Date: 201405
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: M-20 F Executive 21
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Landing
Airspace: Class E ZZZ
ATC / advisory: CTAF ZZZ
Aircraft component: Landing Gear
Component problem: Failed
Reporter organization: Personal
Reporter function: Single Pilot
Reporter qualification: Flight Crew Private
Anomaly: Aircraft Equipment Problem Critical; Ground Event / Encounter Ground Strike - Aircraft
Detector: Person Flight Crew
When detected: Other Landing
Result: Aircraft Aircraft Damaged; General Evacuated
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: I departed XXX RWY XX direct to XXX VFR.  Climb and cruise were uneventful as well as descent just west of XXXX; and set up for a right crosswind landing on RWY XX; announcing intentions. Having reviewed the descent checklist I then reviewed the prelanding checklist and put auxiliary fuel pump on; lowered manifold pressure to 12'; mixture full rich; prop full forward; and placed the Johnson bar into the down lock block with the familiar click into place and the attempted to pull it out without my thumb on the release button.  It did not budge. The green down indicator light came on.  At no time did the gear warning horn sound.  All circuit breakers were in.  I entered the pattern within a few feet of the published altitude and noted the speed reduced to 80 KIAS.  I turned to base and noted the PAPI was white/white; announcing position in the pattern.  I turned to final and crabbed to align with the centerline and then used aileron/rudder to side slip and maintain runway centerline.  I put in full flaps and retrimmed nose up and rechecked all instruments.  Speed now down to 69 KIAS; descent 400 FPM; Johnson bar in down lock; green light on; manifold pressure just above idle.  I flared just past the numbers using rudder/aileron to compensate for right crosswind and touched down right main then left main then lowered nose.  I realized something was wrong as I was sitting lower on the runway and skidding right with no more rudder control and that the prop turning pattern was altered with some smoke in front of the cowling.  I skidded to a stop and shut the engine and turned off master and closed the fuel flow.  I noted that the Jbar was now sitting about 4 inches up from the horizontal.  When I exited the aircraft unhurt other pilots immediately drove up to the runway to assist. I noted all 3 gears had collapsed; the prop had struck and runway and both blades were bent about 6 inches.  The airplane was able to be raised by two tow trucks and the gear lowered and locked again.  The airplane was able to be gently tugged back to tie down in wide arcs.  Observation of the downlock block a few days later with the plane on jacks and the gear cycled shows some wear in the receptacle and locking mechanism on the thumb latch release.  The gear circuit breaker had popped out.  A review of the current annual inspection does not reference the downlock block or preload and overcenter gear settings.  The annual was done by a mechanic who stated he had worked on a Mooney aircraft before. In retrospect; I would have had the annual done by a Mooney Certified Service Center and I would spend at least a few hours reviewing all systems and Mooney idiosyncrasies with the A&P.




Synopsis: The landing gear of a Mooney M20F collapsed/retracted during a normal landing. The reporter states that all checklists were followed and there appeared to be nothing out of the ordinary before touchdown.