# NTSB NYC92FA055: Aero Commander 500S, N725AC, Richmond Hts., OH, February 7, 1992

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: February 6, 1992, 21:01 local (Feb 7, 1992, 02:01 UTC)
- Place: Richmond Hts., OH
- Coordinates: 41.54924, -81.479476 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.5492&lon=-81.4795&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report June 21, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 37051
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC92FA055
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/37051/pdf
- Page: https://openairdocs.org/ntsb/NYC92FA055

## Probable cause

THE PILOT'S IMPROPER EMERGENCY PROCEDURES AND FAILURE TO MAINTAIN CONTROL OF THE AIRPLANE, WHICH RESULTED IN AN INADVERTENT SPIN AT TOO LOW AN ALTITUDE TO ALLOW RECOVERY. FACTORS IN THIS ACCIDENT WERE; A POWER LOSS IN THE LEFT ENGINE AS RESULT OF THE EXHAUST VALVE FAILURES IN CYLINDERS #3 AND #5.

## Sequence of events

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

- Loss of engine power, climb
  - engine assembly,valve,exhaust - burned (contributing factor)
  - 1 engine - failure,total (contributing factor)
- Loss of control - in flight, descent - uncontrolled
  - emergency procedure - improper, pilot in command (cause)
  - lack of total experience in type of aircraft, pilot in command
  - aircraft control - not maintained, pilot in command (cause)
  - stall/spin - inadvertent, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - ground

## Analysis

THE PILOT HAD THE WASTE GATES ON THE TURBOCHARGES ADJUSTED AND WANTED TO TEST FLY THE AIRPLANE AFTER THE WORK WAS COMPLETED.  THE AIRPLANE DEPARTED AND HAD REACHED AN ALTITUDE OF ABOUT 1000 FEET WHEN WITNESSES HEARD AN ENGINE SPUTTER.  THE AIRPLANE WAS SEEN MAKING A LEFT TURN AND ENTER A NOSE LOW, LEFT SPIN BEFORE IMPACTING THE TERRAIN.  A TEAR DOWN OF THE LEFT ENGINE REVEALED THAT THE EXHAUST VALVES IN CYLINDERS #3 AND #5 WERE BURNT THROUGH AT THE VALVE HEAD.  THE #5 EXHAUST VALVE HAD A DEEP PREEXISTING DEEP MARK ON THE VALVE STEM.  THE FAILURES OF BOTH VALVES WERE SUFFICENT ENOUGH TO CAUSE A POWER FAILURE IN THE LEFT ENGINE.

## Aircraft

- Registration: [N725AC](https://openairdocs.org/deregistered/N725AC-1995-06-07), registration cancelled 1995-06-07, S/N 3144 (OpenAirDocs)
- Reported make and model: AERO COMMANDER 500S
- Registry model: [Aero Commander 500 S](https://openairdocs.org/model/aero-commander-500-s) (registry code 0141107) (OpenAirDocs)
- Category: Airplane
- Serial number: 3144
- Airframe hours: 3276
- Engines: LYCOMING IO-540-E1B5 290 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Operator: Michael Stanton-Hicks
- Registered owner: Shrike Corporation
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, July 26, 1991, 500 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; private; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 1,111 total, 71 in this make and model, 930 as pilot in command, 18 in the last 90 days, 8 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 260° at 10 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 36 °F
- Altimeter: 29.00 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 19920206001969A](https://openairdocs.org/incident/19920206001969A), Feb 6, 1992: Gulstm 500S, Cleveland, OH, Destroyed, 1 fatal. Witness saw left engine fire on climbout. Lost control spun in on downwind. Found leaky valves. Fire undetermined.

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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