# NTSB FTW86FA092: Cessna 210M, N750RS, Calumet, OK, May 24, 1986

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: May 24, 1986, 00:28 local (05:28 UTC)
- Place: Calumet, OK
- Coordinates: 35.599563, -98.120452 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.5996&lon=-98.1205&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 21907
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW86FA092
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/21907/pdf
- Page: https://openairdocs.org/ntsb/FTW86FA092

## Sequence of events

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

- In flight encounter with weather, descent - normal
  - weather condition - clouds (contributing factor)
  - weather condition - low ceiling (contributing factor)
  - weather condition - haze/smoke (contributing factor)
  - light condition - dark night (contributing factor)
  - vfr flight into imc - attempted, pilot in command (cause)
- Loss of control - in flight, descent - normal
  - flight/nav instruments,attitude gyro - failure,total (cause)
  - remedial action - attempted, pilot in command
  - flight/nav instruments,attitude gyro - false indication (cause)
  - spiral - not corrected, pilot in command (cause)
  - lack of recent instrument time, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

ACFT ON A NIGHT XC FLT IN MARGINAL VFR TO IMC CONDITIONS IMPACTED IN AN 80 DEG NOSE DOWN ATTITUDE IN A LEFT SPIRAL. IMMEDIATELY PRIOR TO THE ACCIDENT THE NON-INSTRUMENT RATED PVT PLT HAD INDICATED THAT HE WAS IMC AND WAS GOING TO ATTEMPT TO CLIMB OUT OF IT. RADAR DATA INDICATED THAT THE ACFT STARTED A CLIMBING LEFT TURN AND THEN ENTERED A LEFT SPIRALING DESCENT. INVESTIGATION REVEALED THAT THE ATTITUDE INDICATOR GYRO HAD FAILED AND WAS NOT ROTATING AT OPERATIONAL RPM AT THE TIME OF IMPACT. EXAMINATION OF THE VACUUM PUMP AND THE HSI GYRO INDICATED THAT THEY WERE OPERATING NORMALLY. THERE WAS NO INTERNAL FAILURE IN THE ATTITUDE INDICATOR AND THE REASON FOR THE FAILURE WAS NOT DETERMINED DUE TO THE LEVEL OF DAMAGE SUSTAINED IN THE FIRE WALL AND INSTRUMENT PANEL AREAS. THE PVT PLT HAD LAST PRACTICED INSTRUMENT FLT 3 YEARS PRIOR TO THE ACCIDENT.

## Aircraft

- Registration: N750RS (not matched to a registry record)
- Reported make and model: CESSNA 210M
- Category: Airplane
- Serial number: 21061923
- Airframe hours: 1526
- Engines: CONTINENTAL IO-520-L3A 285 horsepower reciprocating
- Damage: Destroyed
- Flight: Business, Part 91
- Registered owner: Thomas A. Harmon
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 12, 1985, 129 hours before
- Departed: DEN, DENVER, CO
- Destination: WPA, OKLAHOMA CITY, OK
- Airport: OKC, Oklahoma City Int'L

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 51; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 2,416 total, 2,301 in this make and model, 2,368 as pilot in command, 47 in the last 90 days, 23 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Night/dark
- Wind: 40° at 12 knots
- Visibility: 4 statute miles
- Lowest ceiling: 1,000 ft overcast
- Temperature: 70 °F, dew point 66 °F
- Altimeter: 29.00 inHg
- Observed at: OKC, 31 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 19860524019429A](https://openairdocs.org/incident/19860524019429A), May 24, 1986: Cessna 210M, Calumet, OK, Destroyed, 1 fatal. The VFR pilot lost control of the aircraft in IFR conditions. Attitude indicator malfunctioned.

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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