WPR17LA131 · Cessna 421B B
Cessna 421B B · Accident: landing gear collapse
From French Valley Airport (F70) to McClellan-Palomar Airport (CRQ)
Event
- NTSB case
- WPR17LA131
- 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 421B B
- Aircraft type
- Cessna 421
- 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
- N380AL
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From French Valley Airport (F70), Temecula, CATo McClellan-Palomar Airport (CRQ), Carlsbad, CA
- Aircraft age
- About 45 years (built 1972)
- 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
- Not determined › Not determined
Approximate · Coordinates from the NTSB case API, not marked as estimated; no uncertainty radius is established.
NTSB narrative
The pilot reported that touchdown on the runway and rollout were normal but that the airplane began to wobble as it decelerated to about 10 to 15 mph. He maintained directional control without braking. However, the wobble worsened, and the right main landing gear collapsed, which resulted in substantial damage to the right wing. Postaccident examination of the airplane revealed that the right main landing gear torque link pivot bolt assembly was severed, and the two inboard spacer washers, nut, and cotter pin were not located. Additionally, the the landing gear trunnion was partially separated from the wing structure. Vertical scuffing was observed on the outboard crown of the right main landing gear tire, which is consistent with the wheel skidding along the ground after becoming misaligned about 90° from normal. Metallurgical examination of the torque link pivot bolt revealed that the bolt fractured through the threaded region at the edge of the pivot barrel in bending overstress, with no evidence of preexisting cracking or corrosion. In addition, the trunnion fractured in overstress, with no evidence of preexisting fatigue cracks or fractures. Alignment of the wheel is achieved by washers installed between the upper and lower torque link assemblies; disconnection of the upper and lower torque link assemblies from one another could result in wheel misalignment, vibration, and ultimately failure of the main landing gear. However, due to postaccident damage to the landing gear and the unrecovered components, there was insufficient evidence available to determine why the right main landing gear collapsed.
Probable cause
The right main landing gear collapse for undetermined reasons.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR17LA131
- Event ID
- 20170622X75754
- Case number
- WPR17LA131
- 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. 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: 528f3964ecba9a060ff939c18460576b311f84a8a7369d69f76fb74d2ca46dcd; retrieved 2026-09-16T05:26:43.541Z.