Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Pilatus Aircraft Ltd. (Pilatus) Model PC-7 airplanes with any Lear Romec RR53710B type or Lear Romec RR53710K fuel booster pump (Pilatus part number 968.84.11.401; 968.84.11.403; or 968.84.11.404) installed. This proposed AD would require you to check the airplane logbook to determine whether any installed fuel booster pump has been modified with spiral wrap to protect the wire leads and has the suffix letter "B" added to the serial number of the fuel booster pump identification plate. If any installed fuel booster pump has not been modified, you are required to inspect any installed fuel booster pump wire lead for defects; if defects are found, replace the fuel booster pump with a modified fuel booster pump with spiral wrap that protects the wire leads; or if no defects are found, install spiral wrap to protect any wire leads and adding the suffix letter "B" to the serial number of the fuel booster pumpidentification plate. The pilot is allowed to do the logbook check. If the pilot can positively determine that the fuel booster pump wire leads with spiral wrap are installed following the service information and that the suffix letter "B" is included in the serial number of the fuel booster pump identification plate, no further action is required. This proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. We are issuing this proposed AD to detect and correct any defects in the leads of any fuel booster pump, which could result in electrical arcing. This failure could lead to a fire or explosion in the fuel tank.