# NTSB DEN91LA069: Challenger II, N425DE, Silt, CO, May 9, 1991

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Limited investigation · Final report
- Date: May 9, 1991, 13:50 local (19:50 UTC)
- Place: Silt, CO
- Coordinates: 39.529678, -107.769119 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.5297&lon=-107.7691&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report May 5, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 18087
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN91LA069
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18087/pdf
- Page: https://openairdocs.org/ntsb/DEN91LA069

## Probable cause

AN IN FLIGHT ENCOUNTER WITH WIND CONDITIONS WHICH EXCEEDED THE AIRCRAFT PERFORMANCE CAPABILITY.  A FACTOR WAS:  THE PILOT'S FAILURE TO OBTAIN AVAILABLE EN ROUTE WEATHER INFORMATION.

## Sequence of events

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

- In flight encounter with weather, cruise
  - weather condition - high wind
  - meteorological service - not used, pilot in command (contributing factor)
- Loss of control - in flight, cruise
  - compensation for wind conditions - not possible, pilot in command
  - performance data - exceeded, pilot in command (cause)
- Altitude deviation,uncontrolled, descent - uncontrolled
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

WHILE CONDUCTING A 6 MILE FLIGHT FROM A PRIVATE AIRSTRIP TO A COUNTY AIRPORT, THE PILOT ENCOUNTERED IN FLIGHT WINDS WHICH EXCEEDED THE PERFORMANCE CAPABILITY OF THE AIRCRAFT. AIRCRAFT ALTITUDE CONTROL WAS NOT POSSIBLE AND THE AIRCRAFT IMPACTED THE GROUND IN UNCONTROLLED FLIGHT.

## Aircraft

- Registration: [N425DE](https://openairdocs.org/deregistered/N425DE-1991-10-03), registration cancelled 1991-10-03, S/N CH20589R0425 (OpenAirDocs)
- Reported make and model: CHALLENGER II
- Registry model: [Epperly Donald A CHALLENGER II](https://openairdocs.org/model/epperly-donald-a-challenger-ii) (registry code 05676KE) (OpenAirDocs)
- Category: Ultralight, amateur-built
- Serial number: CH20589R
- Engines: Bombardier 503 53 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Eppeepperly, Donald A.
- Registered owner: Eppeepperly, Donald A.
- Departed: SILT, CO
- Destination: RIL, RIFLE, CO

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 67; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; toxicology performed; flight hours: 40,000 total, 12 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 25 knots, gusting 45
- Visibility: 20 statute miles
- Lowest ceiling: 10,000 ft broken
- Temperature: 77 °F, dew point -0 °F
- Altimeter: 29.00 inHg
- Observed at: RIL, 3 nm away

## 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 19910509014899A](https://openairdocs.org/incident/19910509014899A), May 9, 1991: Amtrqc CHALLENGER2, Silt, CO, Destroyed, 1 fatal. Impacted near vertical between powerlines.

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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