# NTSB DEN90FA120: Cessna 170A, N3944V, Dillon, CO, June 3, 1990

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 2, 1990, 20:15 local (Jun 3, 1990, 02:15 UTC)
- Place: Dillon, CO
- Coordinates: 39.619781, -106.030418 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.6198&lon=-106.0304&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report September 5, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 17835
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN90FA120
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17835/pdf
- Page: https://openairdocs.org/ntsb/DEN90FA120

## Probable cause

IMPROPER PLANNING/DECISION BY THE PILOT, AND HIS FAILURE TO MAINTAIN AIRSPEED,  WHICH RESULTED IN AN INADVERTENT STALL.  FACTORS RELATED TO THE ACCIDENT WERE:  THE HIGH DENSITY ALTITUDE AND TERRAIN CONDITIONS.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of control - in flight, climb
  - procedures/directives - not followed, pilot in command
  - in-flight planning/decision - improper, pilot in command (cause)
  - weather condition - high density altitude (contributing factor)
  - terrain condition - mountainous/hilly (contributing factor)
  - terrain condition - blind/box canyon (contributing factor)
  - terrain condition - rising (contributing factor)
  - proper climb rate - not possible, pilot in command
  - airspeed - not maintained, pilot in command (cause)
  - stall - inadvertent, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - snow covered

## Analysis

THE PLT DEPD FM ALASKA SVRL DAYS BEFORE THE ACDNT & WAS EN ROUTE TO CANTON, OHIO. ON THE DAY OF THE ACDNT, HE TOOK OFF FROM MOAB, UTAH & WAS FLWG INTERSTATE 70 (A MAJOR HWY). THERE WERE WITNESSES NR THE EISENHOWER TUNNEL (EVEL 11,145 FT) AT THE CONTINENTAL DIVIDE IN COLORADO. THEY SAW AN ACFT THAT MATCHED THE DESCRIPTION OF N3944V. THEY RPRTD THE ACFT WAS EASTBOUND AT LOW ALT AS IT PASSED THE WEST ENTRANCE, THEN IT BEGAN CLIMBING. BEFORE REACHING THE DIVIDE, THE ACFT TURNEDABRUPTLY NORTH & WAS LAST SEEN FLYING UP A VALLEY. SUBSEQUENTLY, IT CRASHED ON A SNOW FIELD IN A BOWL AREA, SURROUNDED ON THE WEST, NORTH & EAST BY PEAKS & RIDGES. TERRAIN AROUND THE ACDNT SITE ROSE UPWARD TO 13,000 FT. THERE WAS EVIDENCE THE ACFT HAD IMPACTED IN A STEEP NOSE DOWN ATTITUDE. DURING IMPACT, THE LEADING EDGES OF THE WINGS WERE CRUSHED & THE EMPENNAGE HAD BROKEN ABOUT 4 FT AFT OF THE WINGS & HAD FOLDED AFT & RIGHT. THERE WAS EVIDENCE THE PLT HAD SURVIVED THE IMPACT, BUT DIED FROM COMPLICATIONS OF HYPOTHERMIA. HIS STUDENT PLT/MED CERT HAD BEEN ISSUED ON 4/24/86.

## Aircraft

- Registration: [N3944V](https://openairdocs.org/deregistered/N3944V-2012-11-14), registration cancelled 2012-11-14, S/N 18263, built 1948 (OpenAirDocs)
- Reported make and model: CESSNA 170A
- Registry model: [Cessna 170](https://openairdocs.org/model/cessna-170) (registry code 2072302) (OpenAirDocs)
- Registry engine: [Continental C145 series](https://openairdocs.org/engine/continental-c145-series) (registry code 17012, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 18263
- Engines: CONTINENTAL O-300 165 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Charles L. Guedel
- Airworthiness certificate: Standard, Normal
- Departed: CNY, MOAB, UT

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; medical: class 2, expired; seat: left; toxicology performed; flight hours: 315 total, 287 in this make and model, 259 as pilot in command, 28 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 200° at 20 knots
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 39 °F

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19900602018149A](https://openairdocs.org/incident/19900602018149A), Jun 2, 1990: Cessna 170A, Dillon, CO, Substantial damage, 1 fatal. Following I70,low AGL.road went through tunnel. Unable to outclimb terrain. Stalled,dived vertically into snowfield.

## Other investigations on N3944V (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB OAK69D0093](https://openairdocs.org/ntsb/OAK69D0093), Aug 18, 1968: Cessna 170 (N3944V), Vacaville, CA, substantial damage

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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