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Upon retraction following a practice stall recovery; the right flap of a C-172 was found to be damaged.
| Attributes | |
| ACN | 888636 |
| Time | |
| Date | 201005 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | Skyhawk 172/Cutlass 172 |
| Operating Under FAR Part | Part 91 |
| Flight Phase | Cruise |
| Route In Use | None |
| Flight Plan | None |
| Component | |
| Aircraft Component | Flap Control (Trailing & Leading Edge) |
| Person 1 | |
| Function | Instructor |
| Qualification | Flight Crew Commercial Flight Crew Flight Instructor |
| Experience | Flight Crew Last 90 Days 39 Flight Crew Total 2700 Flight Crew Type 2300 |
| Events | |
| Anomaly | Aircraft Equipment Problem Critical |
Narrative:
I was instructing a private pilot student in preparation for his practical test. He was practicing approach to landing stalls. He had performed and recovered from a straight-ahead stall and had just recovered from a turning stall to the left. He had leveled the wings; applied full power and achieved climbing speed. As he was retracting the flaps; somewhere between the 20 and 10 degree positions; we heard a loud sound that seemed to come from the right flap area. I looked over my right shoulder and determined that the flap had fully retracted and did not appear to be damaged. The aircraft was fully controllable; so I directed the student to return to the airport and make a precautionary landing so we could check the flap while on the ground. I was concerned that if there was a flap problem lowering them could cause them to jam; or worse; lead to a split flap condition. I had the student make a no flaps landing and taxi to the ramp; where we shut down and examined the flaps.the top of the flap; where the actuator arm attaches to it; was badly buckled and the lower groove on the inboard rail showed signs of wear that had not been present during the preflight. It appears that the flap had jammed during retraction and that the noise we heard was noise the flap made when it sprung free. The flap extended and retracted normally on the ground. The flight school owner felt that the damage was due to the performance of unapproved maneuvers and that the flap motor wasn't strong enough to do the damage that occurred. We had not performed any maneuvers other than normal training maneuvers and all maneuvers were well within the limits of the normal category. A review of pertinent material indicates that there have been several cases of cessna flaps jamming and being damaged by the flap motor before the circuit breaker pops. I also found that there is a service bulletin for the flap tracks. If flap track wear is a problem; it needs to be communicated better to the maintenance community. The three mechanics who looked at the flap were unaware of the problems.
Original NASA ASRS Text
Title: Upon retraction following a practice stall recovery; the right flap of a C-172 was found to be damaged.
Narrative: I was instructing a private pilot student in preparation for his practical test. He was practicing approach to landing stalls. He had performed and recovered from a straight-ahead stall and had just recovered from a turning stall to the left. He had leveled the wings; applied full power and achieved climbing speed. As he was retracting the flaps; somewhere between the 20 and 10 degree positions; we heard a loud sound that seemed to come from the right flap area. I looked over my right shoulder and determined that the flap had fully retracted and did not appear to be damaged. The aircraft was fully controllable; so I directed the student to return to the airport and make a precautionary landing so we could check the flap while on the ground. I was concerned that if there was a flap problem lowering them could cause them to jam; or worse; lead to a split flap condition. I had the student make a no flaps landing and taxi to the ramp; where we shut down and examined the flaps.The top of the flap; where the actuator arm attaches to it; was badly buckled and the lower groove on the inboard rail showed signs of wear that had not been present during the preflight. It appears that the flap had jammed during retraction and that the noise we heard was noise the flap made when it sprung free. The flap extended and retracted normally on the ground. The flight school owner felt that the damage was due to the performance of unapproved maneuvers and that the flap motor wasn't strong enough to do the damage that occurred. We had not performed any maneuvers other than normal training maneuvers and all maneuvers were well within the limits of the normal category. A review of pertinent material indicates that there have been several cases of Cessna flaps jamming and being damaged by the flap motor before the circuit breaker pops. I also found that there is a service bulletin for the flap tracks. If flap track wear is a problem; it needs to be communicated better to the maintenance community. The three mechanics who looked at the flap were unaware of the problems.
Data retrieved from NASA's ASRS site as of April 2012 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.