WPR18LA129 · Gulfstream AM Corp Comm DIV 695A A
Gulfstream AM Corp Comm DIV 695A A · Accident: landing gear collapse
From Chino Airport (CNO) to Eastern Sierra Regional Airport (BIH)
Event
- NTSB case
- WPR18LA129
- 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
Gulfstream AM Corp Comm DIV 695A A
- Aircraft type
- Gulfstream Am Corp Comm Div 695
- 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
- N79PH
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Chino Airport (CNO), Chino, CATo Eastern Sierra Regional Airport (BIH), Bishop, CA
- Aircraft age
- About 36 years (built 1982)
- 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
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot reported that before touching down on the runway with a 13-kt 50° right crosswind, the landing gear were down with the three green landing gear lights illuminated. After touching down and beginning the ground roll, the airplane pulled slightly to the left, the left wing dropped, and the airplane started to pull harder to the left. The pilot corrected with right rudder and brake, as well as reverse power on the right engine. The left wing dropped further, and the airplane pulled harder to the left before coming to rest about 10 ft from the left edge of the runway. The left main landing gear had collapsed, which resulted in substantial damage to the fuselage.
Postaccident examination revealed that the left main landing gear upper arm forging failed from fatigue cracking. The largest fatigue crack appeared to have initiated along multiple sites along scratch-like features on the outside surface of the arm. These cracks grew inward under spectrum loads until the loads from the accident landing could not be withstood by the remaining cross section, causing the part to fracture in overstress.
Probable cause
The failure of the left main landing gear upper arm forging due to fatigue cracking and subsequent overstress, which resulted in the collapse of the landing gear during the landing roll.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR18LA129
- Event ID
- 20180427X31921
- Case number
- WPR18LA129
- 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, 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: fd64e45e3303db706f80cd6429a9514d25aaf612b5b4c1aa0ea462b0f733317f; retrieved 2026-09-16T06:57:55.928Z.