplied by an
                                              are used for other systems, it may be                    margins).                                             appropriate factor of safety that is
                                              necessary to adapt the criteria to the                                                                         related to the probability of occurrence
                                              specific system.                                         Effects of Systems on Structures                      of the failure, are ultimate loads to be
                                                 1. The criteria defined herein only                     1. General. The following criteria will             considered for design. The factor of
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                                              address the direct structural                            be used in determining the influence of               safety is defined in Figure 1, below.




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                                                               Federal Register / Vol. 82, No. 210 / Wednesday, November 1, 2017 / Rules and Regulations                                        50499




                                                 ii. For residual-strength                             loads that could result in detrimental                  2. the limit gust and turbulence
                                              substantiation, the airplane must be able                deformation of primary structure.                     conditions specified in §§ 25.341 and
                                              to withstand two thirds of the ultimate                     b. For the continuation of the flight.             25.345.
                                              loads defined in special condition 3.a.i.                For the airplane in the system-failed                   3. the limit rolling conditions
                                              For pressurized cabins, these loads must                 state, and considering any appropriate                specified in § 25.349, and the limit
                                              be combined with the normal operating                                                                          unsymmetrical conditions specified in
                                                                                                       reconfiguration and flight limitations,
                                              differential pressure.                                                                                         §§ 25.367, and 25.427(b) and (c).
                                                                                                       the following apply:
                                                                                                                                                               4. the limit yaw-maneuvering
                                                 iii. Freedom from aeroelastic                            i. The loads derived from the                      conditions specified in § 25.351.
                                              instability must be shown up to the                      following conditions (or defined by                     5. the limit ground-loading conditions
                                              speeds defined in § 25.629(b)(2). For                    special conditions or findings of                     specified in §§ 25.473, 25.491,
                                              failure conditions that result in speeds                 equivalent level of safety in lieu of the             25.493(d), and 25.503.
                                              beyond VC/MC, freedom from                               following conditions) at speeds up to                   ii. For static-strength substantiation,
                                              aeroelastic instability must be shown to                                                                       each part of the structure must be able
                                                                                                       VC/MC (or the speed limitation
                                              increased speeds, so that the margins                                                                          to withstand the loads in special
                                                                                                       prescribed for the remainder of the
                                              intended by § 25.629(b)(2) are                                                                                 condition 3.b.i., multiplied by a factor of
                                                                                                       flight) must be determined:
                                              maintained.                                                                                                    safety depending on the probability of
                                                                                                          1. the limit symmetrical maneuvering
                                                 iv. Failures of the system that result                                                                      being in this failure state.
                                                                                                       conditions specified in §§ 25.331 and
                                              in forced structural vibrations                                                                                  The factor of safety is defined in
                                                                                                       25.345.
                                              (oscillatory failures) must not produce                                                                        Figure 2, below.




                                              Qj = (Tj)(Pj)                                              iii. For residual-strength                          fatigue or damage tolerance, then their
                                              Where:                                                   substantiation, the airplane must be able             effects must be taken into account.
                                              Tj = Average time spent in failure mode j (in            to withstand two-thirds of the ultimate                  v. Freedom from aeroelastic
                                                   hours)                                              loads defined in paragraph 3.b.ii. of                 instability must be shown up to a speed
                                              Pj = Probability of occurrence of failure mode           these special conditions. For                         determined from Figure 3, below.
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                                                   j (per hour)                                        pressurized cabins, these loads must be               Flutter clearance speeds V′ and V″ may
                                                                                                       combined with the normal operating                    be based on the speed limitation
                                                                                                                                                                                                           ER01NO17.001</GPH>




                                                Note: If Pj is greater than 10¥3 per flight
                                              hour, then a 1.5 factor of safety must be                differential pressure.                                specified for the remainder of the flight
                                              applied to all limit load conditions specified             iv. If the loads induced by the failure             using the margins defined by
                                              in part 25, subpart C.                                   condition have a significant effect on                § 25.629(b).
                                                                                                                                                                                                           ER01NO17.000</GPH>




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                                              50500            Federal Register / Vol. 82, No. 210 / Wednesday, November 1, 2017 / Rules and Regulations




