# NTSB DEN02LA075: American General AA5B, N28717, Worland, WY, July 13, 2002

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: July 13, 2002, 09:30 local (15:30 UTC)
- Place: Worland, WY
- Coordinates: 44.204166, -107.26667
- Nearby events: https://openairdocs.org/map.md?lat=44.2042&lon=-107.2667&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 uninjured
- Status: Completed, report December 6, 2002
- Report: Approved by Office Director
- Parties: FAA Flight Standards Field Office
- NTSB case key (mKey): 55257
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN02LA075
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/55257/pdf
- Page: https://openairdocs.org/ntsb/DEN02LA075

## Probable cause

the pilot's selection of an inadequate altitude for crossing mountainous terrain, resulting in a collision with trees. A contributing factor was the downdraft.

## 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 - downdraft (contributing factor)
  - altitude/clearance - inadequate, pilot in command (cause)
- In flight collision with object, maneuvering - turn to reverse direction
  - object - tree(s)

## Analysis

The pilot said he was crossing a mountain range approximately 800 feet above each series of mountains. A downdraft caused the airplane to lose both altitude and airspeed. Rising terrain prevented him from completing a 180-degree turn and the airplane struck a tree then impacted the ground.

## Factual narrative

On July 13, 2002, approximately 0930 mountain daylight time, a Grumman American AA5B, N28717, was substantially damaged when it struck terrain while maneuvering near Worland, Wyoming. Both the airline transport pilot was seriously injured, but his passenger sustained only minor injuries. Day visual meteorological conditions prevailed, and no flight plan had been filed for the cross-country flight being conducted under Title 14 CFR Part 91. The flight originated in Cody, Wyoming, at 0840, and was en route to Valentine, Nebraska.

In his accident report, the pilot said he was crossing the Big Horn mountain range approximately 800 feet above each series of ridges. He wrote, "After crossing a set of mountains, we hit a downdraft, causing both loss of altitude and loss of airspeed. We attempted a 180-degree turn to get out of the downdraft, but combined with the rising terrain, we were unable to complete the turn. We hit a tree lot at 70 KIAS (knots indicated airspeed) and then impacted the ground."

Both wings and the landing gear were torn off the airplane.

## Aircraft

- Registration: [N28717](https://openairdocs.org/deregistered/N28717-2006-07-19), registration cancelled 2006-07-19, S/N AA5B0771, built 1978 (OpenAirDocs)
- Reported make and model: American General Aircraft AA5B
- Registry model: [Grumman American Avn. AA-5B](https://openairdocs.org/model/grumman-american-avn-aa-5b) (registry code 3960105) (OpenAirDocs)
- Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: AA5B-0771
- Engines: Lycoming O-360-A4K 180 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Registered owner: Gregg S. Wilson
- Airworthiness certificate: Standard, Normal
- Departed: COD, Cody, WY
- Destination: VTN, Valentine, NE

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; injuries: minor; flight instructor, commercial, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; last flight review October 28, 2000; seat: left; flight hours: 4,464 total, 1,400 in this make and model, 4,084 as pilot in command, 42 in the last 90 days, 15 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 73 °F, dew point 46 °F
- Altimeter: 30.05 inHg
- Observed at: WRL, 52 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 20020713018499A](https://openairdocs.org/incident/20020713018499A), Jul 13, 2002: Amrgen AA5B, Worland, WY, Substantial damage. (-23) Pilot departed cody, WY with one passenger, for VFR flight to valentine, NE. Pilot elected to fly over the bighorn mountain range in central Wyoming.…

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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