A cessna 172 on approach at 7100 ft and 4 mi from end of runway when the engine stopped. Aircraft la...

Attributes
ACN	477976
Time
Date	200007
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : cpr.airport
State Reference	WY
Altitude	msl single value : 10500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : cpr.tower
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	VFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 50 flight time total : 165 flight time type : 165
ASRS Report	477976
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	aircraft equipment problem : critical non adherence other other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : oil pressure indicator other flight crewa
Resolutory Action	flight crew : landed in emergency condition other
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

At approximately XA45, I heard a loud bang followed by rough engine performance. I was in-between muddy mountain and casper mountain, level at 10500 ft. The bang sounded like it had jostled a part loose in the engine, and the roughness was similar to a fouled spark plug. I immediately turned to the northeast to look for an emergency landing area, and to avoid the mountains. When I entered cruise I leaned the mixture and checked the oil gauges and both were in normal operating range. I used a setting of approximately 2600 rpms for cruise which was giving me between 100-95 KTS indicated. I then listened to the current ATIS, and contacted the tower. I was just getting ready to close my flight plan when I heard the bang in the engine. I thought it might have just been a fouled plug or a bad magneto, so I tried to lean the mixture a bit to see if it would burn any deposits off of the spark plug. This didn't completely remedy the situation but it seemed that the engine wasn't quite as rough after I leaned the mixture slightly. As I passed hartford the engine didn't seem to show any signs of getting worse so I continued on for an extended left base for runway 21 at natrona county. I was approximately 4 mi from the end of runway 21 when the engine popped once more and completely stopped. At this point I was at 7100 ft MSL, and I noticed power lines and rolling terrain between myself and the airport so I decided to turn away from the airport, towards the north, and find the flattest field to land in. After landing I noticed that the oil temperature gauge was 5/8 of the way from the bottom of the operating range and there was no indication on the pressure gauge. Oil was spewing from the cowling and dripping down the front landing gear. It had even blown back to the main landing gear struts. Callback conversation with reporter revealed the following information: the reporter stated the engine failure was caused by a failed or stuck exhaust valve. The reporter said the aircraft incurred no damage in the off airport landing.

Original NASA ASRS Text

Title: A CESSNA 172 ON APCH AT 7100 FT AND 4 MI FROM END OF RWY WHEN THE ENG STOPPED. ACFT LANDED OFF ARPT. PWR LOSS CAUSED BY FAILED OR STUCK EXHAUST VALVE.

Narrative: AT APPROX XA45, I HEARD A LOUD BANG FOLLOWED BY ROUGH ENG PERFORMANCE. I WAS IN-BTWN MUDDY MOUNTAIN AND CASPER MOUNTAIN, LEVEL AT 10500 FT. THE BANG SOUNDED LIKE IT HAD JOSTLED A PART LOOSE IN THE ENG, AND THE ROUGHNESS WAS SIMILAR TO A FOULED SPARK PLUG. I IMMEDIATELY TURNED TO THE NE TO LOOK FOR AN EMER LNDG AREA, AND TO AVOID THE MOUNTAINS. WHEN I ENTERED CRUISE I LEANED THE MIXTURE AND CHKED THE OIL GAUGES AND BOTH WERE IN NORMAL OPERATING RANGE. I USED A SETTING OF APPROX 2600 RPMS FOR CRUISE WHICH WAS GIVING ME BTWN 100-95 KTS INDICATED. I THEN LISTENED TO THE CURRENT ATIS, AND CONTACTED THE TWR. I WAS JUST GETTING READY TO CLOSE MY FLT PLAN WHEN I HEARD THE BANG IN THE ENG. I THOUGHT IT MIGHT HAVE JUST BEEN A FOULED PLUG OR A BAD MAGNETO, SO I TRIED TO LEAN THE MIXTURE A BIT TO SEE IF IT WOULD BURN ANY DEPOSITS OFF OF THE SPARK PLUG. THIS DIDN'T COMPLETELY REMEDY THE SIT BUT IT SEEMED THAT THE ENG WASN'T QUITE AS ROUGH AFTER I LEANED THE MIXTURE SLIGHTLY. AS I PASSED HARTFORD THE ENG DIDN'T SEEM TO SHOW ANY SIGNS OF GETTING WORSE SO I CONTINUED ON FOR AN EXTENDED L BASE FOR RWY 21 AT NATRONA COUNTY. I WAS APPROX 4 MI FROM THE END OF RWY 21 WHEN THE ENG POPPED ONCE MORE AND COMPLETELY STOPPED. AT THIS POINT I WAS AT 7100 FT MSL, AND I NOTICED PWR LINES AND ROLLING TERRAIN BTWN MYSELF AND THE ARPT SO I DECIDED TO TURN AWAY FROM THE ARPT, TOWARDS THE N, AND FIND THE FLATTEST FIELD TO LAND IN. AFTER LNDG I NOTICED THAT THE OIL TEMP GAUGE WAS 5/8 OF THE WAY FROM THE BOTTOM OF THE OPERATING RANGE AND THERE WAS NO INDICATION ON THE PRESSURE GAUGE. OIL WAS SPEWING FROM THE COWLING AND DRIPPING DOWN THE FRONT LNDG GEAR. IT HAD EVEN BLOWN BACK TO THE MAIN LNDG GEAR STRUTS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ENG FAILURE WAS CAUSED BY A FAILED OR STUCK EXHAUST VALVE. THE RPTR SAID THE ACFT INCURRED NO DAMAGE IN THE OFF ARPT LNDG.

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.

A cessna 172 on approach at 7100 ft and 4 mi from end of runway when the engine stopped. Aircraft landed off airport. Power loss caused by failed or stuck exhaust valve.