WPR22LA035 · Sonex WAIEX B
Air-Spaces Sonex WAIEX B · Accident: loss of engine power (partial) en route
From Glendale Municipal Airport (GEU) to an unrecorded destination
Event
- NTSB case
- WPR22LA035
- 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
- Event fatalities
- Unknown
- 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
Sonex WAIEX B
- Aircraft type
- Sonex WAIEX
- 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
- N535D
- Operator
- Air-Spaces
- Onboard fatalities
- Unknown
- Route
- From Glendale Municipal Airport (GEU), Glendale, AZTo not recorded
- Aircraft age
- About 3 years (built 2018)
- 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
- En route
- 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
- Loss of engine power (partial)
- 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 power plant
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The pilot reported the engine began running rough during cruise flight, and the airplane could not maintain altitude. The pilot initiated a forced landing to an airstrip and during the descent realized that he was not going to make the airstrip, so he elected to landed on the desert terrain. The airplane impacted rocks and a barbed wire fence which caused the airplane to nose over, which resulted in substantial damage to the wings, stabilizers, and ruddervators. Postaccident examination of the engine revealed that the No. 4 exhaust rocker assembly swivel housing separated from the screw body, likely due to wear of the swivel and the swivel pad housing. This wear likely occurred because of either incorrect spacing between the pad and valve, or corrosion.
Probable cause
Failure of the rocker swivel assembly due to either wear or corrosion, which resulted in a loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR22LA035
- Event ID
- 20211115104244
- Case number
- WPR22LA035
- 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: 0504e12894becfc4901836cab50423ce243f35aa6b5dde81a82fb71738692b2b; retrieved 2026-09-16T14:44:36.348Z.