# Accident 19980705015949A: Amrgen AA1A, Larkspur, CO, July 5, 1998

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: July 5, 1998, 11:24 local time
- Place: Larkspur, CO
- Damage: Destroyed
- Phase of flight: Normal Cruise
- Operating rules: General operating rules (Part 91)
- Location: 39.1806° N, 104.8899° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=39.1806&lon=-104.8899&mi=10
- Aircraft: N9453L, a cancelled registration (https://openairdocs.org/deregistered/N9453L-2001-05-09) (OpenAirDocs)
- Registry model: American AA-1A (registry code 0630710, https://openairdocs.org/model/american-aa-1a) (OpenAirDocs)
- Reported make and model: AMRGEN AA1A
- Reported engine: LYC O235C2C
- People aboard: 1
- Fatal injuries: 1
- Pilot flight hours: 267 total, 130 in this make and model, 65 in the last 90 days
- NTSB investigation: [NTSB FTW98FA299](https://openairdocs.org/ntsb/FTW98FA299) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19980705015949A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

(.4)THE 265-HOUR PRIVATE PILOT FILED A VFR FLIGHT PLAN FROM BOULDER, COLORADO, TO PUEBLO, COLORADO, AND REQUESTED VFR FLIGHT FOLLOWING SERVICES. THIRTY MINUTES LATER, THE PILOT REPORTED HE WAS ENCOUNTERING 'MODERATE TURBULENCE,' THEN 'QUITE A BIT OF TURBULENCE,' THAT HE WAS TURNING AROUND, AND REQUESTED FLIGHT FOLLOWING SERVICES BACK TO BOULDER. SHORTLY THEREAFTER, THE PILOT ADVISED HE WAS IN A SPIN AND UNABLE TO CORRECT AND THAT HE WAS TURNING OFF HIS TRANSPONDER.  THE AIRPLANE STRUCK THE GROUND IN A NEAR-VERTICAL ATTITUDE.  THERE WAS NO EVIDENCE OF A SPIN.  HIS LOGBOOK INDICATED HE HAD NEVER BEEN DEMONSTRATED A SPIN OR HAD BEEN GIVEN SPIN INSTRUCTION.  THE PILOT'S OPERATING HANDBOOK PROHIBITS SPINS AND STATES:  'THERE IS EVIDENCE THAT PERMITTING A SPIN TO GO BEYOND ONE TURN WITHOUT INITIATING PROPER RECOVERY PROCEDURES CAN ALLOW A SPIN MODE TO DEVELOP FROM WHICH RECOVERY IS NOT POSSIBLE.'                                                                       (-23)ALFRED PURDON DEPARTED BOULDER, CO AS PILOT IN COMMAND OF N9453L, A GRUMMAN AAIA TRAINER ON 7/5/98.  A STANDARD WEATHER BRIEFING WAS OBTAINED FROM DENVER FLIGHT SERVICE AND A VFR FLIGHT PLAN WAS FILED.  VISUAL METEOROLOG ICAL CONDITIONS PREVAILED, WITH NO SIGNIFICANT HAZARDOUS WEATHER REPORTED OR FORECAST. WHILE ENROUTE TO PUEBLO, CO APPROXIMATELY 5 MILES S.E. OF CASTLE ROCK, CO.  THE PILOT RADIOED DENVER TRACON TWICE THAT HE WAS EXPERIENCING MODERATE TURBULENCE.  A THIRD TRANSMISSION WAS RECEIVED IN WHICH THE PILOT STATED HE WAS IN A SPIN, UNABLE TO CORRECT AND TURNING OFF HIS TRANSPONDER.  RADAR CONTACT WAS LOST AT 1724Z.  THE PILOT, SOLE OCCUPANT OF THE AIRCRAFT SUSTAINED FATAL INJURIES AND THE AIRCRAFT WAS DESTROYED.

## The NTSB's investigation of this event (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 FTW98FA299](https://openairdocs.org/ntsb/FTW98FA299), Jul 5, 1998: Grumman American AA-1A (N9453L), Larkspur, CO, destroyed, 1 fatal. Probable cause: The pilot inadvertently stalling the airplane and entering an unrecoverable spin. A factor was clear air turbulence.

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.