Small aircraft has rough engine on takeoff makes emergency landing.

Attributes
ACN	241615
Time
Date	199305
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : bdr
State Reference	CT
Altitude	agl bound lower : 700 agl bound upper : 700
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : bdr
Operator	general aviation : instructional
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	climbout : takeoff climbout : initial
Flight Plan	VFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : cfi pilot : instrument pilot : commercial
Experience	flight time last 90 days : 6 flight time total : 1890 flight time type : 200
ASRS Report	241615
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

After takeoff on runway 11, climbed to 700 ft, requested eastbound departure and was cleared on course. Began left turn, continuing climb. Heard and observed on tachometer a momentary 100-200 RPM loss with power returning to climb power. First thought was perhaps undetected water in fuel (had clean fuel preflight). Within 5 seconds RPM decreased to 2000 and engine became rough. At this point altitude was still 700 ft. Advised tower of rough engine and was cleared to land on any runway. Was in a position to be on a base for runway 24. Flew straight to the runway while executing emergency checklist. Carburetor heat/mixture/fuel pump (verify on)/primer locked/switch tanks/ try different magnetos, no change. Set up short final and landed runway 24, slightly fast. Aircraft secured. Spoke with crash crew and tower. Grounded aircraft pending inspection by maintenance. Over the next day heard 2 cfis proclaim it was 'carburetor ice,' that aircraft would be run up and high speed taxi done and if all ok aircraft would be flown. Club owner/manager said 'no-way' and aircraft held for maintenance. Aircraft checked and found 1 cylinder had lost compression and possible ignition problem at that cylinder. Aircraft in repair at this point. Oh yes, preflight and pre takeoff run-up were normal. Observations: glad emergency procedure were automatic/instinctive. Glad to have had some power that allowed return to airport. Somewhat disappointed with attitude of 'fellow' cfis that problem had to be carburetor ice. Carburetor ice did not fit events. For the future: keep emergency procedures sharp. When teaching emergency procedures will be reinforced even more. Happy/thankful my 12 yr old son and I survived my first 'power problem!'

Original NASA ASRS Text

Title: SMA HAS ROUGH ENG ON TKOF MAKES EMER LNDG.

Narrative: AFTER TKOF ON RWY 11, CLBED TO 700 FT, REQUESTED EBOUND DEP AND WAS CLRED ON COURSE. BEGAN L TURN, CONTINUING CLB. HEARD AND OBSERVED ON TACHOMETER A MOMENTARY 100-200 RPM LOSS WITH PWR RETURNING TO CLB PWR. FIRST THOUGHT WAS PERHAPS UNDETECTED WATER IN FUEL (HAD CLEAN FUEL PREFLT). WITHIN 5 SECONDS RPM DECREASED TO 2000 AND ENG BECAME ROUGH. AT THIS POINT ALT WAS STILL 700 FT. ADVISED TWR OF ROUGH ENG AND WAS CLRED TO LAND ON ANY RWY. WAS IN A POS TO BE ON A BASE FOR RWY 24. FLEW STRAIGHT TO THE RWY WHILE EXECUTING EMER CHKLIST. CARB HEAT/MIXTURE/FUEL PUMP (VERIFY ON)/PRIMER LOCKED/SWITCH TANKS/ TRY DIFFERENT MAGNETOS, NO CHANGE. SET UP SHORT FINAL AND LANDED RWY 24, SLIGHTLY FAST. ACFT SECURED. SPOKE WITH CRASH CREW AND TWR. GNDED ACFT PENDING INSPECTION BY MAINT. OVER THE NEXT DAY HEARD 2 CFIS PROCLAIM IT WAS 'CARB ICE,' THAT ACFT WOULD BE RUN UP AND HIGH SPD TAXI DONE AND IF ALL OK ACFT WOULD BE FLOWN. CLUB OWNER/MGR SAID 'NO-WAY' AND ACFT HELD FOR MAINT. ACFT CHKED AND FOUND 1 CYLINDER HAD LOST COMPRESSION AND POSSIBLE IGNITION PROB AT THAT CYLINDER. ACFT IN REPAIR AT THIS POINT. OH YES, PREFLT AND PRE TKOF RUN-UP WERE NORMAL. OBSERVATIONS: GLAD EMER PROC WERE AUTOMATIC/INSTINCTIVE. GLAD TO HAVE HAD SOME PWR THAT ALLOWED RETURN TO ARPT. SOMEWHAT DISAPPOINTED WITH ATTITUDE OF 'FELLOW' CFIS THAT PROB HAD TO BE CARB ICE. CARB ICE DID NOT FIT EVENTS. FOR THE FUTURE: KEEP EMER PROCS SHARP. WHEN TEACHING EMER PROCS WILL BE REINFORCED EVEN MORE. HAPPY/THANKFUL MY 12 YR OLD SON AND I SURVIVED MY FIRST 'PWR PROB!'

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.