# NTSB DEN86LA164: Piper PA-25-260, N82539, Toston, MT, June 18, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: June 18, 1986, 08:30 local (14:30 UTC)
- Place: Toston, MT
- Coordinates: 46.16901, -111.50959 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.1690&lon=-111.5096&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): 16983
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN86LA164
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/16983/pdf
- Page: https://openairdocs.org/ntsb/DEN86LA164

## Sequence of events

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

- Loss of control - in flight, maneuvering - aerial application
  - weather condition - high density altitude (contributing factor)
  - stall/mush - inadvertent, pilot in command (cause)
  - load jettison - initiated, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PLT REPORTS THAT HE TOOK OFF FROM AN AG STRIP ABOUT A MILE FROM THE FLD BEING TREATED AND WAS MAKING A TURN-AROUND AFTER HIS SECOND SWATH RUN WHEN THE ACFT BEGAN TO SETTLE. HE DUMPED HIS CHEM BUT THE ACFT CONTINUED TO SETTLE AND IMPACTED THE GROUND. THE PLT SAID THE TURN-AROUND WAS BEING MADE BESIDE A BUTTE AND HE ENCOUNTERED 'BAD AIR.' THE DENSITY ALT AT THE TIME AND PLACE OF THE ACDT IS CALCULATED TO BE ABOUT 5,000 FT. THE PLT SAID THERE WAS NO MALFUNCTION OF THE ACFT OR ENG.

## Aircraft

- Registration: N82539 (not matched to a registry record)
- Reported make and model: PIPER PA-25-260
- Category: Airplane
- Serial number: 7756054
- Airframe hours: 1806
- Engines: LYCOMING O-540-G1A5 260 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Quality Spraying
- Registered owner: Boyd J. Morgan
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, March 22, 1986, 133 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; flight hours: 2,329 total, 2,000 in this make and model, 125 in the last 90 days, 10 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 270° at 4 knots
- Visibility: 30 statute miles
- Lowest ceiling: 20,000 ft broken
- Temperature: 63 °F, dew point 46 °F
- Altimeter: 29.00 inHg
- Observed at: BZN, 22 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 19860618026709A](https://openairdocs.org/incident/19860618026709A), Jun 18, 1986: Piper PA25235, Toston, MT, Substantial damage. While turning, aircraft started to settle. Pilot dumped load but was unable to recover. High density altitude.

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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