What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
-This investigation involves a successful emergency landing following an enroute declared emergency and flight diversion following an uncommanded propeller over speed, and loss of RPM control.
-The PIC stated that about 1.3 hours into a planned 3.0 hour repositioning flight from F70 to sql, he experienced a sudden uncommanded propeller/engine overspeed to 3,800 RPM. The prop control was not effective in bringing the RPM down, and he had to close the throttle to bring the engine /prop speed within limits, making it impossible to maintain altitude. Over mountainous terrain, he declared an emergency to ATC, and then found he could maintain altitude with 18 inches of manifold pressure and 3000 RPM. Max allowable RPM is normally 2,700. He continued on for 10 minutes in this overspeed of RPM condition to bfl, which had a long runway with crash rescue equipment available. He landed without incident.
As the FAA filed it
-THIS INVESTIGATION INVOLVES A SUCCESSFUL EMERGENCY LANDING FOLLOWING AN ENROUTE DECLARED EMERGENCY AND FLIGHT DIVERSION FOLLOWING AN UNCOMMANDED PROPELLER OVER SPEED, AND LOSS OF RPM CONTROL.
-THE PIC STATED THAT ABOUT 1.3 HOURS INTO A PLANNED 3.0 HOUR REPOSITIONING FLIGHT FROM F70 TO SQL, HE EXPERIENCED A SUDDEN UNCOMMANDED PROPELLER/ENGINE OVERSPEED TO 3,800 RPM. THE PROP CONTROL WAS NOT EFFECTIVE IN BRINGING THE RPM DOWN, AND HE HAD TO CLOSE THE THROTTLE TO BRING THE ENGINE /PROP SPEED WITHIN LIMITS, MAKING IT IMPOSSIBLE TO MAINTAIN ALTITUDE. OVER MOUNTAINOUS TERRAIN, HE DECLARED AN EMERGENCY TO ATC, AND THEN FOUND HE COULD MAINTAIN ALTITUDE WITH 18 INCHES OF MANIFOLD PRESSURE AND 3000 RPM. MAX ALLOWABLE RPM IS NORMALLY 2,700. HE CONTINUED ON FOR 10 MINUTES IN THIS OVERSPEED OF RPM CONDITION TO BFL, WHICH HAD A LONG RUNWAY WITH CRASH RESCUE EQUIPMENT AVAILABLE. HE LANDED WITHOUT INCIDENT.
Other reports on N1354Z · 1
Matched to the same aircraft by N-number and date.