PA28 pilot declared an emergency and diverted to a nearby airport when the engine lost power because...

Attributes
ACN	678704
Time
Date	200511
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 7500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	general aviation : personal
Make Model Name	PA-28 Cherokee/Archer II/Dakota/Pillan/Warrior
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	None
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : multi engine pilot : instrument
Experience	flight time last 90 days : 25 flight time total : 215 flight time type : 50
ASRS Report	678704
Person 2
Affiliation	government : faa
Function	controller : radar
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : rpm other flight crewa
Resolutory Action	flight crew : landed in emergency condition flight crew : diverted to another airport flight crew : declared emergency
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

While in VMC at night in cruise flight at 7500 ft MSL; there was a sudden reduction of power from 2450 RPM's to 1400-1500 RPM's and the engine started running very rough. Immediately ran through the emergency engine failure checklist; and was unable to recover sufficient power to maintain altitude. I diverted to the nearest airport which was ZZZ which I had previously overflown. I reported unable to maintain altitude to flight watch who I had previously received an en route WX briefing from. At approximately 1000 ft AGL; and 3 NM from ZZZ; I declared an emergency and notified flight watch that we may need to land on the east/west highway that was before the airport. I was able to make ZZZ without incident. After taxiing to the ramp I was greeted by emergency services. They were all very friendly and helped me secure the plane and gave a ride into town. Examined the engine the day after and found out that a valve was/is sticking intermittently causing engine to operate rough and with significant loss of power.

Original NASA ASRS Text

Title: PA28 PLT DECLARED AN EMER AND DIVERTED TO A NEARBY ARPT WHEN THE ENG LOST PWR BECAUSE OF A STICKING VALVE.

Narrative: WHILE IN VMC AT NIGHT IN CRUISE FLT AT 7500 FT MSL; THERE WAS A SUDDEN REDUCTION OF PWR FROM 2450 RPM'S TO 1400-1500 RPM'S AND THE ENG STARTED RUNNING VERY ROUGH. IMMEDIATELY RAN THROUGH THE EMER ENG FAILURE CHKLIST; AND WAS UNABLE TO RECOVER SUFFICIENT PWR TO MAINTAIN ALT. I DIVERTED TO THE NEAREST ARPT WHICH WAS ZZZ WHICH I HAD PREVIOUSLY OVERFLOWN. I RPTED UNABLE TO MAINTAIN ALT TO FLT WATCH WHO I HAD PREVIOUSLY RECEIVED AN ENRTE WX BRIEFING FROM. AT APPROX 1000 FT AGL; AND 3 NM FROM ZZZ; I DECLARED AN EMER AND NOTIFIED FLT WATCH THAT WE MAY NEED TO LAND ON THE E/W HWY THAT WAS BEFORE THE ARPT. I WAS ABLE TO MAKE ZZZ WITHOUT INCIDENT. AFTER TAXIING TO THE RAMP I WAS GREETED BY EMER SVCS. THEY WERE ALL VERY FRIENDLY AND HELPED ME SECURE THE PLANE AND GAVE A RIDE INTO TOWN. EXAMINED THE ENG THE DAY AFTER AND FOUND OUT THAT A VALVE WAS/IS STICKING INTERMITTENTLY CAUSING ENG TO OPERATE ROUGH AND WITH SIGNIFICANT LOSS OF PWR.

Data retrieved from NASA's ASRS site as of January 2009 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.

PA28 pilot declared an emergency and diverted to a nearby airport when the engine lost power because of a sticking valve.