CEN21LA067 · Vans RV4
Vans RV4 · Accident: loss of control in flight on approach
From Durango La Plata County Airport (DRO) to Telluride Regional Airport (TEX)
Event
- NTSB case
- CEN21LA067
- 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
- 2 · 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
Vans RV4
- Aircraft type
- Vans RV4
- 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
- N87LW
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Durango La Plata County Airport (DRO), Durango, COTo Telluride Regional Airport (TEX), Telluride, CO
- Aircraft age
- About 33 years (built 1987)
- 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
- Loss of control in flight
- 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 oper/perf/capability
- Personnel issues › Task performance
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 and passenger were concluding a cross-country flight and were flying in the traffic pattern at their intended destination when the airplane pitched nose down and descended rapidly into mountainous terrain during the turn from the base leg to final approach.
There were multiple witnesses who reported seeing the airplane enter a steep left turn toward the airport followed by a nose-down descent toward terrain. One witness reported that the airplane completed 3 or 4 spins while it descended nose down in a vertical descent and that the sound of the engine was “quite loud.” Airport security camera footage showed the airplane in a left-wing down, nose down, descending turn into terrain east of the airport.
According to automatic dependent surveillance-broadcast (ADS-B) data, shortly after the airplane entered the left turn from the base leg to final approach, the airplane decelerated to 50 knots calibrated airspeed (KCAS) and the descent rate increased from 600 to 3,850 ft/min. According to the airplane kit manufacturer, the airplane’s wings-level aerodynamic stall speed at a maximum gross weight was 47 KCAS. The airplane maneuvering in the traffic pattern would require turns and, as such, there was a corresponding increase to aerodynamic stall speed during the turns. Additionally, the airplane’s left-wing-down roll was increasing when the airplane entered the rapid descent.
Postaccident examination revealed no evidence of a preexisting mechanical malfunction or failure that would have precluded normal operation of the airplane.
Based on the surveillance video footage, witness accounts, and the recorded ADS-B data, it is likely the pilot did not maintain adequate airspeed during the left turn from the base leg to final approach, which resulted in the airplane exceeding its critical angle of attack and inadvertently entering an aerodynamic stall/spin at a low altitude over mountainous terrain.
Toxicology testing detected morphine in the pilot’s urine but not in his blood. The detection of acetaminophen suggests that the pilot had taken codeine with acetaminophen for mild to moderate pain relief. Since no morphine was present in the blood, no impairing effects would be expected. Thus, the effect of the pilot’s use of morphine or opiate pain reliever was not a factor in this accident.
Probable cause
The pilot’s failure to maintain adequate airspeed during the turn from the base leg to final approach, which resulted in the airplane exceeding its critical angle of attack and entering an inadvertent aerodynamic stall/spin at a low altitude over mountainous terrain.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN21LA067
- Event ID
- 20201127102340
- Case number
- CEN21LA067
- 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: 79f5ac3be5bc8b16c46b2fce068ad4b779d034ce005b61d8bca1cd90ed71f70c; retrieved 2026-09-15T07:23:03.162Z.