# NTSB CHI86LA067: Sikorsky S-58F, N885, North Adams, MI, January 16, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: January 16, 1986, 14:05 local (19:05 UTC)
- Place: North Adams, MI
- Coordinates: 41.969734, -84.520721 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.9697&lon=-84.5207&mi=10
- Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 13409
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI86LA067
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/13409/pdf
- Page: https://openairdocs.org/ntsb/CHI86LA067

## Sequence of events

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

- Airframe/component/system failure/malfunction, standing - engine(s) operating
  - rotorcraft flight control system,primary servo - failure,partial (cause)
  - rotorcraft flight control system - exhaustion (cause)
  - cyclic - uncontrolled, pilot in command (contributing factor)
  - collective - uncontrolled, pilot in command (contributing factor)
  - throttle/power control - uncontrolled, other maintenance personnel (cause)
  - maintenance - inadequate, pilot in command (contributing factor)
- Roll over, standing - engine(s) operating
  - directional control - not possible, pilot in command (cause)

## Analysis

WHILE ACCOMPLISHING PREFLIGHT SYSTEMS CHECKS WITH THE ENGINE RUNNING AND THE ROTOR SYSTEM ENGAGED THE AIRCRAFT EXPERIENCED A HYDRAULIC HARDOVER. UNCOMMANDED DISPLACEMENT OF THE FLIGHT CONTROLS CAUSED THE AIRCRAFT TO PITCH UP AND LEFT SIMULTANEOUSLY. THE PILOT WAS UNABLE TO REGAIN CONTROL BEFORE THE MAIN ROTOR BLADES STRUCK THE GROUND AND THE AIRCRAFT CAME TO REST ON ITS LEFT SIDE. TESTING OF THE HYDRAULIC SYSTEM COULD NOT DUPLICATE THE PROBLEM. TEARDOWN INSPECTION REVEALED FOREIGN MATERIAL IN THE HYDRAULIC CYLINDERS.

## Aircraft

- Registration: N885 (not matched to a registry record)
- Reported make and model: SIKORSKY S-58F
- Category: Helicopter
- Serial number: 58396
- Airframe hours: 7614
- Engines: WRIGHT R-1820-84 1475 horsepower reciprocating
- Damage: Substantial damage
- Flight: Other work use, Part 133
- Registered owner: B & G Helicopter Corp.
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, September 9, 1985, 43 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; commercial, flight instructor; instrument ratings: helicopter; medical: class 1, unknown; seat: right; flight hours: 8,052 total, 380 in this make and model, 5,862 as pilot in command, 90 in the last 90 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 240° at 5 knots
- Visibility: 7 statute miles
- Lowest ceiling: none
- Temperature: 39 °F, dew point 36 °F
- Altimeter: 30.00 inHg

## 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 19860116000769A](https://openairdocs.org/incident/19860116000769A), Jan 16, 1986: Skrsky S58F, North Adams, MI, Substantial damage. During system checks with rotors idling, collective and cylic activated when auxiliary. Hydraulics were turned off.

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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