FAA Aviation Mechanic Airframe (AMA)Airframe StructuresHard
A technician examining a wing structure finds a heavily reinforced rib located at a landing gear attachment point that, in addition to supporting airfoil shape, transmits concentrated point loads and resists compressive loads from drag/anti-drag wire bracing. This rib is best classified as which type?
- ANose rib
- BFormer rib
- CCompression rib
- DPlain rib
Show answer & explanationAnswer & explanation
Correct answer: C. Compression rib
A compression rib is a heavier, reinforced rib located at points where concentrated loads such as landing gear attachments, wing attach fittings, or wire bracing loads occur; it must carry compressive loads in addition to maintaining the wing's airfoil shape.
Why the other options are wrong
- A. A nose rib extends only from the leading edge to the front spar to maintain leading edge shape.
- B. 'Former rib' is not a standard structural wing rib classification.
- D. A plain (main) rib maintains airfoil shape but is not reinforced for concentrated compressive loads.
Compression Rib
A heavily reinforced wing rib located at points of concentrated loading, such as landing gear attach points or drag/anti-drag wire bracing, designed to resist compressive loads in addition to maintaining airfoil shape.
- Heavier construction than plain (main) ribs
- Located at concentrated load points (gear, bracing, fittings)
- Resists compressive loads from bracing wires
- Distinct from nose ribs, which only shape the leading edge
Memory trick: Compression rib = the wing's weightlifter, handling the heavy squeeze.