Small aircraft pilot experiences poor performance on takeoff and climb. Returns to land.

Attributes
ACN	147960
Time
Date	199006
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : lex
State Reference	KY
Altitude	agl bound lower : 0 agl bound upper : 1000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : twr tracon : phl
Operator	general aviation : instructional
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	other
Flight Plan	None
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 70 flight time total : 2200
ASRS Report	147960
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

On takeoff on 85 degrees F day, noticed longer than normal takeoff roll and very poor rate of climb. At first thought it was probably normal considering 100 hp aircraft, fully loaded on hot day, but decided to return for landing anyway to be safe. Mechanic discovered that carburetor heat cable needed adjustment and carburetor heat may have been partially on when carburetor heat control was off. Later test flight found normal performance. I wasn't previously aware that this type of malfunction was possible. Pilot who flew the plane before me also noted poor performance, but continued flight thinking it was only a result of high density altitude. He did not squawk a problem. When in doubt about a problem, pilots should check it out.

Original NASA ASRS Text

Title: SMA PLT EXPERIENCES POOR PERFORMANCE ON TKOF AND CLIMB. RETURNS TO LAND.

Narrative: ON TKOF ON 85 DEGS F DAY, NOTICED LONGER THAN NORMAL TKOF ROLL AND VERY POOR RATE OF CLB. AT FIRST THOUGHT IT WAS PROBABLY NORMAL CONSIDERING 100 HP ACFT, FULLY LOADED ON HOT DAY, BUT DECIDED TO RETURN FOR LNDG ANYWAY TO BE SAFE. MECH DISCOVERED THAT CARB HEAT CABLE NEEDED ADJUSTMENT AND CARB HEAT MAY HAVE BEEN PARTIALLY ON WHEN CARB HEAT CONTROL WAS OFF. LATER TEST FLT FOUND NORMAL PERFORMANCE. I WASN'T PREVIOUSLY AWARE THAT THIS TYPE OF MALFUNCTION WAS POSSIBLE. PLT WHO FLEW THE PLANE BEFORE ME ALSO NOTED POOR PERFORMANCE, BUT CONTINUED FLT THINKING IT WAS ONLY A RESULT OF HIGH DENSITY ALT. HE DID NOT SQUAWK A PROB. WHEN IN DOUBT ABOUT A PROB, PLTS SHOULD CHK IT OUT.

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.