AD 53-15-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Lockheed Aircraft Corporation | 149-46 | LOCKHEED Models 049, 149, 649 and 749 Series Aircraft. |
| aircraft | Lockheed Aircraft Corporation | 49-46 | LOCKHEED Models 049, 149, 649 and 749 Series Aircraft. |
| aircraft | Lockheed Aircraft Corporation | 649-79 | LOCKHEED Models 049, 149, 649 and 749 Series Aircraft. |
| aircraft | Lockheed Aircraft Corporation | 649A-79 | LOCKHEED Models 049, 149, 649 and 749 Series Aircraft. |
| aircraft | Lockheed Aircraft Corporation | 749-79 | LOCKHEED Models 049, 149, 649 and 749 Series Aircraft. |
| aircraft | Lockheed Aircraft Corporation | 749A-79 | LOCKHEED Models 049, 149, 649 and 749 Series Aircraft. |
Unsafe Condition
Cracks in the forward flange of the lower front spar cap at wing Station 326, left and right, particularly in spar cap joggle areas, which may extend into the vertical leg and compromise structural integrity.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect for cracks using dye penetrant inspection or equivalent. Stop drill cracks not extending into the vertical leg unless terminating in a rivet hole, repair permanently, or install serviceable repair per LAC Drawing 325800. If cracks extend into the vertical leg, remove tank sealant for skin and web inspection, then install reinforcement per LAC Drawing 325667, change A or equivalent. Reinforce before resuming commercial operation. Reinspect periodically as specified.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
At the first arrival at the main base, unless already accomplished.
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Affected Aircraft
Lockheed Models 049, 149, 649, and 749 Series Aircraft.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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