# NTSB BFO91LA003: Mooney M20M, N987CM, Culpeper, VA, October 13, 1990

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: October 13, 1990, 15:10 local (19:10 UTC)
- Place: Culpeper, VA
- Coordinates: 38.46973, -78.00016 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.4697&lon=-78.0002&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 2 serious
- Status: Completed, report July 10, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 11635
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=BFO91LA003
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/11635/pdf
- Page: https://openairdocs.org/ntsb/BFO91LA003

## Probable cause

INTERGRANULAR CRACKING (FATIGUE) FAILURE OF THE EXHAUST CLAMP, WHICH RESULTED IN A DISCONNECTED EXHAUST MANIFOLD (TAILPIPE), AND SUBSEQUENT FIRE IN THE ENGINE COMPARTMENT.

## Sequence of events

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

- Airframe/component/system failure/malfunction, takeoff
  - exhaust system,clamp - fatigue (cause)
  - exhaust system,manifold/pipe - disconnected (cause)
- Fire, takeoff - roll/run
  - engine compartment - fire (cause)
  - fuselage,crew compartment - smoke
  - fuselage,crew compartment - fire
- Forced landing, descent - emergency
- In flight collision with terrain/water, landing
  - wheels up landing - performed, pilot in command
- On ground/water encounter with terrain/water, landing
  - terrain condition - ditch

## Analysis

THE PILOT INDICATED THAT DURING AN APPROACH TO LAND, HE NOTED THE SMELL OF A POSSIBLE OVERHEAT CONDITION, BUT THE ODOR WENT AWAY.  HE CHECKED THE ACFT AFTER LANDING, BUT DID NOT NOTICE ANY DISCREPANCIES.  HE TOOK OFF SHORTLY AFTERWARDS, AND DURING THE CLIMBOUT, SMOKE BEGAN FILLING THE CABIN.  THE SMOKE EMERGED FROM THE AREA OF THE RUDDER PEDALS AND FLAMES APPEARED SOON AFTERWARDS.  THE PLT TURNED BACK TO THE AIRPORT AND LANDED GEARUP.  THE ACFT SLID OFF THE RUNWAY AND INTO A DITCH.  A FIRE ERUPTED, BUT THE PLT AND PAX ESCAPED THE ACFT.  AN INVESTIGATION REVEALED INTERGRANULAR CRACKING OF THE CLAMP THAT CONNECTED THE TURBOCHARGER AND TAILPIPE.

## Aircraft

- Registration: [N987CM](https://openairdocs.org/deregistered/N987CM-1991-05-23), registration cancelled 1991-05-23, S/N 270013 (OpenAirDocs)
- Reported make and model: MOONEY M20M
- Registry model: [Mooney M20M](https://openairdocs.org/model/mooney-m20m) (registry code 5870222) (OpenAirDocs)
- Category: Airplane
- Serial number: 27-0013
- Airframe hours: 199
- Engines: LYCOMING TIO-540-AFIA 270 horsepower reciprocating
- Damage: Destroyed
- Fire: In-Flight
- Flight: Personal, Part 91
- Registered owner: Charles M. Hunter
- Airworthiness certificate: Standard, Normal
- Last inspection: Unknown, May 18, 1990, 74 hours before
- Departed: W49
- Destination: W10, MANASSAS, VA
- Airport: W49, Culpeper, runway 4, 4,000 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 62; private; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 2,000 total, 193 in this make and model, 1,885 as pilot in command, 83 in the last 90 days, 37 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 310° at 6 knots
- Visibility: 30 statute miles
- Lowest ceiling: 11,000 ft broken
- Temperature: 79 °F, dew point 70 °F
- Altimeter: 29.70 inHg
- Observed at: IAD, 15 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 19901013045109A](https://openairdocs.org/incident/19901013045109A), Oct 13, 1990: Mooney M20M, Culpeper, VA, Destroyed. Smoke and flames around rudder pedals on takeoff. Turned back. Landed gear up. Turbocharger tail pipe clamp broke.

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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