N2122S

On January 2, 2018, about 0920 Pacific standard time, a Cessna T210L airplane, N2122S, was substantially damaged during landing following a right main landing gear collapse at Aurora State Airport (UAO), Aurora, Oregon. The private pilot was not injured. The airplane was registered to and operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed at the time of the accident and no flight plan was filed. The cross-country flight originated from Paine Field (PAE), Everett, Washington, about 0758, and was destined for Aurora. In a report submitted to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot reported that while on downwind for runway 35 at UAO, he activated the landing gear extension lever, which was followed by the orange light going out, however, the green [down and locked] light did not illuminate. The pilot further reported that the gear appeared to be down. He then requested permission to perform a control tower fly-by, so the controller could observe the position of the landing gear; the controller confirmed that the landing gear appeared to be down, followed by clearing the pilot for a left downwind approach and landing. The pilot stated that while on downwind he attempted to raise and lower the landing gear, however, while the orange light would illuminate, the green light would not. The pilot opined that the gear appeared to be down as viewed from the airplane's landing gear mirror. Shortly after touchdown the right main landing gear collapsed, which was followed by the airplane swerving right and into the runway safety area. The airplane came to rest on its left main landing gear, nose gear and right wing tip. The right horizontal stabilizer and elevator sustained substantial damage. The pilot also mentioned that he forgot to perform the alternate landing gear extension procedure prior to landing.

Under the supervision of a Federal Aviation Administration aviation safety inspector, a postaccident examination of the landing gear system was performed on January 8, 2018, at the facilities of Willamette Aviation, Aurora State Airport, Aurora, Oregon. The results of the examination revealed the following:

The landing gear hydraulic lines, electrical wires, actuators, locks, valves and other landing gear system components were visually inspected, with no anomalies noted.

The hydraulic system fluid was visually inspected, with the level of the fluid above the ADD mark as indicated on the reservoir dip stick. There were no obvious hydraulic leaks observed from any specific hydraulic component.

The landing gear switch handle was in the GEAR DOWN position, and all three landing gear were visually and physically confirmed to be in the DOWN and LOCKED positions. The landing gear down lock actuators were both extended, and the locks themselves were over the lock pins in a position appropriate to "locked" in the down position, and with visually confirmed engagement.

With the airplane position on the ground and resting on its landing gear, the green GEAR DOWN indicator illuminated when the master switch was positioned to ON; the hydraulic power pack ran for about one (1) second before the light came on.

The airplane was jacked using tripod jacks, wing-mounted jack adapters, and a weighted tail stand. The landing gear was retracted and extended eight (8) cycles over a period of about 40 minutes, and functioned as described in the Cessna T210L maintenance manual, with positive down lock engagement. A green GEAR DOWN light indication was followed by the hydraulic pump shutting off. Both retraction and extension cycles were completed in approximately eight (8) seconds. Each of the cycles resulted in a normal gear retraction and extension cycle completion, with only slight increases in cycle times when the landing gear was de-synchronized by application of resistance to one or the other gear legs. The landing gear warning horn system was tested for proper operation, with no anomalies noted during the functionality check. All systems operated normally. The examination revealed no evidence of what precipitated the collapse of the right main landing gear during the landing roll. (For an in-depth description of the examination and testing, refer to the Aircraft and Landing Gear System Inspection/Function Report, which is appended to the docket for this report.)