FLIGHT FINDINGSAVIATION OCCURRENCE MAP
Back to map

DEN92FA020 · Grumman American AA-5A

25 Dec 1991 · Monte Vista, CO, United States

Grumman American AA-5A · Accident: loss of control in flight during initial climb

Report a problem

Event

NTSB case
DEN92FA020
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
3 · all aircraft and ground
Ground fatalities
0
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

Grumman American AA-5A

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
N9991U
Onboard fatalities
Unknown
Route
From not recordedTo not recorded
Aircraft age
Not recorded
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
Initial climb
First occurrenceThe 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
Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
Stall
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Destroyed

Cause areas

  • Pilot in command › Stall, inadvertent

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

WHILE ON A POST TAKEOFF CROSSWIND CLIMB, THE PILOT INADVERTENTLY STALLED THE AIRCRAFT AT A LOW ALTITUDE. THE AIRCRAFT IMPACTED VERTICALLY IN A FROZEN OPEN FIELD. INVESTIGATION REVEALED THE AIRCRAFT TO BE 90 POUNDS OVER MAXIMUM GROSS WEIGHT; THE PILOT TO BE SUFFERING FROM PHYSICAL IMPAIRMENT DUE TO CARBON MONOXIDE POISONING; THE PILOT TO BE LOW IN TOTAL EXPERIENCE, EXPERIENCE IN TYPE; AND RECENT EXPERIENCE. TOXICOLOGY TESTS REVEALED 16% CARBOXYHEMOGLOBIN IN THE PILOT'S BLOOD. PASSENGER TEST RESULTS WERE NEGATIVE. THAT SATURATION LEVEL CAN CAUSE DEGRADATION IN JUDGMENT AND PERFORMANCE. THE PILOT WAS A MECHANIC AND HAD BEEN EXPOSED TO RUNNING ENGINES IN A NON-VENTILATED SHOP THE DAY/EVENING PRIOR TO THE ACCIDENT.

Probable cause

AN INADVERTENT STALL BY THE PILOT IN COMMAND AT AN ALTITUDE INSUFFICIENT TO EFFECT RECOVERY. FACTORS WERE: AIRCRAFT GROSS WEIGHT ABOVE MAXIMUM; PHYSICAL IMPAIRMENT OF THE PILOT; LACK OF TOTAL EXPERIENCE; LACK OF RECENT EXPERIENCE; AND LACK OF EXPERIENCE IN TYPE.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record DEN92FA020
Event ID
20001212X18582
Case number
DEN92FA020
Dataset
historical-pre2008
Source SHA-256
89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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. 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: 8a9889adec06f0cdc85e45903fa12f8bac70654250ddca522102610c44cdb370; retrieved 2026-09-21T01:26:15.202Z.