Date: 201701
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: M-20 J (201) / Allegro
Operator: Personal
Operating under: Part 91
Mission: Personal
Flight phase: Landing
ATC / advisory: Tower ZZZ
Aircraft component: Landing Gear
Reporter organization: Personal
Reporter function: Pilot Not Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Commercial; Flight Crew Flight Instructor
Human factors: Distraction; Situational Awareness
Second reporter function: Pilot Flying
Anomaly: Ground Event / Encounter Gear Up Landing
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged
Contributing factors: Aircraft; Human Factors
Primary problem: Ambiguous

Narrative: After completion of 3 non eventful landings the PIC set up on final approach for the last landing of the day. Everything was going perfect as did the previous landings; however; this time I started to hear something scrape the runway as the plane settled onto the surface. We both saw smoke in the cockpit as we slid to a stop; the PIC pulled the gear lever back up due to seeing smoke coming from the gear handle. I saw smoke coming from the mixture knob and advised him to pull the mixture and secure the aircraft by turning everything off. I quickly exited the airplane and checked for leaks or signs of fire. Then returned to the cockpit to contact tower on the radio. So as an observer I would like to add I didn't not hear the gear warning horn or see the bypass light illuminated on the dash panel. I believe the PIC took all appropriate measures to ensure the gear was down and locked.


Second narrative: On our final traffic pattern; we were asked to extend our downwind leg due to two slower aircraft on final. The second aircraft told tower that they needed to slow down due to turbulent air. The tower then additionally asked us to square off our base and final approach. Wind conditions at the time were 270@11G16. Turning base to final; I believe that I extended the gear and put the flaps to 15. We then realized we were still too fast for the aircraft ahead of us; so we started making small S turns to increase the distance between our aircraft and the aircraft ahead of us. Neither my instructor nor I noticed a gear warning horn/gear bypass button flashing. During the previous hour; we had been performing commercial maneuvers during which the gear warning horn would be audible for several minutes at a time. Extended exposure to the gear warning horn desensitized our awareness of the alert. We also were distracted by complying with ATC instructions for an extended non-standard pattern and spacing. Additionally; after the aircraft in front of us landed; he required multiple taxi instructions from ATC to clear the active runway.At the time of touchdown; we were performing a short/soft field landing. It was not until we started hearing scraping that we realized something was wrong. We abruptly came to a stop; at which point both the instructor and myself noticed smoke coming through the instrument panel. I noticed smoke coming from the landing gear lever; and out of instinct; immediately threw it to the up position. The instructor occupying the right seat noticed smoke coming from the power quadrant. I then pulled the mixture to idle-cutoff. The CFI in the right seat then called tower and told them that we had landed without the landing gear extended. We then turned the avionics/master switch off and departed the aircraft.


Synopsis: Two Mooney pilots reported a gear up landing for unknown reasons.