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Failure of fuel supply pressure limiting caused engine to lose power. Turning off fuel boost pump allowed engine to resume power.
| Attributes | |
| ACN | 151731 |
| Time | |
| Date | 199007 |
| Day | Sat |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : o22 |
| State Reference | CA |
| Altitude | agl bound lower : 0 agl bound upper : 1000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Operator | general aviation : personal |
| Make Model Name | Small Aircraft, Low Wing, 1 Eng, Fixed Gear |
| Flight Phase | climbout : initial descent : approach landing other |
| Flight Plan | None |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : single pilot |
| Qualification | pilot : instrument pilot : private |
| Experience | flight time last 90 days : 14 flight time total : 1050 flight time type : 800 |
| ASRS Report | 151731 |
| Events | |
| Anomaly | aircraft equipment problem : critical |
| Independent Detector | other other : unspecified cockpit |
| Resolutory Action | flight crew : overcame equipment problem |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | other |
Narrative:
Upon departing the airport, I experienced a nearly complete loss of power on climb out. I completed a 180 degree turn to return to the airport, experiencing minimal terrain clearance, and I executed the emergency checklist to no avail. Before T/D it occurred to me to turn the fuel boost pump off. Full power was immediatley restored. After landing, tests revealed that a failure in the fuel supply pressure limiting allowed the boost pump to flood the engine. In this aircraft, full boost pressure rotates the fuel pressure indicator 1 complete revolution past redline so that it again registers within the normal range and affords no alert to the pilot if he has not observed its transient behavior. At full power the engine tolerates the overpressure condition for a substantial # of seconds. When power loss occurs the fuel pressure gauge is happily stabilized at a false 'safe' indication. As it is problematical whether the pilot perceives the fault, the only certain solution, it seems to me, is to redesign the fuel pressurization and indication system to be truly 'fail safe' in this circumstance.
Original NASA ASRS Text
Title: FAILURE OF FUEL SUPPLY PRESSURE LIMITING CAUSED ENGINE TO LOSE POWER. TURNING OFF FUEL BOOST PUMP ALLOWED ENGINE TO RESUME POWER.
Narrative: UPON DEPARTING THE ARPT, I EXPERIENCED A NEARLY COMPLETE LOSS OF PWR ON CLBOUT. I COMPLETED A 180 DEG TURN TO RETURN TO THE ARPT, EXPERIENCING MINIMAL TERRAIN CLRNC, AND I EXECUTED THE EMER CHKLIST TO NO AVAIL. BEFORE T/D IT OCCURRED TO ME TO TURN THE FUEL BOOST PUMP OFF. FULL PWR WAS IMMEDIATLEY RESTORED. AFTER LNDG, TESTS REVEALED THAT A FAILURE IN THE FUEL SUPPLY PRESSURE LIMITING ALLOWED THE BOOST PUMP TO FLOOD THE ENG. IN THIS ACFT, FULL BOOST PRESSURE ROTATES THE FUEL PRESSURE INDICATOR 1 COMPLETE REVOLUTION PAST REDLINE SO THAT IT AGAIN REGISTERS WITHIN THE NORMAL RANGE AND AFFORDS NO ALERT TO THE PLT IF HE HAS NOT OBSERVED ITS TRANSIENT BEHAVIOR. AT FULL PWR THE ENG TOLERATES THE OVERPRESSURE CONDITION FOR A SUBSTANTIAL # OF SECS. WHEN PWR LOSS OCCURS THE FUEL PRESSURE GAUGE IS HAPPILY STABILIZED AT A FALSE 'SAFE' INDICATION. AS IT IS PROBLEMATICAL WHETHER THE PLT PERCEIVES THE FAULT, THE ONLY CERTAIN SOLUTION, IT SEEMS TO ME, IS TO REDESIGN THE FUEL PRESSURIZATION AND INDICATION SYSTEM TO BE TRULY 'FAIL SAFE' IN THIS CIRCUMSTANCE.
Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.