# NTSB DEN88FA193: Mooney M20F, N9528M, Jackson Hole, WY, August 27, 1988

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: August 27, 1988, 14:35 local (20:35 UTC)
- Place: Jackson Hole, WY
- Coordinates: 43.470516, -110.759643 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.4705&lon=-110.7596&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report December 6, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 17383
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN88FA193
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17383/pdf
- Page: https://openairdocs.org/ntsb/DEN88FA193

## Sequence of events

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

- Loss of control - in flight, climb - to cruise
  - aircraft weight and balance - improper, pilot in command (contributing factor)
  - weather condition - haze/smoke (contributing factor)
  - airspeed(vs) - not maintained, pilot in command (cause)
  - stall/spin - inadvertent, pilot in command (cause)
  - lack of recent instrument time, pilot in command (contributing factor)
  - spatial disorientation, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - mountainous/hilly
  - remedial action - inadequate, pilot in command (cause)

## Analysis

THE PVT PLT OBTAINED HIS INSTRUMENT RATING 14 DAYS PRIOR TO THE ACCIDENT. 12 HRS OF ACTUAL INSTRUMENT FLT TIME WAS LOGGED IN MARCH OF 1987. THE REMAINING INSTRUMENT FLT TIME WAS SIMULATED. VISIBILITY IN THE JACKSON HOLE AREA WAS REDUCED BY SMOKE. THE PLT REPORTED HE WAS CLIMBING THRU 11,000 FT FOR 14,000 FT. THE ACFT WRECKAGE WAS FOUND AT 9,000 FT. THE ACFT HAD STRUCK TWO TALL TREES AND FELL VERTICALLY TO THE GND. THE ACFT WEIGHT WAS CALCULATED TO BE NEAR MAX GROSS AND THE CG WAS DETERMINED TO BE BEYOND THE AFT LIMIT. THE PLT'S TOTAL INSTRUMENT FLT TIME WAS 42 HOURS. THE ACFT OWNERS MANUAL CONTAINS A WARNING WHICH STATE 'UP TO 2,000 FT OF ALTITUDE MAY BE LOST IN A ONE-TURN SPIN AND RECOVERY...THE RATE OF ROTATION DURING THE FIRST PORTION OF THE SPIN IS QUITE RAPID AND THE OCCUPANTS OF THE AIRCRAFT WILL LIKELY BECOME DISORIENTED.'

## Aircraft

- Registration: [N9528M](https://openairdocs.org/deregistered/N9528M-1991-03-26), registration cancelled 1991-03-26, S/N 670105 (OpenAirDocs)
- Reported make and model: MOONEY M20F
- Registry model: [Mooney M20F](https://openairdocs.org/model/mooney-m20f) (registry code 5870214) (OpenAirDocs)
- Category: Airplane
- Serial number: 670105
- Engines: LYCOMING IO-360-A1A 200 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Yoreck, Robert
- Registered owner: Mid Western Services Ltd.
- Airworthiness certificate: Standard, Normal
- Departed: JAC
- Destination: BJC, BROOMFIELD, CO
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 50; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 1,020 total, 285 in this make and model, 940 as pilot in command, 86 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 3 statute miles
- Lowest ceiling: none
- Temperature: 72 °F, dew point 39 °F
- Altimeter: 30.00 inHg
- Observed at: JAC, 12 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 19880827035729A](https://openairdocs.org/incident/19880827035729A), Aug 27, 1988: Mooney M20F, Jackson Hole, WY, Destroyed, 2 fatal. Impacted trees on a mountainside while circling to climb to cruise altitude. Visibility poor due forest fire smoke.

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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