Aircraft equipment problem reciprocating engine power loss.

Attributes
ACN	311976
Time
Date	199507
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mly
State Reference	AK
Altitude	msl bound lower : 4500 msl bound upper : 4500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	other other ground : preflight
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 10 flight time total : 400 flight time type : 200
ASRS Report	311976
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : declared emergency none taken : unable other
Consequence	other
Supplementary
Primary Problem	Aircraft

Narrative:

Approximately 1 hour and 30 mins into flight, encountered rough engine. Cruise was at best economy RPM setting with mixture leaned. As soon as engine roughened, RPM dropped off 200-300 RPM. Suspected carburetor ice. Applied carburetor ice. No change in RPM. Applied power, no change. Tried switching to individual magnetos and no change. Was within glide of airstrip at a gold mine. Set up to land and landed uneventfully. Check of engine revealed apparently stuck valve on 1 cylinder and gouges on face of both top and bottom plugs. Face of piston gouged badly.

Original NASA ASRS Text

Title: ACFT EQUIP PROB RECIPROCATING ENG PWR LOSS.

Narrative: APPROX 1 HR AND 30 MINS INTO FLT, ENCOUNTERED ROUGH ENG. CRUISE WAS AT BEST ECONOMY RPM SETTING WITH MIXTURE LEANED. AS SOON AS ENG ROUGHENED, RPM DROPPED OFF 200-300 RPM. SUSPECTED CARB ICE. APPLIED CARB ICE. NO CHANGE IN RPM. APPLIED PWR, NO CHANGE. TRIED SWITCHING TO INDIVIDUAL MAGNETOS AND NO CHANGE. WAS WITHIN GLIDE OF AIRSTRIP AT A GOLD MINE. SET UP TO LAND AND LANDED UNEVENTFULLY. CHK OF ENG REVEALED APPARENTLY STUCK VALVE ON 1 CYLINDER AND GOUGES ON FACE OF BOTH TOP AND BOTTOM PLUGS. FACE OF PISTON GOUGED BADLY.

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.