ANC18LA043 · Cessna 210 K
Cessna 210 K · Accident: landing gear collapse
From E80 · Belen, NM to Ramona Airport (RNM)
Event
- NTSB case
- ANC18LA043
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Cessna 210 K
- Aircraft type
- Cessna 210
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N9410M
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From E80 · Belen, NMTo Ramona Airport (RNM), Ramona, CA
- Aircraft age
- About 48 years (built 1970)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Landing · landing roll
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Landing gear collapse
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft systems
- Aircraft › Fluids/miscellaneous hardware
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The private pilot was conducting a personal, cross-country flight. He reported that he attempted to lower the retractable landing gear during a visual approach; however, the right main landing gear (MLG) did not fully extend. He attempted to manually pump the landing gear down with the emergency hand pump, but it was very difficult to move, and after several pumps, it would not move at all. Upon landing, the right MLG collapsed and the airplane impacted the ground, which resulted in substantial damage to the right horizontal stabilizer and elevator. Postaccident examination and tests revealed that, when the MLG system was tested using the airplane’s engine-driven hydraulic pump, fluid started leaking from a gap in the pump’s diaphragm seal between the front plate assembly and the rear housing assembly, and the MLG would not extend. Subsequently, the MLG system was tested with an external hydraulic pump, and it functioned properly. The two front plate cap screws on the side of the leaking pump gap were loose, had only three or four threads engaged with the rear assembly, and had insufficient shank length. The corresponding rear housing internal threads were sheared. Due to the installation of cap screws with insufficient shank length, fewer threads were engaged when the screws were tightened. The insufficient length of the shanks likely led to excessive force being applied on the engaged threads when the cap screws were installed, the threads being damaged, and a gap in the pump housing to develop, which allowed fluid to leak from the pump when it was pressurized. The hydraulic leak prevented the right MLG from fully extending and resulted in it collapsing upon landing.
Probable cause
The failure of the engine-driven hydraulic pump due to the installation of improper cap screws, which resulted in a gap in the pump housing, a subsequent hydraulic leak, and the landing gear collapsing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC18LA043
- Event ID
- 20180601X62529
- Case number
- ANC18LA043
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates, cause areas. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 30fc33f8f55818ef481aa471b6dc994f4edc709372c318025584d1034fd69c23; retrieved 2026-09-16T07:21:22.172Z.