# NTSB DEN88LA134: Cessna T188C, N4970J, Big Timber, MT, June 22, 1988

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: June 22, 1988, 07:00 local (13:00 UTC)
- Place: Big Timber, MT
- Coordinates: 45.960212, -109.849601 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=45.9602&lon=-109.8496&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report June 9, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 17484
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN88LA134
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17484/pdf
- Page: https://openairdocs.org/ntsb/DEN88LA134

## 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 - downdraft (contributing factor)
  - stall - inadvertent, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PLT SAID HE WAS SPRAYING 2,4,D ON TWO BARLEY FLDS. HE HAD COMPLETED ONE FLD AND WAS TURNING AROUND WHEN THE ACFT BEGAN TO SETTLE. HE SAID WHEN HE ATTEMPTED TO AVOID GROUND CONTACT THE ACFT STALLED AND COLLIDED WITH THE GROUND. DURING A TELEPHONE CONVERSATION ON THE DAY OF THE ACCIDENT THE PLT SAID THERE WAS NOTHING WRONG WITH THE ACFT OR ENG AND THAT HE JUST MUST HAVE HIT 'DEAD AIR' (A DOWNDRAFT OR TAILWIND). SEVERAL DAYS AFTER THE ACCIDENT THE PLT REPORTED THAT IN HIS OPINION THE ENG WAS NOT PRODUCING POWER AT THE TIME OF THE ACCIDENT. THE ENG WAS THEN DISASSEMBLED BUT NO EVIDENCE TO SUPPORT A LOSS OF PWR WAS FOUND.

## Aircraft

- Registration: [N4970J](https://openairdocs.org/deregistered/N4970J-1999-07-12), registration cancelled 1999-07-12, S/N T18803792T (OpenAirDocs)
- Reported make and model: CESSNA T188C
- Registry model: [Cessna T188C](https://openairdocs.org/model/cessna-t188c) (registry code 2073012) (OpenAirDocs)
- Category: Airplane
- Serial number: T18803792T
- Airframe hours: 1225
- Engines: CONTINENTAL TSIO-520-T 310 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Yellowstone Air Service
- Registered owner: Yellowstone Air Service
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, May 5, 1988, 61 hours before
- Departed: 6SO, BIG TIMBER, MT
- Destination: 6SO

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 60; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 14,200 total, 3,800 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 70 statute miles
- Lowest ceiling: none
- Temperature: 55 °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 19880622022729A](https://openairdocs.org/incident/19880622022729A), Jun 22, 1988: Cessna T188C, Big Timber, MT, Substantial damage. Stalled and crashed during a turnaround from a spray run.

## Other investigations on N4970J (1)

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.

- [NTSB SEA96LA114](https://openairdocs.org/ntsb/SEA96LA114), Jun 7, 1996: Cessna T188C (N4970J), Roundup, MT, destroyed. Probable cause: failure of the pilot to maintain adequate airspeed, during a turn-around maneuver after a swath run, which resulted in an inadvertent stall.

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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