# NTSB SEA98LA033: Sherman Executive, N50499, Stayton, OR, January 31, 1998

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Limited investigation · Final report
- Date: January 31, 1998, 14:00 local (22:00 UTC)
- Place: Stayton, OR
- Coordinates: 44.809112, -122.71939 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=44.8091&lon=-122.7194&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report February 15, 2001
- Report: Approved by Office Director
- NTSB case key (mKey): 42753
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA98LA033
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42753/pdf
- Page: https://openairdocs.org/ntsb/SEA98LA033

## Probable cause

Main rotor strike and separation of the tail boom for undetermined reasons.

## Analysis

The amateur-built helicopter collided with terrain after in-flight separation of its tail boom and tail rotor while maneuvering.  Witnesses described the helicopter making about 4 passes over the field at about 500 feet above the surface.  On the last pass, there was a hard yaw to the right; the helicopter then straightened out, pitched into a flare, then the tail came up and the main rotor struck the tail-boom.  The tail-boom, tail rotor, and bubble canopy separated from the helicopter.  The main wreckage was located about 300 feet from those components.

## Factual narrative

On January 31, 1998, approximately 1400 Pacific standard time, N50499, a amateur-built Sherman Executive helicopter, collided with terrain after in-flight separation of its tail boom and tail rotor while maneuvering, near Stayton, Oregon.  The two occupants, a commercial helicopter pilot and the owner (a private pilot) were fatally injured.  The helicopter had departed Salem, Oregon, on a training flight for the private pilot.  Visual meteorological conditions prevailed at the time of the accident.  The wreckage was consumed by fire.  There was no ELT onboard the aircraft.

Witnesses described the helicopter making about 4 passes over the field at about 500 feet above the surface.  On the last pass, there was a hard yaw to the right; the helicopter then straightened out, pitched into a flare, then the tail came up and the main rotor struck the tail-boom.  The tail-boom, tail rotor, and bubble canopy separated from the helicopter.  The main wreckage was located about 300 feet from those components.

The owner-builder had brought the helicopter to Salem to acquire helicopter flight training.  The commercial pilot had extensive experience in helicopters, but he did not have a flight instructor certificate.

Toxicological testing on both pilots on board the helicopter was negative.  Autopsies of the two occupants were performed at Portland, Oregon by Drs. Nikolas J. Hartshorne and Steve Shapiro.  The NTSB did not take possession of the aircraft.

## Sequence of events

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

- Loss of control - in flight, maneuvering
  - misc rotorcraft,tail boom - separation (cause)
  - reason for occurrence undetermined
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - ground

## Aircraft

- Registration: [N50499](https://openairdocs.org/deregistered/N50499-2001-05-04), registration cancelled 2001-05-04, S/N ES002 (OpenAirDocs)
- Reported make and model: Sherman EXECUTIVE
- Registry model: [Sherman Evan EXEC](https://openairdocs.org/model/sherman-evan-exec) (registry code 05605IW) (OpenAirDocs)
- Category: Helicopter, amateur-built
- Serial number: ES002
- Engines: Rotorway RW152D 150 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Instructional, Part 91
- Registered owner: Evan J. Sherman
- Airworthiness certificate: Special, Experimental (Special)
- Departed: SALEM, OR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 33; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: helicopter; medical: class 2, expired; seat: left; toxicology performed; flight hours: 2,500 total

## Weather

- Conditions: Visual (VMC), Day
- Lowest ceiling: none
- Temperature: 52 °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 19980131002749A](https://openairdocs.org/incident/19980131002749A), Jan 31, 1998: Amtr EXEC, Stayton, OR, Destroyed, 2 fatal. PIC or student made abrupt control movements. Main rotors severed tailboom.(.4)the amateur-built helicopter collided with terrain after in-flight separation of…

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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