C172 pilots make precautionary landing with rough running engine caused by bird nest in carburetor i...

Attributes
ACN	614652
Time
Date	200404
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : src.airport
State Reference	AR
Altitude	msl single value : 2200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : instructional
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	None
Person 1
Affiliation	other
Function	instruction : instructor
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 210 flight time total : 9000 flight time type : 105
ASRS Report	614652
Person 2
Affiliation	other
Function	instruction : trainee
Events
Anomaly	aircraft equipment problem : less severe ground encounters : fod
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : diverted to another airport flight crew : landed as precaution
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance Environmental Factor
Primary Problem	Environmental Factor

Narrative:

During a recent flight review with a student in an aircraft I have flown and operated before (several hours in the last 90 days). After performing a thorough preflight, we departed the pattern to do some basic air maneuvers. Approximately 10 mi from the field we had a partial power loss. Carburetor heat and mixture adjustments made it worse. Flying back to our departure field with the engine progressively running rougher, the decision was made to land at a very familiar grass strip. Postflt inspection revealed a very large bird nest in the back corner of the cowling, in front of the air alternate heater intake. Apparently the bird nest had worked itself through the alternate air intake, then into the carburetor. Landing was uneventful. After evaluating the preflight methods it was determined that you should use your flashlight for preflight during the day as well as at night.

Original NASA ASRS Text

Title: C172 PLTS MAKE PRECAUTIONARY LNDG WITH ROUGH RUNNING ENG CAUSED BY BIRD NEST IN CARB INTAKE.

Narrative: DURING A RECENT FLT REVIEW WITH A STUDENT IN AN ACFT I HAVE FLOWN AND OPERATED BEFORE (SEVERAL HRS IN THE LAST 90 DAYS). AFTER PERFORMING A THOROUGH PREFLT, WE DEPARTED THE PATTERN TO DO SOME BASIC AIR MANEUVERS. APPROX 10 MI FROM THE FIELD WE HAD A PARTIAL PWR LOSS. CARB HEAT AND MIXTURE ADJUSTMENTS MADE IT WORSE. FLYING BACK TO OUR DEP FIELD WITH THE ENG PROGRESSIVELY RUNNING ROUGHER, THE DECISION WAS MADE TO LAND AT A VERY FAMILIAR GRASS STRIP. POSTFLT INSPECTION REVEALED A VERY LARGE BIRD NEST IN THE BACK CORNER OF THE COWLING, IN FRONT OF THE AIR ALTERNATE HEATER INTAKE. APPARENTLY THE BIRD NEST HAD WORKED ITSELF THROUGH THE ALTERNATE AIR INTAKE, THEN INTO THE CARB. LNDG WAS UNEVENTFUL. AFTER EVALUATING THE PREFLT METHODS IT WAS DETERMINED THAT YOU SHOULD USE YOUR FLASHLIGHT FOR PREFLT DURING THE DAY AS WELL AS AT NIGHT.

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.

C172 pilots make precautionary landing with rough running engine caused by bird nest in carburetor intake.