# NTSB DEN83LA082: American AA-5B, N4520V, Heber City, UT, March 21, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 21, 1983, 07:38 local (14:38 UTC)
- Place: Heber City, UT
- Coordinates: 40.430473, -111.190231 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.4305&lon=-111.1902&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 16055
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN83LA082
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/16055/pdf
- Page: https://openairdocs.org/ntsb/DEN83LA082

## Sequence of events

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

- Loss of control - in flight, maneuvering - turn to reverse direction
  - terrain condition - high terrain (contributing factor)
  - weather condition - high density altitude (contributing factor)
  - proper climb rate - not possible, pilot in command (cause)
  - in-flight planning/decision - delayed, pilot in command (cause)
  - airspeed - not maintained, pilot in command (cause)
  - stall - inadvertent, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - mountainous/hilly (contributing factor)
  - terrain condition - snow covered (contributing factor)

## Analysis

AFTER TAKING OFF AT HEBER CITY, UT, THE PLT TURNED TO A 090 DEG HEADING & BEGAN A CLIMB WITH FULL THROTTLE, MIXTURE FULL RICH, 80 TO 90 KIAS & APRX 500 FPM RATE OF CLIMB. AT APRX 6500 FT MSL, HE ALTERED THE COURSE TO 110 TO 115 DEG TO PROVIDE BETTER TERRAIN CLEARANCE, OVER A SLIGHT VALLEY FORMED BY CREEK DRAINAGE. AT THAT POINT, THE CLEARANCE WAS REPORTEDLY ABOUT 1000 FT. AS THE CLIMB CONTINUED, THE PLT NOTICED THAT THE TERRAIN WAS GRADUALLY GETTING CLOSER. AS HE NEARED THE TOP, HE SUDDENLY REALIZED THAT THE ACFT MIGHT NOT BE ABLE TO MAKE IT OVER. A 180 DEG TURN WAS STARTED. HOWEVER, AS A LEFT BANK WAS ESTABLISHED FOR THE TURN, THE ACFT FELT MUSHY & STARTED TO LOSE ALT RAPIDLY. THE PLT ROLLED THE WINGS LEVEL & PULLED BACK ON THE YOKE WHEN GROUND CONTACT WAS POSSIBLE. HOWEVER, THE DESCENT CONTINUED & THE ACFT CRASHED ON A TREELESS, SNOW CVRD SLOPE AT 9300 FT. THE PLT SUGGESTED CARBON MONOXIDE MIGHT EXPLAIN HIS INDECISIVENESS, BUT AN EXAM OF THE ENG & EXHAUST SYS REVEALED NO PREIMPACT MALFUNCTION OR FAILURE.

## Aircraft

- Registration: N4520V (not matched to a registry record)
- Reported make and model: AMERICAN AA-5B
- Category: Airplane
- Serial number: AA5B1066
- Airframe hours: 1525
- Engines: LYCOMING O-360-A4K 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Operator: Mercury Aircourier Service
- Registered owner: Lake Aero, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, September 7, 1982, 27 hours before
- Departed: 36U, HEBER CITY, UT
- Destination: U69, DUSCHESNE, UT
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; airline transport; airplane ratings: multi-engine sea, multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 7,469 total, 153 in this make and model, 5,435 as pilot in command, 150 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 150° at 10 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 16 °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 19830321008629A](https://openairdocs.org/incident/19830321008629A), Mar 21, 1983: Gulstm AA5B, Heber City, UT, Substantial damage. Unable to outclimb rising terrain. Crash landed on a snowy slope. Pilot failed to note situation until too late.

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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