A-90-164
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: ISSUE AN AIRWORTHINESS DIRECTIVE APPLICABLE TO TEXTRON LYCOMING MODE TIO-540 S1AD ENGINES REQUIRING WITHIN THE NEXT 10 HOURS OF FLIGHT, AND AT APPROPRIATE RECURRING INTERVALS THEREAFTER, AN INSPECTION AND ALIGNMENT OF THE CROSSOVER EXHAUST ASSEMBLE IN ACCORDANCE WITH PART I OF TEXTRON LYCOMING SERVICE BULLETIN NO. 484 REGARDING THIS SUBJECT OR AN UPDATED EQUIVALENT PROCEDURE TO ENSURE THE ALIGNMENT AND INTEGRITY OF EXHAUST PIPE FLANGES AND PROPER ENGAGEMENT AT THE SLIP JOINTS. (URGENT)
In plain language (FlightFinder summary)
The Federal Aviation Administration is urged to issue an airworthiness directive for certain Textron Lycoming TIO-540 S1AD engines, requiring an inspection and alignment of the crossover exhaust assembly within 10 flight hours and at recurring intervals thereafter, following Textron Lycoming Service Bulletin No. 484 or an equivalent procedure, to ensure proper flange alignment and slip joint engagement.
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 | May 6, 1993 |
| NTSB number | SEA90FA129 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).