                                              V′ = Clearance speed as defined by                       where service history shows that                        Issued in Renton, Washington, on October
                                                   § 25.629(b)(2).                                     inspections will provide an adequate                  23, 2017.
                                              V″ = Clearance speed as defined by                       level of safety.                                      Victor Wicklund,
                                                   § 25.629(b)(1).                                        b. The existence of any failure                    Manager, Transport Standards Branch, Policy
                                              Qj = (Tj)(Pj)                                                                                                  and Innovation Division, Aircraft
                                                                                                       condition, not extremely improbable,                  Certification Service.
                                              Where:                                                   during flight, that could significantly               [FR Doc. 2017–23699 Filed 10–31–17; 8:45 am]
                                              Tj = Average time spent in failure mode j (in            affect the structural capability of the
                                                   hours)                                                                                                    BILLING CODE 4910–13–P
                                                                                                       airplane, and for which the associated
                                              Pj = Probability of occurrence of failure mode
                                                                                                       reduction in airworthiness can be
                                                   j (per hour)
                                                                                                       minimized by suitable flight limitations,             DEPARTMENT OF TRANSPORTATION
                                                Note: If Pj is greater than 10¥3 per flight            must be signaled to the flightcrew. For
                                              hour, then the flutter clearance speed must                                                                    Federal Aviation Administration
                                              not be less than V″.
                                                                                                       example, failure conditions that result
                                                                                                       in a factor of safety between the airplane
                                                 vi. Freedom from aeroelastic                          strength and the loads of part 25,                    14 CFR Part 25
                                              instability must also be shown up to V′                  subpart C below 1.25, or flutter margins
                                              in Figure 3, above, for any probable                     below V″, must be signaled to the crew                [Docket No. FAA–2017–0718; Special
                                              system-failure condition, combined                       during flight.                                        Conditions No. 25–705–SC]
                                              with any damage required or selected
                                              for investigation by § 25.571(b).                           5. Dispatch with known failure                     Special Conditions: The Boeing
                                                 c. Consideration of certain failure                   conditions. If the airplane is to be                  Company Model 777–8 and 777–9
                                              conditions may be required by other                      dispatched in a known system-failure                  Airplanes; Design Roll Maneuver for
                                              sections of part 25 regardless of                        condition that affects structural                     Electronic Flight Controls
                                              calculated system reliability. Where                     performance, or that affects the
                                              analysis shows the probability of these                  reliability of the remaining system to                AGENCY:  Federal Aviation
                                              failure conditions to be less than 10¥9                  maintain structural performance, then                 Administration (FAA), DOT.
                                              per flight hour, criteria other than those               the provisions of these special                       ACTION: Final special conditions; request
                                              specified in this paragraph may be used                  conditions must be met, including the                 for comments.
                                              for structural substantiation to show                    provisions of special condition 2 for the
                                              continued safe flight and landing.                       dispatched condition, and special                     SUMMARY:   These special conditions are
                                                 4. Failure indications. For system-                   condition 3 for subsequent failures.                  issued for The Boeing Company
                                              failure detection and indication, the                                                                          (Boeing) Model 777–8 and 777–9
                                                                                                          a. Expected operational limitations                airplanes. These airplanes will have a
                                              following apply:
                                                                                                       may be taken into account in                          novel or unusual design feature when
                                                 a. The system must be checked for
                                              failure conditions, not extremely                        establishing Pj as the probability of                 compared to the state of technology
                                              improbable, that degrade the structural                  failure occurrence for determining the                envisioned in the airworthiness
                                              capability below the level required by                   safety margin in Figure 1.                            standards for transport-category
                                              part 25, or that significantly reduce the                   b. Flight limitations and expected                 airplanes. This design feature is an
                                              reliability of the remaining system. As                  operational limitations may be taken                  electronic flight-control system (EFCS)
                                              far as reasonably practicable, the                       into account in establishing Qj as the                that provides control of the airplane
                                              flightcrew must be made aware of these                   combined probability of being in the                  through pilot inputs to the flight
                                              failures before flight. Certain elements                 dispatched failure condition, and the                 computer. The applicable airworthiness
                                              of the control system, such as                           subsequent failure condition, for the                 regulations do not contain adequate or
                                              mechanical and hydraulic components,                                                                           appropriate safety standards for this
                                                                                                       safety margins in Figures 2 and 3.
                                              may use special periodic inspections,                                                                          design feature. These special conditions
                                                                                                          c. These limitations must be such that             contain the additional safety standards
                                              and electronic components may use
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                                              daily checks, in lieu of detection and                   the probability of being in this                      that the Administrator considers
                                              indication systems, to achieve the                       combined failure state, and then                      necessary to establish a level of safety
                                              objective of this requirement. These                     subsequently encountering limit load                  equivalent to that established by the
                                              certification-maintenance requirements                   conditions, is extremely improbable. No               existing airworthiness standards.
                                              must be limited to components that are                   reduction in these safety margins is                  DATES: This action is effective on Boeing
                                              not readily detectable by normal                         allowed if the subsequent system-failure              on November 1, 2017. We must receive
                                                                                                       rate is greater than 10¥3 per flight hour.
                                                                                                                                                                                                            ER01NO17.002</GPH>




                                              detection-and-indication systems, and                                                                          your comments by December 18, 2017.


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Document Created: 2017-11-01 02:03:13
Document Modified: 2017-11-01 02:03:13
CategoryRegulatory Information
CollectionFederal Register
sudoc ClassAE 2.7:
GS 4.107:
AE 2.106:
PublisherOffice of the Federal Register, National Archives and Records Administration
SectionRules and Regulations
ActionFinal special conditions; request for comments.
DatesThis action is effective on Boeing on November 1, 2017. We must receive your comments by December 18, 2017.
ContactMark Freisthler, FAA, Airframe and Cabin Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057- 3356; telephone 425-227-1119; facsimile 425-227-1320.
FR Citation82 FR 50496 
CFR AssociatedAircraft; Aviation Safety and Reporting and Recordkeeping Requirements

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