AD 92-14-07
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 747-100 Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-100B Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-100B SUD Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-200B Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-200C Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-200F Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-300 Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-400 Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-400D Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
| aircraft | The Boeing Company | 747-400F Series | Airworthiness Directives; BOEING Model 747 Series Airplanes |
Unsafe Condition
Inadequate fire extinguishing agent concentration levels within the engine fire zone following engine fire system discharge due to potential damage to engine fire extinguishing tubes and tube clamps within the engine strut.
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Required Actions
Visually inspect engine number two and three fire extinguishing tubes and clamps within the engine strut. Replace or repair damaged tubes as specified in Boeing Alert Service Bulletin 747-26A2179 revisions. Reinstall tube clamps with legs oriented away from structure. Repeat inspections at intervals of 100 flight cycles or 400 hours (or 50 flight cycles/175 hours if patched). Modify per Part II of the service bulletin within 6 months of AD effective date.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 10 days after April 19, 1991 for airplanes under AD 91-08-06; within 20 days after August 20, 1992 for others. Prior to further flight if damage is found. Modifications must be done within 6 months after August 20, 1992.
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Affected Aircraft
Boeing Model 747 series airplanes equipped with General Electric CF6-80C2 engines, as listed in Boeing Alert Service Bulletin 747-26A2179 (Feb 28, 1991) and its Revisions 1 and 2 (dated Aug 6, 1991 and Dec 18, 1991).
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Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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