Sequence of Events
The pilot reported that he moved the landing gear handle to the down position while crossing over the field to enter the downwind leg of the traffic pattern for runway 20. At that time, he noticed that the green landing gear annunciator light had illuminated. Due to the high level of traffic in the pattern, the pilot did not look into the mirrors to visually check whether the landing gear had deployed successfully, which he usually does.
During the landing flare, the airplane's tail impacted the runway, causing the airplane to bounce. The tail came down and struck the runway again. Shortly thereafter, the entire airplane spun off the runway to the left, coming to rest on the grass separating the taxiway and the runway.
Post-Accident Examination
A Federal Aviation Administration (FAA) inspector examined the airplane after the accident. He stated that the main landing gear doors were closed, and the main gear was in the fully retracted position. The nose wheel had partially extended.
The FAA inspector interviewed several witnesses who reported hearing the airplane's engine increase in power just prior to the landing.
Landing Gear System Description
According to the Cessna 210 Owners Manual, the landing gear and doors operate in a specific sequence. When the pilot moves the gear position handle out of the neutral position, the engine-driven hydraulic pump begins to create hydraulic pressure and transfers it to the hydraulic actuators, which operate the landing gear doors and landing gear. When the gear position handle is placed in the down position, the hydraulic pump supplies pressure to the door actuators first, allowing the doors to open. Then, the hydraulic pressure switches to the landing gear actuators, and the gear extends. Once the landing gear has completed extension, the hydraulic pressure switches back to the door actuators, and the doors close. When the doors have completely closed, the gear position handle returns to the neutral position, completing the process.