Internal Ring
No failure report names the internal ring. 3 FAA approvals let 1 company make a replacement internal ring, Kapco holding the most (3).
Approved replacement parts 3 parts manufacturer approvals
A parts manufacturer approval (PMA) lets a company other than the aircraft's maker make a internal ring and sell it as an approved part for the models named. These are the companies holding such approvals for a internal ring:
| Maker | Part | Replaces | Fits | Granted | Status |
|---|---|---|---|---|---|
| Kapco | .094 Internal O-Ring VL1178PW45 | 420852 | Pratt & Whitney PW2037, PW2040) | 2019-04-14 | current |
| Kapco | .063 Internal O-Ring VL1148PW27 | 331322 | Pratt & Whitney JT8D-1, JT8D-1A, JT8D-1B | 2019-04-14 | current |
| Kapco | .094 Internal O-Ring VL1146PW25 | 495873 | Pratt & Whitney JT8D-1, JT8D-1A, JT8D-1B | 2019-03-17 | current |
Sources: the FAA's service difficulty reports since 1995 (a report is a part that failed and was fixed, as filed by an airline, repair station or owner; the count shows reporting as much as reliability) and the parts manufacturer approvals in the FAA's Dynamic Regulatory System. The part name is the reporters' and the approval holders' own words, reduced to the first plain words so that spellings meet.