Date: 201511
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 70
Light: Daylight
Aircraft: Cessna 210 Centurion / Turbo Centurion 210C; 210D
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Landing
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Gear Extend/Retract Mechanism
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Single Pilot; Pilot Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Commercial
Human factors: Training / Qualification; Confusion; Human-Machine Interface
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Excursion Runway
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Took Evasive Action; General Maintenance Action
Contributing factors: Aircraft; Procedure
Primary problem: Aircraft

Narrative: Planning a touch and go at my home airport Runway 22. Winds 260/4. Used 20 degree flaps since planning a touch and go. Touched down on center line; normal smooth landing. On landing; the plane seemed to be listing unusually to the left. I have 843 hours in this tail number; and likely as many landings; so I recognized the list immediately. And it started pulling to the left. Held off on adding power. As I slowed further; the plane started pulling harder left. Added power to see if I could get it back in the air; but it kept pulling left; so I quickly cut power as I headed off the side of the runway. I used full right yoke and right rudder to keep the left wing up; until I came to a stop in the dirt; upright. No injuries. ELT initiated on the final stop; so I turned it off; shut off the engine; and fuel. This was my first flight after getting the plane back from its annual inspection and some avionics installation (ADS-B out and in). So I was careful to take my time in the checklists. I distinctly remember completing the landing checklist; and seeing the green light for gear down. I also did not hear a gear warning when I pulled power to idle before touching down. On inspection; the left gear was folded under the aircraft. The main gear well doors were closed; so the left gear had collapsed onto the door. The gear left a visible trench in the dirt from the point it left the runway. The gear leg doors were open; however; and should have closed in a normal gear sequence. The landing gear hydraulic pack had been replaced with an overhauled unit 8 months prior; about 20 hours earlier. While this was my first flight after the annual inspection; the maintenance shop had flown it to a nearby maintenance facility and back for the avionics work; after the annual; so it had at least 2 landings on it since the annual. My lesson learned was to not just trust the green gear light - had I checked the gear mirror I had installed on the right wing; perhaps I would have seen the gear leg doors were still open; hinting that the gear down sequence had not completed. And maybe I would have looked at the gear on the left side for longer; making sure it was fully extended - I believe I gave it the normal glance; but don't distinctly recall how it appeared (e.g.; was it that landing or one of the many prior landings that I am recalling).




Synopsis: A C-210's left landing gear collapsed on landing after it apparently had not fully extended without any failure indication. The hydraulic pack had been replaced recently and this was the first flight flown following an annual.