Advisory Circular (AC) 91-MA, Continued Airworthiness of Older Small Transport and Commuter Airplanes; Establishment of Damage- Tolerance-Based Inspections and Procedures

[Federal Register Volume 64, Number 63 (Friday, April 2, 1999)]
[Notices]
[Page 16321]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-7445]



Federal Register / Vol. 64, No. 63 / Friday, April 2, 1999 / 
Notices

[[Page 16321]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Advisory Circular (AC) 91-MA, Continued Airworthiness of Older 
Small Transport and Commuter Airplanes; Establishment of Damage-
Tolerance-Based Inspections and Procedures

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of availability and request for comments.

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SUMMARY: This notice announces the availability of and request for 
comments on proposed AC 91-MA, which provides information and guidance 
to manufacturers and operators for use in developing contained 
structural integrity programs to ensure the safe operation of small 
transport and commuter airplanes throughout their operational usage. 
The material provides an acceptable means, but not the only means, of 
showing compliance with the operational requirements of the Federal 
Aviation Regulations applicable to the establishment of a damage-
tolerance-based inspections and procedures.

DATES: Comments must be received on or before August 2, 1999.

ADDRESSES: Send all comments on the proposed AC to: Bobby Sexton, ACE-
102, Aging Airplane Program Manager, Small Airplane Directorate, 
Central Region, Federal Aviation Administration, 601 East 12th Street, 
Kansas, Missouri, 64106; telephone number (816) 426-3241.

FOR FURTHER INFORMATION CONTACT: Bobby Sexton, ACE-102, Aging Airplane 
Program Manager, Small Airplane Directorate, Central Region, Federal 
Aviation Administration, 601 East 12th Street, Kansas, Missouri, 64106; 
telephone number: (816) 426-3241.

SUPPLEMENTARY INFORMATION:

Comments Invited

    A copy of the draft AC may be obtained by accessing the FAA's 
webgage at https://www.faa.gov/avr/arm/nprm/nprm.htm. Interested parties 
are invited to submit comments on the proposed AC. Commenters must 
identify AC 91-MA, and submit comments to the address specified above. 
All communications received on or before the closing date for comments 
will be considered by the FAA before issuing the final AC.

Discussion

    Service experience has revealed a need to assess the continuing 
airworthiness of small transport and commuter sized airplanes as they 
age. The structural integrity of these airplanes should be assessed on 
the basis of the most modern tools of analyses, testing, and 
nondestructive inspections in conjunction with the gathering of 
operational service experience. Fatigue cracking is usage dependent 
and, if left uncorrected, will degrade the integrity of the airframe to 
unsafe levels. Additional inspections, component modification, or 
structural component replacement may be essential to maintain the 
required level of safety.
    Increased utilization, longer operation, and the high safety 
demands imposed on airplanes currently operating in air transportation 
service indicates that there is a need for a program to provide a high 
level of structural integrity for all airplanes in the commuter air 
transportation fleet. Accordingly, the program outlined in the draft AC 
is intended to describe a structural integrity assessment of each 
airplane type, to be accomplished by its manufacturer or other 
competent engineering organization have access to design data; and the 
adaptation of the results of that assessment into each operator's 
maintenance program.

    Issued in Washington, DC on March 19, 1999.
L. Nicholas Lacey,
Director, Flight Standards Service.
[FR Doc. 99-7445 Filed 4-1-99; 8:45 am]
BILLING CODE 4910-13-M