An aeronca 65 on a training flight has its carburetor ice up when trainee places throttle to low pos...

Attributes
ACN	392846
Time
Date	199802
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : fdk
State Reference	MD
Altitude	agl bound lower : 0 agl bound upper : 1200
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	landing other other other
Flight Plan	None
Person 1
Affiliation	Other
Function	instruction : instructor oversight : pic
Qualification	pilot : cfi
Experience	flight time last 90 days : 25 flight time total : 850 flight time type : 25
ASRS Report	392846
Person 2
Affiliation	Other
Function	flight crew : single pilot instruction : trainee
Qualification	pilot : student pilot : private
Experience	flight time type : 1
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

I was with a tailwheel student, entering on a 45 degree to downwind, runway 23 at fdk. I called '4 mi 45' and heard 2 others call 45, no distance. Student and I could not see them, but as I was concerned and at least 4 aircraft were already in pattern, I took over, cleared my right and turned out, and began to climb. I turned the controls over to my private pilot student for re-entry and he continued to turn right for re-entry. I saw conflicting traffic and pointed it out to student. He reduced the throttle and made a descending right turn to avoid. Traffic was approximately 1 1/2 mi to our 10 O'clock and slightly above, coming at us. Neither he nor I applied carburetor heat. My attention was on traffic as the 45 degree entry now had at least 3 aircraft and all of the others were faster, above, behind and presumably descending to tpa. We were then 1000 ft AGL. I told him to continue the descent and turn out again and we would wait for a better time to enter. When he advanced the throttle to level out at approximately 900 ft AGL and climb out, engine did not respond and we continued to descend. I took over the controls, applied carburetor heat, told him to check the fuel switch and began looking for a place to park. Engine began running rough with no increase in RPM, so as I was roughly 500 ft AGL downwind to a 1 mi long grass field, a rough idling engine and descending, I decided to make a landing in the field. I closed the throttle, slipped roughly 300 ft and made an uneventful landing. Student and I walked to the nearest house approximately 1/2 mi away, called the FBO. About 1 hour later, we restarted the engine, checked everything and flew back to the airport. I should have checked the carburetor heat sooner. As I know the A65 engines proclivity for icing, but I was more concerned with traffic. By the time I applied it, the engine was already affected, and I decided to land as I had an unknown situation.

Original NASA ASRS Text

Title: AN AERONCA 65 ON A TRAINING FLT HAS ITS CARB ICE UP WHEN TRAINEE PLACES THROTTLE TO LOW POS FOR DSCNT. INSTRUCTOR PLT TAKES OVER FOR A PRECAUTIONARY LNDG IN A GRASS FIELD.

Narrative: I WAS WITH A TAILWHEEL STUDENT, ENTERING ON A 45 DEG TO DOWNWIND, RWY 23 AT FDK. I CALLED '4 MI 45' AND HEARD 2 OTHERS CALL 45, NO DISTANCE. STUDENT AND I COULD NOT SEE THEM, BUT AS I WAS CONCERNED AND AT LEAST 4 ACFT WERE ALREADY IN PATTERN, I TOOK OVER, CLRED MY R AND TURNED OUT, AND BEGAN TO CLB. I TURNED THE CTLS OVER TO MY PVT PLT STUDENT FOR RE-ENTRY AND HE CONTINUED TO TURN R FOR RE-ENTRY. I SAW CONFLICTING TFC AND POINTED IT OUT TO STUDENT. HE REDUCED THE THROTTLE AND MADE A DSNDING R TURN TO AVOID. TFC WAS APPROX 1 1/2 MI TO OUR 10 O'CLOCK AND SLIGHTLY ABOVE, COMING AT US. NEITHER HE NOR I APPLIED CARB HEAT. MY ATTN WAS ON TFC AS THE 45 DEG ENTRY NOW HAD AT LEAST 3 ACFT AND ALL OF THE OTHERS WERE FASTER, ABOVE, BEHIND AND PRESUMABLY DSNDING TO TPA. WE WERE THEN 1000 FT AGL. I TOLD HIM TO CONTINUE THE DSCNT AND TURN OUT AGAIN AND WE WOULD WAIT FOR A BETTER TIME TO ENTER. WHEN HE ADVANCED THE THROTTLE TO LEVEL OUT AT APPROX 900 FT AGL AND CLB OUT, ENG DID NOT RESPOND AND WE CONTINUED TO DSND. I TOOK OVER THE CTLS, APPLIED CARB HEAT, TOLD HIM TO CHK THE FUEL SWITCH AND BEGAN LOOKING FOR A PLACE TO PARK. ENG BEGAN RUNNING ROUGH WITH NO INCREASE IN RPM, SO AS I WAS ROUGHLY 500 FT AGL DOWNWIND TO A 1 MI LONG GRASS FIELD, A ROUGH IDLING ENG AND DSNDING, I DECIDED TO MAKE A LNDG IN THE FIELD. I CLOSED THE THROTTLE, SLIPPED ROUGHLY 300 FT AND MADE AN UNEVENTFUL LNDG. STUDENT AND I WALKED TO THE NEAREST HOUSE APPROX 1/2 MI AWAY, CALLED THE FBO. ABOUT 1 HR LATER, WE RESTARTED THE ENG, CHKED EVERYTHING AND FLEW BACK TO THE ARPT. I SHOULD HAVE CHKED THE CARB HEAT SOONER. AS I KNOW THE A65 ENGS PROCLIVITY FOR ICING, BUT I WAS MORE CONCERNED WITH TFC. BY THE TIME I APPLIED IT, THE ENG WAS ALREADY AFFECTED, AND I DECIDED TO LAND AS I HAD AN UNKNOWN SIT.

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.

An aeronca 65 on a training flight has its carburetor ice up when trainee places throttle to low position for descent. Instructor pilot takes over for a precautionary landing in a grass field.