Accident
On August 21, 2023, at 1210 Pacific daylight time, a Cessna T210, N6535B, was substantially damaged in an accident near Napa, California. The airplane was operated as a personal flight under Title 14 Code of Federal Regulation Part 91. The pilot, a pilot-rated passenger, and a passenger were not injured.
According to the pilot, she was repositioning the airplane to Modesto, California, for an annual inspection. After takeoff from Napa County Airport (APC), while climbing to about 3,500 ft mean sea level, the airplane sustained a total electrical failure. The pilot decided to return to APC.
Before landing, the landing gear would not extend normally due to the loss of electrical power, so the pilot performed a manual gear extension. She stated that she followed the pilot operating handbook emergency procedures, pumping the manual gear extension lever up and down more than 55 times and feeling significant resistance. Partial electrical power was restored to one radio, allowing communication with air traffic control. The pilot flew a visual approach to runway 19R. During the turn to base leg, the tower controller reported that the gear appeared to be down. On landing, both main landing gear collapsed, causing the airplane to skid off the right side of the runway, strike brush, and substantially damage the right wing and right horizontal stabilizer.
Aircraft and Systems
The Cessna T210's landing gear system, as described in the pilot operating handbook, uses hydraulic actuators powered by an electrically driven hydraulic power pack housed within the control pedestal. The power pack is activated by the landing gear lever and deactivated by a pressure switch. Two-position indicator lights show gear position. The system also includes a nose gear safety switch, an emergency extension hand pump, and a gear-up warning system.
The Landing Gear Fails to Extend checklist directs the pilot to pump the emergency hand pump "until resistance becomes heavy - about 65 cycles," with a note that it takes about 55 cycles (110 strokes) to extend the gear and about 10 more to close the gear doors.
Post-Accident
The airplane owner did not respond to requests from investigators to examine the wreckage. He did not submit the National Transportation Safety Board Pilot/Operator Aircraft Accident/Incident Report Form 6120.1 nor produce the airplane's logbooks. The owner disposed of the airplane before an examination could be completed, so the electrical and landing gear systems were not examined.