AD 77-17-12
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Martin-Marietta Corporation | 404 | Airworthiness Directives; MARTIN Martin 404 Aircraft |
Unsafe Condition
Corrosion at wing spar chord splice joints at wing station 187 could lead to structural failure.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect for corrosion at wing station 187 within three months or 500 hours in service. Repeat inspections at intervals not exceeding 10,000 hours or five years for left wings and 12,000 hours or six years for right wings. For STC SA328SO-equipped airplanes, perform dye penetrant inspections for cracks and corrosion inspections without wing removal, repeating every 10,000 hours or five years. Repair or replace corroded/cracked parts before flight.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next three months or 500 hours in service, whichever occurs first, after the effective date of this AD
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Martin-Marietta Corporation Model 404 aircraft certificated in all categories, including those with STC SA328SO wing splice fittings.
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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