NTSB Incident Report on the Olsen Pursuit at Fowler, CO (DEN90DTE04)

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NTSB Identification: DEN90DTE04
For details, refer to NTSB microfiche number 42459A

Accident occurred JUL-22-90 at FOWLER, CO
Aircraft: OLSEN PURSUIT, registration: N23GG
Injuries: 2 Fatal.

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.

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.