AD 83-22-51
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Viking Air Limited | DHC-7-1 | Airworthiness Directives; DeHavilland Model DHC-7 Airplanes |
| aircraft | Viking Air Limited | DHC-7-100 | Airworthiness Directives; DeHavilland Model DHC-7 Airplanes |
| aircraft | Viking Air Limited | DHC-7-101 | Airworthiness Directives; DeHavilland Model DHC-7 Airplanes |
| aircraft | Viking Air Limited | DHC-7-102 | Airworthiness Directives; DeHavilland Model DHC-7 Airplanes |
| aircraft | Viking Air Limited | DHC-7-103 | Airworthiness Directives; DeHavilland Model DHC-7 Airplanes |
Unsafe Condition
Failure of the bonding between the skin and honeycomb core of wing inner and mid fuel tank covers P/N 75710059-007 thru -014 and P/N 75711708-003 thru -006 could result in loss of strength and stiffness of the wing.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect upper surfaces of wing inner and mid fuel tank covers using ultrasonic tester or coin test. Replace covers with unbonded surfaces before further flight. Repetitive inspections may be terminated with installation of P/N 7Z4096-001 (Inner) and P/N 7Z4097-001 (Middle).
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
within the next 10 hours time in service, unless previously accomplished within the past 490 hours and thereafter at intervals not to exceed 500 hours time in service from the last inspection
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Affected Aircraft
DeHavilland Model DHC-7 airplanes Serial Numbers 3 through 27 with wing fuel tank covers P/N 75710059-007 thru -014 (Inner) and P/N 75711708-003 thru -006 (Middle)
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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