What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The aircraft was being flown on an instrument check ride and was on a practice approach to sdl when the aircraft engine began surging and running rough. The cfi/pilot examiner took the controls and attempted to get engine running again by switching tanks, adjusting mixture, etc. None of these actions improved the power from the engine. The engine quit and was then restarted several times but it would not produce power or continue to run on its own at a RPM higher than idle.
The CFI contacted sdl tower and declared an emergency and requested to land on rwy 03. The aircraft was cleared to the runway and landed without incident. There was no damage to the aircraft and no injury to either pilot.
As the aircraft turned off the runway the engine was able to run with sufficient power to taxi. The CFI taxied to parking and then performed an engine run-up attempting to troubleshoot the problem. It was determined that the engine would run at low RPM, but as the throttle was advanced the fuel pressure would drop below the lower redline. This happened whether the electric fuel pump was engaged or not.
The aircraft was parked at sdl until company maintenance could make a determination of the problem.
Once maintenance performed troubleshooting it was determined that the aircraft electric fuel pump had some kind of blockage which would only allow a dribble of fuel into the engine fuel system. The electric fuel pump was removed and replaced with a new fuel pump. The engine was test run and produced normal power throught its performance parameters. The aircraft was then returned to service.
This aircraft has been operating normally since the replacement of the electric fuel pump.
Maintenance personnel later opened the electric driven fuel pump to determine why fuel flow was being restricted. During teardown it was noted that the valve seat on the intake side of the pump was missing part of the metal (brass) valve seat and the plunger was cocked sideways. Upon further inspection it was determined that the valve plunger was stuck to its seat. It appears that the plunger was jammed and would not allow fuel to flow freely into the valve body.
The maintenance provider has submitted a SDR report. A review of the maintenance records for this aircraft indicates the fuel pump has never been changed since the aircraft was certificated. Further investigation will be conducted to determine whether parts within the pump need to be assessed for wear.
As the FAA filed it
THE AIRCRAFT WAS BEING FLOWN ON AN INSTRUMENT CHECK RIDE AND WAS ON A PRACTICE APPROACH TO SDL WHEN THE AIRCRAFT ENGINE BEGAN SURGING AND RUNNING ROUGH. THE CFI/PILOT EXAMINER TOOK THE CONTROLS AND ATTEMPTED TO GET ENGINE RUNNING AGAIN BY SWITCHING TANKS, ADJUSTING MIXTURE, ETC. NONE OF THESE ACTIONS IMPROVED THE POWER FROM THE ENGINE. THE ENGINE QUIT AND WAS THEN RESTARTED SEVERAL TIMES BUT IT WOULD NOT PRODUCE POWER OR CONTINUE TO RUN ON ITS OWN AT A RPM HIGHER THAN IDLE.
THE CFI CONTACTED SDL TOWER AND DECLARED AN EMERGENCY AND REQUESTED TO LAND ON RWY 03. THE AIRCRAFT WAS CLEARED TO THE RUNWAY AND LANDED WITHOUT INCIDENT. THERE WAS NO DAMAGE TO THE AIRCRAFT AND NO INJURY TO EITHER PILOT.
AS THE AIRCRAFT TURNED OFF THE RUNWAY THE ENGINE WAS ABLE TO RUN WITH SUFFICIENT POWER TO TAXI. THE CFI TAXIED TO PARKING AND THEN PERFORMED AN ENGINE RUN-UP ATTEMPTING TO TROUBLESHOOT THE PROBLEM. IT WAS DETERMINED THAT THE ENGINE WOULD RUN AT LOW RPM, BUT AS THE THROTTLE WAS ADVANCED THE FUEL PRESSURE WOULD DROP BELOW THE LOWER REDLINE. THIS HAPPENED WHETHER THE ELECTRIC FUEL PUMP WAS ENGAGED OR NOT.
THE AIRCRAFT WAS PARKED AT SDL UNTIL COMPANY MAINTENANCE COULD MAKE A DETERMINATION OF THE PROBLEM.
ONCE MAINTENANCE PERFORMED TROUBLESHOOTING IT WAS DETERMINED THAT THE AIRCRAFT ELECTRIC FUEL PUMP HAD SOME KIND OF BLOCKAGE WHICH WOULD ONLY ALLOW A DRIBBLE OF FUEL INTO THE ENGINE FUEL SYSTEM. THE ELECTRIC FUEL PUMP WAS REMOVED AND REPLACED WITH A NEW FUEL PUMP. THE ENGINE WAS TEST RUN AND PRODUCED NORMAL POWER THROUGHT ITS PERFORMANCE PARAMETERS. THE AIRCRAFT WAS THEN RETURNED TO SERVICE.
THIS AIRCRAFT HAS BEEN OPERATING NORMALLY SINCE THE REPLACEMENT OF THE ELECTRIC FUEL PUMP.
MAINTENANCE PERSONNEL LATER OPENED THE ELECTRIC DRIVEN FUEL PUMP TO DETERMINE WHY FUEL FLOW WAS BEING RESTRICTED. DURING TEARDOWN IT WAS NOTED THAT THE VALVE SEAT ON THE INTAKE SIDE OF THE PUMP WAS MISSING PART OF THE METAL (BRASS) VALVE SEAT AND THE PLUNGER WAS COCKED SIDEWAYS. UPON FURTHER INSPECTION IT WAS DETERMINED THAT THE VALVE PLUNGER WAS STUCK TO ITS SEAT. IT APPEARS THAT THE PLUNGER WAS JAMMED AND WOULD NOT ALLOW FUEL TO FLOW FREELY INTO THE VALVE BODY.
THE MAINTENANCE PROVIDER HAS SUBMITTED A SDR REPORT. A REVIEW OF THE MAINTENANCE RECORDS FOR THIS AIRCRAFT INDICATES THE FUEL PUMP HAS NEVER BEEN CHANGED SINCE THE AIRCRAFT WAS CERTIFICATED. FURTHER INVESTIGATION WILL BE CONDUCTED TO DETERMINE WHETHER PARTS WITHIN THE PUMP NEED TO BE ASSESSED FOR WEAR.
Other reports on N926PA · 1
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