# NTSB MKC90DCQ02: Bell UH-1B, N8142W, Ulysses, KS, May 6, 1990

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Final report
- Date: May 6, 1990, 17:15 local (22:15 UTC)
- Place: Ulysses, KS
- Coordinates: 37.570838, -101.349205 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.5708&lon=-101.3492&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report December 10, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 34868
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC90DCQ02
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/34868/pdf
- Page: https://openairdocs.org/ntsb/MKC90DCQ02

## Probable cause

THE PILOT FAILED TO MAINTAIN PROPER ROTOR RPM, WHILE MANEUVERING OVER A HIGH OBSTRUCTION (POWER LINE) AT THE END OF A SWATH RUN, WHICH RESULTED IN AN INADVERTENT DESCENT & COLLISION WITH THE TERRAIN.  THE HIGH OBSTRUCTION WAS CONSIDERED TO BE A RELATED FACTOR.

## Sequence of events

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

- In flight collision with terrain/water, maneuvering - aerial application
  - terrain condition - high obstruction(s) (contributing factor)
  - pull-up - performed
  - rotor rpm - not maintained, pilot in command (cause)
  - descent - inadvertent, pilot in command (cause)

## Analysis

THE HELICOPTER WAS REFUELED & LOADED WITH A SPRAY MIX, THEN THE PLT PROCEEDED TO A FIELD & BEGAN AERIAL APPLICATION. AFTER THE 2ND SWATH RUN, HE MANEUVERED THE HELICOPTER UP & OVER 'BIG' POWER LINES ON THE EAST END OF THE FIELD.  AT ABOUT THAT TIME, THE HELICOPTER ENTERED A DESCENT & CRASHED. NO PREIMPACT MECHANICAL PROBLEM WAS FOUND DURING THE INVESTIGATION. THE OWNER ESTIMATED THE HELICOPTER HAD ABOUT 1983 LBS OF SPRAY & 900 LBS OF FUEL ON BOARD WHEN IT CRASHED.

## Aircraft

- Registration: [N8142W](https://openairdocs.org/deregistered/N8142W-1990-11-21), registration cancelled 1990-11-21, S/N 638566 (OpenAirDocs)
- Reported make and model: BELL UH-1B
- Registry model: [Bell UH-1B](https://openairdocs.org/model/bell-uh-1b) (registry code 1181410) (OpenAirDocs)
- Category: Helicopter
- Serial number: 63-8566
- Airframe hours: 4768
- Engines: LYCOMING T53-L-11D 1100 horsepower turbo shaft
- Damage: Destroyed
- Fire: On-Ground
- Flight: Aerial application, Part 137
- Registered owner: Tri-Rotor Spray & Chemical
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, February 27, 1990, 30 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; commercial, flight instructor; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 5,677 total, 2,500 in this make and model, 200 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 16 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 75 °F, dew point 43 °F
- Altimeter: 29.00 inHg
- Observed at: GCK, 45 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 19900506013999A](https://openairdocs.org/incident/19900506013999A), May 6, 1990: Bell UH1B, Ulysses, KS, Substantial damage, 1 fatal. Wreckage shows evidence of mast bumping and low rotor RPM occurred prior loss of control crash and burn.

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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