AD 2006-17-08
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Pratt & Whitney | PW4077D | Airworthiness Directives; Pratt & Whitney PW4077D, PW4084D, PW4090, and PW4090-3 Turbofan Engines |
Unsafe Condition
Oil leaking into the high pressure turbine (HPT) interstage cavity and igniting, leading to an engine case penetration and engine in-flight shutdown.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace the HPC exit inner and outer brush seal packs with new HPC exit inner and outer brush seal packs, or replace the HPC exit brush seal assembly with a new HPC exit brush seal assembly.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
By 3,000 cycles-in-service (CIS) since a used HPC exit inner brush seal pack and a new or refurbished HPC exit diffuser air seal land were installed in the engine, or by March 31, 2007, whichever occurs later. If on March 31, 2007, the used HPC exit inner brush seal pack coupled with a new or refurbished HPC exit diffuser air seal inner land assembly has not accumulated 3,000 CIS, then by 3,000 CIS, or December 31, 2008, whichever occurs first.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Pratt & Whitney PW4077D, PW4084D, PW4090, and PW4090-3 turbofan engines reassembled with a previously used high pressure compressor (HPC) exit inner brush seal pack, part number (P/N) 50J894-01, and a new or refurbished HPC exit diffuser air seal inner land, P/N 55H869. These engines are installed on, but not limited to, Boeing 777 airplanes.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.