AD 91-15-21
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 727-100 Series | Airworthiness Directives; BOEING Model 727 Series Airplanes |
| aircraft | The Boeing Company | 727-100C Series | Airworthiness Directives; BOEING Model 727 Series Airplanes |
| aircraft | The Boeing Company | 727-200 Series | Airworthiness Directives; BOEING Model 727 Series Airplanes |
| aircraft | The Boeing Company | 727-200F Series | Airworthiness Directives; BOEING Model 727 Series Airplanes |
| aircraft | The Boeing Company | 727 Series | Airworthiness Directives; BOEING Model 727 Series Airplanes |
| aircraft | The Boeing Company | 727C Series | Airworthiness Directives; BOEING Model 727 Series Airplanes |
Unsafe Condition
Fuel leaking from auxiliary fuel tanks installed in the fuselage cargo compartments could lead to fire in the cargo compartment.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Within 1,000 flight cycles, conduct an ultrasonic inspection or leak check of auxiliary fuel tanks. Within 12,000 flight cycles, perform inspections of the tank and support structure, repeated every 12,000 flight cycles. Deactivation or removal is required if leakage is detected. Alternative methods may be approved by the FAA.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 1,000 flight cycles after the effective date of this AD, and within the next 12,000 flight cycles after the effective date of this AD, with subsequent inspections at intervals not to exceed 12,000 flight cycles.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 727 series airplanes equipped with Boeing manufactured auxiliary fuel tanks in lower cargo compartments.
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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