A-77-061
NTSB Safety Recommendation — Aviation
Recommendation text
ISSUE AN AIRWORTHINESS DIRECTIVE, APPLICABLE TO THE SIKORSKY S-58T HELICOPTERS, TO REQUIRE THE INSTALLATION OF A FUEL STRAINER OR FILTER BETWEEN THE FUEL TANK OUTLET AND THE INLET OF THE OIL-TO-FUEL HEATER ASSEMBLY TO PREVENT CONTAMINANTS OF A SUFFICIENT SIZE TO CLOG OIL-TO-FUEL HEATER PASSAGES, OR, IF THE FILTER INSTALLATION IS NOT TECHNICALLY FEASIBLE BECAUSE OF PHYSICAL CONSTRAINTS, REQUIRE MODIFICATION OF THE EXISTING OIL-TO-FUEL HEATER TO INCLUDE A FUEL BYPASS PATH ACTIVATED BY A PRESSURE DIFFERENTIAL SENSING DEVICE AND AN IMPENDING BYPASS WARNING LIGHT SYSTEM. (URGENT)
In plain language (FlightFinder summary)
The FAA is urged to issue a directive requiring Sikorsky S-58T helicopters to install a fuel filter before the oil-to-fuel heater to stop debris from clogging its internal passages. If adding a filter is physically impossible due to space limitations, the agency must instead mandate a modified heater design that includes an automatic bypass system and a warning light to alert pilots when pressure differences indicate a blockage.
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 | Jun 22, 1978 |
| NTSB number | OAK77FA037 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).