Airworthiness Directive · Amendment 39-12135 · McDonnell Douglas Model DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, DC-8-43, DC-8-51, DC-8-52, DC-8-53, DC-8-55, DC-8-61, DC-8-61F, DC-8-62, DC-8-62F, DC-8-63, DC-8-63F, DC-8F-54, and DC-8F-55 Series Airplanes
McDonnell Douglas Model DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, DC-8-43, DC-8-51, DC-8-52, DC-8-53, DC-8-55, DC-8-61, DC-8-61F, DC-8-62, DC-8-62F, DC-8-63, DC-8-63F, DC-8F-54, and DC-8F-55 Series Airplanes
The following Model DC-8 series airplanes that have been modified in accordance with Supplemental Type Certificate (STC) ST466CH, certificated in any category: DC-8-31 DC-8-55 DC-8-32 DC-8-61 DC-8-33 DC-8-61F DC-8-41 DC-8-62 DC-8-42 DC-8-62F DC-8-43 DC-8-63 DC-8-51 DC-8-63F DC-8-52 DC-8F-54 DC-8-53 DC-8F-55
This amendment adopts a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-8-31, DC-8-32, DC- 8-33, DC-8-41, DC-8-42, DC-8-43, DC-8-51, DC-8-52, DC-8-53, DC-8-55, DC-8-61, DC-8-61F, DC-8-62, DC-8-62F, DC-8-63, DC-8-63F, DC-8F-54, and DC-8F-55 series airplanes. This action requires modification of the flow control system by rerouting the bleed air ducts to warm the pitot tube lines. This action is necessary to prevent the pitot lines from freezing, which could result in erroneous or total loss of airspeed indications to the flight crew, and consequent loss of control of the airplane. This action is intended to address the identified unsafe condition.
