Navion pilot had loss of engine power.

Attributes
ACN	470905
Time
Date	200004
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : l12.airport
State Reference	CA
Altitude	msl single value : 7500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Navion Aircraft Corp Undifferentiated or Other Model
Aircraft 2
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	VFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 20 flight time total : 13127 flight time type : 165
ASRS Report	740905
Person 2
Affiliation	other
Function	other personnel
Qualification	other other : unicom operator
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : diverted to another airport flight crew : landed in emergency condition
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

Placed mixture full rich, turned electrical boost pump on, sudden power loss. Began turn and established glide toward redlands airport. Squawked 7700. Declared emergency on redlands unicom and on 121.5 MHZ. Lowered landing gear at 100 mph (hydraulic gear via engine driven pump). Sighted airport, adjusted glide speed to maximum glide approximately 65-70 mph. Adjusted flaps to lose some excess altitude. At 4000 ft, regained engine power. Continued descent profile as if no engine power, should it fail again. Made uneventful landing at redlands airport. Postflt showed small fuel leak from engine fuel pump pressure adjusting screw with boost pump on. Suspect air was being drawn through screw shaft into fuel pump to carburetor line, causing over lean mixture and loss of power. Pump is removed from aircraft for inspection, overhaul or repair.

Original NASA ASRS Text

Title: NAVION PLT HAD LOSS OF ENG PWR.

Narrative: PLACED MIXTURE FULL RICH, TURNED ELECTRICAL BOOST PUMP ON, SUDDEN PWR LOSS. BEGAN TURN AND ESTABLISHED GLIDE TOWARD REDLANDS ARPT. SQUAWKED 7700. DECLARED EMER ON REDLANDS UNICOM AND ON 121.5 MHZ. LOWERED LNDG GEAR AT 100 MPH (HYD GEAR VIA ENG DRIVEN PUMP). SIGHTED ARPT, ADJUSTED GLIDE SPD TO MAX GLIDE APPROX 65-70 MPH. ADJUSTED FLAPS TO LOSE SOME EXCESS ALT. AT 4000 FT, REGAINED ENG PWR. CONTINUED DSCNT PROFILE AS IF NO ENG PWR, SHOULD IT FAIL AGAIN. MADE UNEVENTFUL LNDG AT REDLANDS ARPT. POSTFLT SHOWED SMALL FUEL LEAK FROM ENG FUEL PUMP PRESSURE ADJUSTING SCREW WITH BOOST PUMP ON. SUSPECT AIR WAS BEING DRAWN THROUGH SCREW SHAFT INTO FUEL PUMP TO CARB LINE, CAUSING OVER LEAN MIXTURE AND LOSS OF PWR. PUMP IS REMOVED FROM ACFT FOR INSPECTION, OVERHAUL OR REPAIR.

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.