Airworthiness Directives; The Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model MD-90-30 airplanes. This AD was prompted by a report of cracking in a horizontal stabilizer rear spar cap. This AD requires repetitive inspections for any crack in the left and right side horizontal stabilizer rear spar upper caps, and repair or replacement if necessary. We are issuing this AD to address the unsafe condition on these products.