Narrative:

I was conducting a training flight with a student pilot. We were flying a schweitzer (hughes) 300C helicopter after a thorough preflight inspection had been completed. The aircraft is equipped with dual controls and I was seated on the right (instructor's) side. The student performed several maneuvers from the left (pilot's) side, including normal approachs, steep approachs and maximum performance takeoffs. I took the controls after a positive exchange and explained the procedure for an autorotation. I told the student that I would demonstrate an autorotation and I entered one by closing the throttle to ground idle. I performed the maneuver according to the established procedure and I applied right pedal as the aircraft approached the ground to control for yaw. Approximately 5 ft AGL, I heard a loud 'snap' and felt the right pedal break. I lost yaw control and the aircraft began to yaw left. I managed to touch the right skid down first, followed by the left. The aircraft continued to rotate left 180 degrees before we came to a stop after sliding approximately 5 ft. An inspection of the aircraft revealed no structural or other damage besides the right pedal on the right side, which broke at the shaft below the floor. The shaft of the pedal was severed at the pin where it attaches to the lower shaft of the dual pedal control apparatus. I believe I was applying quite a bit of right pedal at the time it broke, but not an inordinate amount. The pedal did break as I applied pressure to control for yaw at the bottom of my autorotation. Simultaneously, I was applying cyclic and collective inputs to complete the maneuver. I managed to control the aircraft on the ground with the cyclic. No one was injured during this incident. Callback conversation with reporter revealed the following information: the aircraft is a 1974 vintage that is maintained by the reporter's company. No discrepancies were found on previous inspections. The break was a clean one showing no evidence of previous cracking.

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Original NASA ASRS Text

Title: CTL PEDAL BREAKS DURING LNDG FROM AN AUTOROTATION DEMONSTRATION DURING A HELI TRAINING FLT.

Narrative: I WAS CONDUCTING A TRAINING FLT WITH A STUDENT PLT. WE WERE FLYING A SCHWEITZER (HUGHES) 300C HELI AFTER A THOROUGH PREFLT INSPECTION HAD BEEN COMPLETED. THE ACFT IS EQUIPPED WITH DUAL CTLS AND I WAS SEATED ON THE R (INSTRUCTOR'S) SIDE. THE STUDENT PERFORMED SEVERAL MANEUVERS FROM THE L (PLT'S) SIDE, INCLUDING NORMAL APCHS, STEEP APCHS AND MAX PERFORMANCE TKOFS. I TOOK THE CTLS AFTER A POSITIVE EXCHANGE AND EXPLAINED THE PROC FOR AN AUTOROTATION. I TOLD THE STUDENT THAT I WOULD DEMONSTRATE AN AUTOROTATION AND I ENTERED ONE BY CLOSING THE THROTTLE TO GND IDLE. I PERFORMED THE MANEUVER ACCORDING TO THE ESTABLISHED PROC AND I APPLIED R PEDAL AS THE ACFT APCHED THE GND TO CTL FOR YAW. APPROX 5 FT AGL, I HEARD A LOUD 'SNAP' AND FELT THE R PEDAL BREAK. I LOST YAW CTL AND THE ACFT BEGAN TO YAW L. I MANAGED TO TOUCH THE R SKID DOWN FIRST, FOLLOWED BY THE L. THE ACFT CONTINUED TO ROTATE L 180 DEGS BEFORE WE CAME TO A STOP AFTER SLIDING APPROX 5 FT. AN INSPECTION OF THE ACFT REVEALED NO STRUCTURAL OR OTHER DAMAGE BESIDES THE R PEDAL ON THE R SIDE, WHICH BROKE AT THE SHAFT BELOW THE FLOOR. THE SHAFT OF THE PEDAL WAS SEVERED AT THE PIN WHERE IT ATTACHES TO THE LOWER SHAFT OF THE DUAL PEDAL CTL APPARATUS. I BELIEVE I WAS APPLYING QUITE A BIT OF R PEDAL AT THE TIME IT BROKE, BUT NOT AN INORDINATE AMOUNT. THE PEDAL DID BREAK AS I APPLIED PRESSURE TO CTL FOR YAW AT THE BOTTOM OF MY AUTOROTATION. SIMULTANEOUSLY, I WAS APPLYING CYCLIC AND COLLECTIVE INPUTS TO COMPLETE THE MANEUVER. I MANAGED TO CTL THE ACFT ON THE GND WITH THE CYCLIC. NO ONE WAS INJURED DURING THIS INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE ACFT IS A 1974 VINTAGE THAT IS MAINTAINED BY THE RPTR'S COMPANY. NO DISCREPANCIES WERE FOUND ON PREVIOUS INSPECTIONS. THE BREAK WAS A CLEAN ONE SHOWING NO EVIDENCE OF PREVIOUS CRACKING.

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.