Flight instructors reported C172 student pilot experienced a flap extension issue while preparing to...

Attributes
ACN	1685857
Time
Date	201909
Local Time Of Day	1801-2400
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	Landing
Flight Plan	None
Component
Aircraft Component	Flap Control (Trailing & Leading Edge)
Person 1
Qualification	Flight Crew Commercial Flight Crew Flight Instructor Flight Crew Instrument
Experience	Flight Crew Last 90 Days 72 Flight Crew Total 291 Flight Crew Type 200
Person 2
Function	Instructor
Qualification	Flight Crew Flight Instructor Flight Crew Commercial Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 600 Flight Crew Type 550
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural Published Material / Policy Deviation - Procedural Maintenance Inflight Event / Encounter Other / Unknown

Narrative:

My student pilot was completing his long cross country requirement. I reviewed his flight plan and preflight and everything checked out to be a safe flight. The plan; plane; pilot; programming and environment were all checked out to be safe. I received a call from [student] saying his flaps did not work while landing on the second leg of his cross country into ZZZ and said there was a dent in the flap. He stated the flaps worked at his first stop at ZZZ1 and they also worked fine during the preflight. I asked him if he hit anything and he said he did not. Me and another [instructor] flew to ZZZ to see the damage and pick [the student] up. When we arrived we could see that the flaps were about 4 degrees in the down position and a massive dent in the middle of the flap. We looked in one of the connection points of the flap and noticed a metal square jammed against the rod of the flap. [The other instructor] pried at it with a screwdriver and it broke the metal square free creating a loud bang noise and the dent on the flap bumped back into place and the flap retracted to zero. We then proceeded to open the inspection panel near the area and we found a mechanics tool that is used to pop rivets in place left in the wing. We removed the tool and inspected the flap and aileron cables and they seemed to look fine and we returned the plane back to its base ZZZ2. The tool was wedged against the flap extension rod and did not allow the flaps to retract. This could have created a very dangerous situation as the aileron cables run very close to where the tool was discovered. This was the first flight since its annual inspection and it is likely it was left in the wing during that inspection. [The student] performed how he was trained and executed a no flap landing and did not try to lower the flaps anymore and the pilot and plane landed safely.

Original NASA ASRS Text

Title: Flight instructors reported C172 student pilot experienced a flap extension issue while preparing to land as the result of a tool left in the wing.

Narrative: My student pilot was completing his long cross country requirement. I reviewed his flight plan and preflight and everything checked out to be a safe flight. The plan; plane; pilot; programming and environment were all checked out to be safe. I received a call from [student] saying his flaps did not work while landing on the second leg of his cross country into ZZZ and said there was a dent in the flap. He stated the flaps worked at his first stop at ZZZ1 and they also worked fine during the preflight. I asked him if he hit anything and he said he did not. Me and another [instructor] flew to ZZZ to see the damage and pick [the student] up. When we arrived we could see that the flaps were about 4 degrees in the down position and a massive dent in the middle of the flap. We looked in one of the connection points of the flap and noticed a metal square jammed against the rod of the flap. [The other instructor] pried at it with a screwdriver and it broke the metal square free creating a loud bang noise and the dent on the flap bumped back into place and the flap retracted to zero. We then proceeded to open the inspection panel near the area and we found a mechanics tool that is used to pop rivets in place left in the wing. We removed the tool and inspected the flap and aileron cables and they seemed to look fine and we returned the plane back to its base ZZZ2. The tool was wedged against the flap extension rod and did not allow the flaps to retract. This could have created a very dangerous situation as the aileron cables run very close to where the tool was discovered. This was the first flight since its annual inspection and it is likely it was left in the wing during that inspection. [The Student] performed how he was trained and executed a no flap landing and did not try to lower the flaps anymore and the pilot and plane landed safely.

Data retrieved from NASA's ASRS site 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.