A-74-054
NTSB Safety Recommendation — Aviation
Recommendation text
ISSUE AN AIRWORTHINESS DIRECTIVE TO REQUIRE THE FOLLOWING MODIFICATIONS ON OR BEFORE THE NEXT 100-HOUR INSPECTION TO UNMODIFIED TURBOCHARGED POWERPLANTS USED ON CESSNA SERIES AIRCRAFT: A. COOLING OIL JET TO ELIMINATE COKING. B. DUAL PORT SCAVENGE PUMP TO PROVIDE BETTER SCAVENGE OF THE TURBOCHARGER SYSTEM. C. REDESIGN RELIEF VALVE (AIRESEARCH DRAWING NO. 470930) TO ASSURE THAT THE POPPET WILL REMAIN IMPALED ON THE GUIDE PIN.
In plain language (FlightFinder summary)
The NTSB urged the FAA to mandate immediate engine modifications for specific Cessna aircraft with turbocharged engines to prevent mechanical failures. These required changes aim to stop oil from breaking down and clogging parts, improve the removal of used oil, and ensure a critical safety valve component stays securely in place during operation.
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 - Unacceptable Action |
|---|---|
| Mode | Aviation |
| Closed | Sep 17, 1974 |
| NTSB number | LAX74IL006 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).