WPR20LA177 · Zenair CH601
Zenair CH601 · Accident: controlled flight into terrain/object (CFIT) on approach
From Phoenix Deer Valley Airport (DVT) to Ak-Chin Regional Airport (A39)
Event
- NTSB case
- WPR20LA177
- 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
- 1 · 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
Zenair CH601
- Aircraft type
- Zenair CH601
- 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
- N6402X
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Phoenix Deer Valley Airport (DVT), Phoenix, AZTo Ak-Chin Regional Airport (A39), Maricopa, AZ
- Aircraft age
- About 18 years (built 2002)
- 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
- Approach · VFR pattern base
- 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
- Controlled flight into terrain/object (CFIT)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Personnel issues › Psychological
Approximate · Coordinates from the NTSB case API, not marked as estimated; no uncertainty radius is established.
NTSB narrative
The pilot departed from his home airport for a night flight to an airport he had flown to in the past. The flight was in trail with another airplane as they approached the airport from the north. Flight track data indicated that the accident airplane overflew the airport midfield about 300 ft below the traffic pattern altitude. The flight progressed well beyond the airport environment and descended to about 600 ft below the traffic pattern altitude. As the airplane began what appeared to be an extended base turn to the southeast, about 2 miles from the runway threshold, it struck an isolated and unlit hill just below its summit.
Examination of the wreckage did not reveal any mechanical anomalies with the airplane or engine, and damage signatures to the propeller indicated that the engine was producing power at impact.
Based on autopsy findings, the pilot had mild-to-moderate atherosclerosis in his coronary arteries. While the atherosclerosis placed the pilot at some increased risk for an acute cardiac event, there was no evidence to suggest such an event occurred and, given the pilot was communicating with air traffic control and the other airplane right up until the accident, the pilot’s cardiovascular disease was not a factor. Given the operational issued of the accident, the ethanol concentrations identified in liver tissue were from sources other than ingestion.
At the time of the accident, the sun had set, but there was still light on the horizon, toward the direction the airplane was heading prior to turning toward the airport. The light conditions would have provided a challenging perceptual environment for the pilot as he looked toward the unlit terrain and peak. It was likely that the pilot’s visual attention was directed toward the airport at that time, while he monitored the other airplane and positioned himself for landing. Both factors would have impeded the pilot’s visual identification of the terrain. Further, the limited cultural lighting in the vicinity of the airport would provide few cues from which the pilot could reliably estimate distance while maneuvering. The reason for the pilot’s nonstandard flight track and flight below pattern altitude is unknown, but it is indicative of the pilot losing situational awareness as he followed the other airplane in the traffic pattern and prepared for landing over unlit and unpopulated terrain.
Probable cause
The pilot’s loss of situational awareness and descent below pattern altitude during the landing approach, which resulted in collision with terrain at night.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR20LA177
- Event ID
- 20200610X23504
- Case number
- WPR20LA177
- 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: local date, investigation status, coordinates, cause areas. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2020-06-10.
- API snapshot SHA-256: ed3cd90126e0b540113b1c4b33e28cc39da8b9ff26da8afb1c51808dd3d70a61; retrieved 2026-09-15T07:16:05.678Z.