AD 78-16-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney Division | JT9D-20 | PRATT & WHITNEY AIRCRAFT Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-20J | PRATT & WHITNEY AIRCRAFT Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-3A | PRATT & WHITNEY AIRCRAFT Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-59A | PRATT & WHITNEY AIRCRAFT Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7 | PRATT & WHITNEY AIRCRAFT Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-70A | PRATT & WHITNEY AIRCRAFT Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7A | PRATT & WHITNEY AIRCRAFT Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7AH | PRATT & WHITNEY AIRCRAFT Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7F | PRATT & WHITNEY AIRCRAFT Model JT9D Engines |
| engine | Pratt & Whitney Division | JT9D-7H | PRATT & WHITNEY AIRCRAFT Model JT9D Engines |
Unsafe Condition
Failures of sixth stage turbine disks due to a plugged No. 4 bearing compartment oil scavenge tube.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the inside of the No. 4 bearing compartment sump for coke in accordance with Pratt & Whitney Alert Service Bulletin No. 4826. Perform a daily visual tailpipe check for oil leakage from the No. 4 bearing compartment. If leakage is noted, inspect the compartment before further flight. The compartment must be inspected within 1500 hours time in service after the AD's effective date and every 5000 hours thereafter. Clean the sump and compartment oil scavenge tube if unacceptable coke is found.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 1500 hours time in service after the effective date of this AD (September 12, 1978) and every 5000 hours time in service thereafter. Daily checks must be performed until the compartment inspection is accomplished.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Pratt & Whitney Aircraft JT9D turbofan engines not incorporating an annular strainer element in the No. 4 bearing compartment, including models JT9D-20, JT9D-20J, JT9D-3A, JT9D-59A, JT9D-7, JT9D-70A, JT9D-7A, JT9D-7AH, JT9D-7F, JT9D-7H, and others as listed.
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
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.