# NTSB SEA84FA209: Benson B8M, N45684, Newman Lake, WA, August 22, 1984

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: August 21, 1984, 18:50 local (Aug 22, 1984, 01:50 UTC)
- Place: Newman Lake, WA
- Coordinates: 47.770702, -117.090927 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.7707&lon=-117.0909&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 39824
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA84FA209
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/39824/pdf
- Page: https://openairdocs.org/ntsb/SEA84FA209

## Sequence of events

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

- Loss of control - in flight, maneuvering
  - flight controls - improper use of, pilot in command (cause)
  - total, pilot in command (contributing factor)
  - inadequate initial training, pilot in command (contributing factor)
  - rotor system,main rotor blade - movement restricted (cause)
  - descent - uncontrolled, pilot in command
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - ground

## Analysis

WITNESSES OBSERVED THE AIRCRAFT GO THROUGH A SERIES OF RAPID PITCH OSCILLATIONS AT ABOUT 300 FT AGL. THE PITCH CHANGES INCREASED IN MAGNITUDE AND SEVERITY UNTIL THE MAIN ROTOR BLADES STRUCK THE RUDDER STOPPING IT'S ROTATION AND RESULTING IN AN UNCONTROLLED NEAR VERTICAL DESCENT. THERE WAS NO SOLO ENDORSEMENT ON THE STUDENT'S CERTIFICATE.

## Aircraft

- Registration: [N45684](https://openairdocs.org/deregistered/N45684-2014-12-03), registration cancelled 2014-12-03, S/N 495584628, built 1983 (OpenAirDocs)
- Reported make and model: BENSON B8M
- Registry model: [Campbell Richard D BENSEN B8M](https://openairdocs.org/model/campbell-richard-d-bensen-b8m) (registry code 13021LS) (OpenAirDocs)
- Registry engine: [Mcculloch ALL MDLS A/B](https://openairdocs.org/engine/mcculloch-all-mdls-a-b) (registry code 43102, reciprocating) (OpenAirDocs)
- Category: Gyroplane, amateur-built
- Serial number: 495584628
- Airframe hours: 25
- Engines: MCCULLOCH O-100-1 4318A 72 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Registered owner: Richard D. Campbell
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, January 13, 1984, 25 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 31; student; medical: class 3, valid medical--w/ waivers/lim; seat: center; toxicology performed; flight hours: 15 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 350° at 6 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 84 °F, dew point 36 °F
- Altimeter: 29.00 inHg
- Observed at: GEG, 19 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 19840821044669A](https://openairdocs.org/incident/19840821044669A), Aug 21, 1984: Amtrbx BENSENB8M, Newman Lake, WA, Destroyed. Over controlled while circling a street used for practice. Rotors struck the rudder and stopped turning.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.