Airworthiness Directive · Amendment 39-16035 · Flight controls
Boeing Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, and 747SR Series Airplanes
This AD applies to Boeing Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, and 747SR series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 747-27-2422, dated October 30, 2008.
We are adopting a new airworthiness directive (AD) for certain Boeing Model 747 airplanes identified above. This AD requires replacing the inboard trailing edge (TE) flap transmission carbon disk no-back brakes with skewed roller no-back brakes at the TE flap transmission, positions 4 and 5. This AD results from reports of the inboard TE flaps blowing back due to the failure of a transmission carbon disk no-back brake. The no-back brake did not hold the TE flaps in the commanded position. We are issuing this AD to prevent a decrease of the aerodynamic controllability of the airplane, which could adversely affect the airplane's continued safe flight and landing.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 5 years after the effective date of this AD, replace the trailing edge flap transmission no-back brakes with skewed roller no-back brakes at the trailing edge flap transmission, positions 4 and 5, in accordance with Boeing Special Attention Service Bulletin 747-27-2422, dated October 30, 2008.
