After a hard landing, a technician inspecting the lower wing skin near the main spar attachment notices a series of shallow, wavy ripples in the skin surface that were not present before the event. What is the most appropriate next step?
- ATreat the wrinkles as cosmetic and log them for monitoring at the next annual
- BApply a doubler patch over the wrinkled area without further investigation
- CInvestigate for internal structural damage, since skin wrinkling can indicate spar or rib deformation
- DBuff the skin surface smooth and return the aircraft to service
Show answer & explanationAnswer & explanation
Correct answer: C. Investigate for internal structural damage, since skin wrinkling can indicate spar or rib deformation
Wrinkling or buckling of skin, especially near primary structure like the main spar, is a classic external indicator of internal structural overload from events such as a hard landing. Per manufacturer hard-landing inspection procedures, this finding requires further investigation of the underlying structure (spar, ribs, fasteners) before any cosmetic repair or return to service, since the wrinkle may reflect buckled substructure, not just a skin surface issue.
Why the other options are wrong
- A. Skin wrinkling after a hard landing is a significant finding, not something to defer to the next annual.
- B. Applying a patch without investigating the cause could mask a serious structural failure.
- D. Buffing addresses only the surface and ignores the possibility of serious underlying structural damage.
Skin Wrinkling/Buckling After Overstress
Wavy ripples or buckling in aircraft skin, especially near spars or ribs, that can indicate internal structural deformation from overstress events like hard landings; requires further structural investigation.
- Often found near primary structure attach points
- Requires inspection per manufacturer hard-landing/overstress procedures
- May require spar/rib inspection, NDT, or disassembly to assess extent
Memory trick: Wrinkles ripple from bent bones (spar/rib) beneath