Which maintenance action is an airframe major repair?

Which maintenance action is an airframe major repair?

• A. Repair of a cracked window
• B. Replacement of an avionics unit
• C. Repair of wiring harness insulation
• D. The repair of portions of skin sheet by making additional seams

Answer: (D)

Major repairs on the airframe are substantial structural work that alters a load-bearing part of the aircraft, such as the skin, frames, or spars, and requires engineering data and airworthiness approval because it changes how the airframe carries load and maintains strength. Repairing portions of skin sheet by adding additional seams directly changes the airframe’s structural surface and its load paths, making it a significant, structural repair. The other actions involve systems or non-structural components—glazing or windows, avionics, or wiring insulation—so they fall outside the airframe major-repair category.

Major repairs on the airframe are substantial structural work that alters a load-bearing part of the aircraft, such as the skin, frames, or spars, and requires engineering data and airworthiness approval because it changes how the airframe carries load and maintains strength. Repairing portions of skin sheet by adding additional seams directly changes the airframe’s structural surface and its load paths, making it a significant, structural repair. The other actions involve systems or non-structural components—glazing or windows, avionics, or wiring insulation—so they fall outside the airframe major-repair category.