Date: 202005
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: Turbulence; 10
Light: Daylight
Aircraft: M-20 E Super 21
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Mission: Personal
Flight phase: Landing
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Landing Gear
Component problem: Failed
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Anomaly: Aircraft Equipment Problem Less Severe; Ground Event / Encounter Ground Strike - Aircraft; Ground Event / Encounter Loss Of Aircraft Control; Ground Incursion Runway
Detector: Person Flight Crew
When detected: Other landing
Result: Air Traffic Control Provided Assistance; Aircraft Aircraft Damaged; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: When touching down; the left side felt wobbly. The right landing gear had already touched down. The left landing gear was either not out (and I was just rolling on the right gear); or it was out but was toed to the inside; not carrying any weight. The left side was now pushing forward; turning the plane to the right. If the left landing gear was not extracted; this was most likely due to less drag on the left side and me braking (with brake effectiveness only on the right side); and if it was extracted; most likely a wind gust. I steered against that; to the left; so that I could stay on/near centerline. After a few seconds I heard a loud bang. I continued to try to keep the plane in the middle; but after a few seconds I briefly looked left and saw my wing on the asphalt. Now I knew that the left landing gear had collapsed. I continued trying to keep the plane in the middle; but the pull to the left was too strong to keep it on centerline. I still had some rudder/foot pedal authority so as to be able to get the plane off the runway just between two runway edge lights; so as to not get a prop strike (possibly causing engine problems; perhaps up to engine fire?). The plane kept turning left and 'swept' around; leaving about 2 ft. of the left wing still on the runway. The right landing gear and the nose landing gear were extracted and carried weight; only the left landing gear had collapsed.No injuries; no fire; no engine damage; no fuel leak. I did my radio transmissions; but then left the plane for reasons of safety. The bottom antenna must also be crushed; but it was still working; because I made my emergency call to the Tower on the number two radio; which uses the bottom antenna. So it was still working; even though it's probably totally crushed.It was only the second flight after the plane had a fresh annual. After the annual the mechanic told me that he had to rerig the landing gear it was 'very bad'. He even apologized for having had to charge me four hours for that. He made a specific point about rerigging the landing gear because it was so bad. I think it is very likely that it was just fine before. I had flown with the previous landing gear rigging since 2016. And I bought the plane in 1999 and know what the Johnson bar strength feels like. In over twenty years I have developed a solid feeling for the landing gear spring strength when you use the Johnston bar to get the gear in and out. During the two take-offs since the rerigging; using the Johnson bar felt super-soft; almost as if it fell in my lap. So; the springs were extremely loose. I believed the mechanic; thinking I had bad rigging for some twenty years and trusted him. I felt bad for having done something 'wrong' for twenty years. After the first landing with the new rigging I even discussed it with him by chat; and I could always provide that transcript. I find it curious that he asked me to keep him abreast and tell him how things 'were going' with the new landing gear rigging that he gave me. 'Keep me posted'. Again; I trusted the mechanic I believed the new rigging was right and I did it 'wrong' for some twenty years. By now I have to assume HE actually messed up the landing gear rigging; I had it right for twenty years; and HE did it wrong during the last annual. The plane will soon be ferried to a Mooney specialist facility; where they will look at it. They say they can assess the rigging only once they have it in their possession and up on jacks. Before that they cannot comment on the rigging. I have waited nine days before filing this report; hoping I could include any information about his finding. Unfortunately I cannot wait any longer; I only have ten days for the report; and the plane is not even ferried to him yet. So I can't provide any info about the rigging at this time.

Callback: Reporter stated that he is awaiting a ferry permit in order to relocate the aircraft to the service center for assessment.



Synopsis: M20 Pilot reported landing gear had recently been re-rigged during annual inspection and during landing left main gear collapsed.