SR22 pilot declares an emergency due to engine partial power loss and makes a precautionary landing.

Attributes
ACN	623655
Time
Date	200407
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 15000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zzz.artcc tower : zzz.tower
Operator	general aviation : personal
Make Model Name	SR22
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : commercial pilot : cfi pilot : multi engine
Experience	flight time last 90 days : 150 flight time total : 2700 flight time type : 900
ASRS Report	623655
Person 2
Affiliation	government : faa
Function	controller : approach
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure
Resolutory Action	controller : provided flight assist flight crew : diverted to another airport flight crew : declared emergency
Consequence	faa : reviewed incident with flight crew Other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft

Narrative:

I did a thorough preflight before leaving ZZZ on an IFR flight. All engine indications were normal for the first 25 mins of the flight, but then, while climbing through 15000 ft (I was filed for 17000 ft), it started sputtering as if it was not getting fuel. The reason I saw this is because the engine was not running 'rough,' it just went into a coast mode only occasionally (every 30 seconds or so) trying to come back to life. I set up for best glide which was not far below best rate of climb speed and advised ATC that I had lost power, while simultaneously working through the emergency checklist. Center asked my intentions and I told them I wanted to divert to ZZZ. Center then asked if I could maintain 14000 ft. I replied negative as I was already descending through that altitude without power. Center asked me if I could hold another slightly lower altitude (can't remember exactly what) and I again replied negative as I was still without power. At that point I decided to declare an emergency to unequivocally let center know that I needed priority handling and that I would be circling down to a landing. Center was helpful and friendly and as I descended through 10000 ft, they handed me off to approach. Approach asked if I had ZZZ in sight. I told them yes, and that I was canceling IFR and would let them know by phone that I was ok once I landed. Descending through 9000 ft, the engine came back to life as suddenly as it quit. I made a precautionary landing ZZZ and tried to troubleshoot the problem. After discussion with mechanics, and with them not being able to find any problems, it was decided that I may have experienced vapor lock. During the climb, I had turned off the fuel pump climbing through about 8000 ft. From now on, I am going to leave the fuel pump on during the entire climb and for the initial 10 mins of cruise flight to minimize the chance of a reoccurrence.

Original NASA ASRS Text

Title: SR22 PLT DECLARES AN EMER DUE TO ENG PARTIAL PWR LOSS AND MAKES A PRECAUTIONARY LNDG.

Narrative: I DID A THOROUGH PREFLT BEFORE LEAVING ZZZ ON AN IFR FLT. ALL ENG INDICATIONS WERE NORMAL FOR THE FIRST 25 MINS OF THE FLT, BUT THEN, WHILE CLBING THROUGH 15000 FT (I WAS FILED FOR 17000 FT), IT STARTED SPUTTERING AS IF IT WAS NOT GETTING FUEL. THE REASON I SAW THIS IS BECAUSE THE ENG WAS NOT RUNNING 'ROUGH,' IT JUST WENT INTO A COAST MODE ONLY OCCASIONALLY (EVERY 30 SECONDS OR SO) TRYING TO COME BACK TO LIFE. I SET UP FOR BEST GLIDE WHICH WAS NOT FAR BELOW BEST RATE OF CLB SPD AND ADVISED ATC THAT I HAD LOST PWR, WHILE SIMULTANEOUSLY WORKING THROUGH THE EMER CHKLIST. CTR ASKED MY INTENTIONS AND I TOLD THEM I WANTED TO DIVERT TO ZZZ. CTR THEN ASKED IF I COULD MAINTAIN 14000 FT. I REPLIED NEGATIVE AS I WAS ALREADY DSNDING THROUGH THAT ALT WITHOUT PWR. CTR ASKED ME IF I COULD HOLD ANOTHER SLIGHTLY LOWER ALT (CAN'T REMEMBER EXACTLY WHAT) AND I AGAIN REPLIED NEGATIVE AS I WAS STILL WITHOUT PWR. AT THAT POINT I DECIDED TO DECLARE AN EMER TO UNEQUIVOCALLY LET CTR KNOW THAT I NEEDED PRIORITY HANDLING AND THAT I WOULD BE CIRCLING DOWN TO A LNDG. CTR WAS HELPFUL AND FRIENDLY AND AS I DSNDED THROUGH 10000 FT, THEY HANDED ME OFF TO APCH. APCH ASKED IF I HAD ZZZ IN SIGHT. I TOLD THEM YES, AND THAT I WAS CANCELING IFR AND WOULD LET THEM KNOW BY PHONE THAT I WAS OK ONCE I LANDED. DSNDING THROUGH 9000 FT, THE ENG CAME BACK TO LIFE AS SUDDENLY AS IT QUIT. I MADE A PRECAUTIONARY LNDG ZZZ AND TRIED TO TROUBLESHOOT THE PROB. AFTER DISCUSSION WITH MECHS, AND WITH THEM NOT BEING ABLE TO FIND ANY PROBS, IT WAS DECIDED THAT I MAY HAVE EXPERIENCED VAPOR LOCK. DURING THE CLB, I HAD TURNED OFF THE FUEL PUMP CLBING THROUGH ABOUT 8000 FT. FROM NOW ON, I AM GOING TO LEAVE THE FUEL PUMP ON DURING THE ENTIRE CLB AND FOR THE INITIAL 10 MINS OF CRUISE FLT TO MINIMIZE THE CHANCE OF A REOCCURRENCE.

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.