# NTSB DEN90DTE04: Olsen Pursuit, N23GG, Fowler, CO, July 23, 1990

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: July 22, 1990, 19:05 local (Jul 23, 1990, 01:05 UTC)
- Place: Fowler, CO
- Coordinates: 38.119316, -104.019401 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.1193&lon=-104.0194&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 17796
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN90DTE04
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17796/pdf
- Page: https://openairdocs.org/ntsb/DEN90DTE04

## Probable cause

FAILURE OF THE PILOT TO MAINTAIN ADEQUATE AIRSPEED ON FINAL APPROACH TO LAND, WHICH RESULTED IN AN INADVERTENT STALL. A FACTOR RELATE TO THE ACCIDENT WAS: THE PILOT'S PHYSICAL IMPAIRMENT FROM CARBON MONOXIDE.

## Sequence of events

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

- Loss of control - in flight, approach - vfr pattern - final approach
  - airspeed - not maintained, pilot in command (cause)
  - stall - inadvertent, pilot in command (cause)
  - physical impairment(carbon monoxide), pilot in command (contributing factor)
  - physical impairment(carbon monoxide), passenger
  - impairment(drugs), pilot in command
  - impairment(drugs), passenger
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

WHILE ON A LOCAL FLT, THE ACFT IMPACTED THE GND ABOUT 3/10 OF A MILE SHORT OF RWY 4.  THERE WERE NO KNOWN WITNESS TO THE ACDNT, THOUGH ONE PERSON SAW DUST FROM THE ACDNT SITE & WENT TO INVESTIGATE.  THE AIRCRAFT CAME TO REST ON ITS BELLY & BURNED.  THERE WAS EVIDENCE THAT THE ACFT HAD IMPACTED IN A LEVEL ATTITUDE, BUT THERE WAS NO APPARENT FORWARD MOVEMENT OF THE ACFT AFTER PRINCIPAL IMPACT.  NO PREIMPACT PART FAILURE OR MALFUNCTION OF THE ACFT OR ENG WAS FOUND DURING THE INVESTIGATION.  TOXICOLOGY EXAMS OF THE PLT'S & PSGR'S BLOOD SHOWED A CARBOXYHEMOGLOGIN (CARBON MONOXIDE) SATURATION OF 19% &  16%, RESPECTIVELY.  THE TOXICOLOGIST NOTED THAT SMOKERS WOULD BE EXPECTED TO HAVE A SATURATION LEVEL OF 3% TO 10%.  ALSO, METABOLITES OF MARIJUANA (CARBOXYLE ACID) WERE FND IN THE PLT'S & PSGR'S BLOOD AT LOW LEVELS OF 9 & 7 NG/ML, RESPECTIVELY.  THE SPECIFIC SOURCE OF CARBON MONOXIDE WAS NOT DETERMINED.

## Aircraft

- Registration: [N23GG](https://openairdocs.org/deregistered/N23GG-1994-01-03), registration cancelled 1994-01-03, S/N 9123 (OpenAirDocs)
- Reported make and model: OLSEN PURSUIT
- Registry model: [Olsen Gordon L PURSUIT](https://openairdocs.org/model/olsen-gordon-l-pursuit) (registry code 056125L) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 9123
- Airframe hours: 93
- Engines: LYCOMING O-320-E2C 150 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Registered owner: Phillip W. Switzer
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Unknown, July 11, 1990
- Departed: 09V
- Airport: 09V, Fowler, runway 4, 3,400 × 75 ft, dirt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 35; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: right; toxicology performed; flight hours: 305 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 100° at 10 knots
- Visibility: 40 statute miles
- Temperature: 70 °F, dew point 57 °F
- Altimeter: 30.00 inHg
- Observed at: LHX, 30 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 19900722027559A](https://openairdocs.org/incident/19900722027559A), Jul 22, 1990: Amtr PURSUIT, Fowler, CO, Destroyed, 2 fatal. Vertical crash near runway. Test showed both victims unconscious at impact from high level of carboxyhemoglobin.

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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