A-85-054
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: BECAUSE OF THE LIMITED OPERATIONAL EXPERIENCE WITH ENGINES MODIFIED IN ACCORDANCE WITH SB-5510, CONDUCT A DIRECTED SAFETY INVESTIGATION OF THE PRATT & WHITNEY JT8D-15, -17, AND -17R SERIES ENGINES AS LPT MODULES ARE DISASSEMBLED TO VERIFY THE EFFECTIVENESS OF THE TIGHTER FIT BETWEEN THE 2ND STAGE LPT DISK AND THE ROTATING OUTER AIR SEAL IN PREVENTING FATIGUE CRACKING OF THE DISK AT THE AIR SEAL GROOVE.
In plain language (FlightFinder summary)
The FAA is asked to conduct a directed safety investigation of Pratt & Whitney JT8D-15, -17, and -17R series engines. As LPT modules are disassembled, the investigation must verify that a tighter fit between the 2nd stage LPT disk and the rotating outer air seal effectively prevents fatigue cracking of the disk at the air seal groove. The request is driven by limited operational experience with engines modified in accordance with service bulletin SB-5510.
This plain-language summary is written by FlightFinder to explain the recommendation above. It is not the official wording — the verbatim NTSB text is quoted above.
Details
| Status | Closed - Acceptable Action |
|---|---|
| Mode | Aviation |
| Closed | Apr 30, 1988 |
| NTSB number | DCA85RA021 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).