Date: 201411
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: M-20 E Super 21
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Landing
ATC / advisory: Tower ZZZ
Aircraft component: Gear Extend/Retract Mechanism
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Private
Human factors: Training / Qualification
Second reporter function: Technician
Anomaly: Aircraft Equipment Problem Less Severe; Ground Event / Encounter Ground Strike - Aircraft
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Aircraft Aircraft Damaged; Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Declared Emergency
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: Gear up landing.  Could not get green light that gear was down.  Gear would not lock down.  Gear collapsed on landing.


Second narrative: A Mooney M20E came to our shop. The discrepancy was the landing gear was tripping the circuit breaker on extension. We found that a bearing had failed in the actuator and that the gears were binding. We repaired the actuator with a serviceable actuator gear housing; new bearings and new style 40:1 gear ratio gears to replace the older style 20:1 gear ratio as recommended by Mooney Aircraft Corporation Service Instructions SI20-112-001. The unit was bench tested and reinstalled in the aircraft. The gear system was fully tested thru 5 cycles with no issues. The aircraft was returned to service and test flown. Operation of gear system was good; no issues. Aircraft returned to owners hangar. [Recently]; I received a text; from the owner of [this airacraft]; on my phone requesting assistance in getting his gear down.  He was unsure if his gear was down or not since he did not have a gear down light illuminated on his instrument panel. He did have a visual indicator in the floor. He sent me a text with a picture of the indicator and it showed the gear to be down. He appeared unfamiliar with the emergency extension procedure and the operation of his radios. He was having trouble with his radios and was unsure if he was transmitting. I contacted the FBO; on my cell phone; and they were able to reach him on the radio. He made a fly by where they told him the mains appeared to be down but they were unsure if the nose gear was fully down. They suggested he divert to where they were more prepared for a gear up if necessary. He flew to [an alternate airport]; again with radio trouble. He made contact and made a fly by for a gear check and the tower advised the gear appeared to be down. He asked that the runway be foamed and he landed. During the landing the landing gear collapsed. No one was injured but there was damage to the airframe and propeller.  I have not been able to examine the damage or possible cause of the damage due to the location of the aircraft. I would be very interested in the cause as I have repaired dozens of these actuators over the years with no issues. I feel that the pilots unfamiliarity with the emergency operation of the landing gear extension system was a major factor in the cause of this incident.


Synopsis: A Mooney pilot reported a gear collapse on landing. The Mechanic that had previously repaired the landing gear system provided more details on the event.