# NTSB DEN91LA040: Aerostar RX7, N35773, Durango, CO, February 2, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: February 2, 1991, 09:30 local (16:30 UTC)
- Place: Durango, CO
- Coordinates: 37.270305, -107.879493 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.2703&lon=-107.8795&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report May 5, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 18070
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN91LA040
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18070/pdf
- Page: https://openairdocs.org/ntsb/DEN91LA040

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN OBSTACLE CLEARANCE.  FACTORS WERE:  THE UNFAVORABLE WINDS AND THE HIGH OBSTRUCTIONS IN THE FLIGHT PATH.

## Analysis

AFTER LIFTING THE BALLOON OUT OF THE CANYON, THE PILOT BEGAN LOOKING FOR A LANDING SITE IN THE FLATS ABOVE THE CANYON RIM.  THE BALLOON BEGAN TO DESCEND AND DESPITE A LONG BURN, THE DESCENT CONTINUED.  IN AN EFFORT TO MISS THE POWER LINES, THE PILOT RIPPED OUT THE TOP BUT WAS UNABLE TO AVOID THE COLLISION.  THE PILOT CONCLUDED THAT HE ENCOUNTERED A ROTOR GENERATED BY WINDS IN THE CANYON FORCING THE BALLOON TO THE GROUND. HE ALSO STATED THAT THE WIRES HAD BEEN VISIBLE FOR AN 'EXTENDED PERIOD OF TIME.'

## Sequence of events

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

- In flight encounter with weather, cruise - normal
  - weather condition - unfavorable wind (contributing factor)
- Forced landing, descent - uncontrolled
  - terrain condition - high obstruction(s) (contributing factor)
  - clearance - not maintained, pilot in command (cause)
  - object - wire,transmission(marked)

## Aircraft

- Registration: [N35773](https://openairdocs.org/deregistered/N35773-2002-05-22), registration cancelled 2002-05-22, S/N RX7-3208, built 1989 (OpenAirDocs)
- Reported make and model: Aerostar RX7
- Registry model: [Raven Industries RALLY RX7](https://openairdocs.org/model/raven-industries-rally-rx7) (registry code 7480503) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Balloon
- Serial number: RX7-3208
- Engines: unknown
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Phillip H. Nelson
- Registered owner: Phillip H. Nelson
- Departed: NONE, DURANGO, CO

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 50; commercial; flight hours: 226 total, 226 in this make and model, 214 as pilot in command, 6 in the last 90 days, 3 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 300° at 10 knots, gusting 15
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °F

## 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 19910202003899A](https://openairdocs.org/incident/19910202003899A), Feb 2, 1991: Raven RX7, Durango, CO, Substantial damage. Wind picked up after topping canyon. Entered downdraft. Unable clear wires.

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.

---
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.