What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(.4) During a simulated emergency approach to a landing area, at 75 feet AGL, the flight instructor told the student pilot to go-around. The student attempted to add full power; however, he could not fully turn off the carburetor heat. The instructor stated that the engine would not produce full power. The student retracted the flaps to 1/4-flap setting once the airplane's descent was arrested. The instructor noticed that the airplane was not climbing and took control of the airplane. The airplane impacted trees at a speed of approximately 50 mph. A week prior to the accident flight the student experienced a similar situation during a go-around following a simulated loss of engine power. The carburetor heat would not shut off and the airplane would not climb. The stuck carburetor heat control could not be duplicated by maintenance personnel. Post-accident examination of the airplane revealed impact marks indicating that the carburetor heat deflection door was in the on position at the time of the accident. The carburetor heat control cable was fractured in two, approximately 8 inches from the carburetor heat deflection door attach point. Examination of the carburetor heat control ccable revealed that u-shaped indentions had been worn into the inner wire by its metal spiral sleeve. Examination of the inner wire revealed that it could not carry its design load due to the wear marks, and had failed as a result of tensile overload. Examination of the aircraft maintenance records revealed that the carburetor cable had not been replaced since the airplane was manufactured in 1968. (-23) student pilot was demonstrating emergency landings, loss of power and best glide speed. Student pilot started go-around and had no power. Student pilot could not push the carb heat knob in. Emergency landing field was overflown and instructor pilot tried to go to the next landing field.
As the FAA filed it
(.4) DURING A SIMULATED EMERGENCY APPROACH TO A LANDING AREA, AT 75 FEET AGL, THE FLIGHT INSTRUCTOR TOLD THE STUDENT PILOT TO GO-AROUND. THE STUDENT ATTEMPTED TO ADD FULL POWER; HOWEVER, HE COULD NOT FULLY TURN OFF THE CARBURETOR HEAT. THE INSTRUCTOR STATED THAT THE ENGINE WOULD NOT PRODUCE FULL POWER. THE STUDENT RETRACTED THE FLAPS TO 1/4-FLAP SETTING ONCE THE AIRPLANE'S DESCENT WAS ARRESTED. THE INSTRUCTOR NOTICED THAT THE AIRPLANE WAS NOT CLIMBING AND TOOK CONTROL OF THE AIRPLANE. THE AIRPLANE IMPACTED TREES AT A SPEED OF APPROXIMATELY 50 MPH. A WEEK PRIOR TO THE ACCIDENT FLIGHT THE STUDENT EXPERIENCED A SIMILAR SITUATION DURING A GO-AROUND FOLLOWING A SIMULATED LOSS OF ENGINE POWER. THE CARBURETOR HEAT WOULD NOT SHUT OFF AND THE AIRPLANE WOULD NOT CLIMB. THE STUCK CARBURETOR HEAT CONTROL COULD NOT BE DUPLICATED BY MAINTENANCE PERSONNEL. POST-ACCIDENT EXAMINATION OF THE AIRPLANE REVEALED IMPACT MARKS INDICATING THAT THE CARBURETOR HEAT DEFLECTION DOOR WAS IN THE ON POSITION AT THE TIME OF THE ACCIDENT. THE CARBURETOR HEAT CONTROL CABLE WAS FRACTURED IN TWO, APPROXIMATELY 8 INCHES FROM THE CARBURETOR HEAT DEFLECTION DOOR ATTACH POINT. EXAMINATION OF THE CARBURETOR HEAT CONTROL CCABLE REVEALED THAT U-SHAPED INDENTIONS HAD BEEN WORN INTO THE INNER WIRE BY ITS METAL SPIRAL SLEEVE. EXAMINATION OF THE INNER WIRE REVEALED THAT IT COULD NOT CARRY ITS DESIGN LOAD DUE TO THE WEAR MARKS, AND HAD FAILED AS A RESULT OF TENSILE OVERLOAD. EXAMINATION OF THE AIRCRAFT MAINTENANCE RECORDS REVEALED THAT THE CARBURETOR CABLE HAD NOT BEEN REPLACED SINCE THE AIRPLANE WAS MANUFACTURED IN 1968. (-23) STUDENT PILOT WAS DEMONSTRATING EMERGENCY LANDINGS, LOSS OF POWER AND BEST GLIDE SPEED. STUDENT PILOT STARTED GO-AROUND AND HAD NO POWER. STUDENT PILOT COULD NOT PUSH THE CARB HEAT KNOB IN. EMERGENCY LANDING FIELD WAS OVERFLOWN AND INSTRUCTOR PILOT TRIED TO GO TO THE NEXT LANDING FIELD.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.