# NTSB MIA91FA008: Mooney M20C, N1389W, Kissimmee, FL, October 7, 1990

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Field investigation · Final report
- Date: October 7, 1990, 12:30 local (16:30 UTC)
- Place: Kissimmee, FL
- Location: 28.3062° N, 81.4135° W: Placed by OpenAirDocs: center of Kissimmee, FL, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=28.3062&lon=-81.4135&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 2 serious
- Status: Completed, report April 14, 1992
- Report: Approved by Office Director
- ADs cited in the narratives: [AD 73-07-04](https://openairdocs.org/ad/73-07-04) (OpenAirDocs)
- NTSB case key (mKey): 32732
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA91FA008
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/32732/pdf
- Page: https://openairdocs.org/ntsb/MIA91FA008

## Probable cause

MALFUNCTION OF BOTH MAGNETOS DUE TO DETERIORATION OF THE COILS, FAILURE OF MAINTENANCE PERSONNEL TO COMPLY WITH AN AIRWORTHINESS DIRECTIVE, AND FAILURE OF THE PILOT TO MAINTAIN ADEQUATE VISUAL LOOKOUT WHILE ON AN APPROACH FOR AN EMERGENCY LANDING. FACTORS RELATED TO THE ACCIDENT WERE: THE OBSTRUCTION (TREE) IN THE EMERGENCY LANDING AREA, AND DIVERSION OF THE PILOT'S ATTENTION WHILE APPROACHING TO LAND.

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, cruise
  - ignition system,magneto - deteriorated (cause)
  - maintenance,compliance with ad - not performed, other maintenance personnel (cause)
- Forced landing, descent - emergency
- In flight collision with object, approach
  - object - tree(s) (contributing factor)
  - visual lookout - inadequate, pilot in command (cause)
  - diverted attention, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PLT RPRTD THE ENG STARTED & RAN NORMALLY BEFORE TAKEOFF. HOWEVER, DURING FLT, IT BEGAN RUNNING ROUGH. THE PLT REDUCED THE POWER SETTING WHICH INITIALLY ELIMINATED THE ENG ROUGHNESS. HE CHECKED EACH MAGNETO & NOTED NO MALFUNCTION; HOWEVER, WHILE DIVERTING TO A NEARBY ARPT, THE ENG AGAIN BEGAN RUNNING ROUGH & A SEVERE LOSS OF POWER OCCURRED. ACCORDING TO WITNESSES, THE ACFT STRUCK A PALM TREE DURING A LEFT DESCENDING TURN AT LOW ALTITUDE & CRASHED. THE ENG WAS EQUIPPED WITH BENDIX MODEL S4LN-200 SERIES MAGNETOS. DURING A BENCH CHECK BOTH MAGNETOS BEGAN MISFIRING AFTER ABOUT 15 TO 20 MIN OF OPN. DISASSEMBLY OF THE MAGNETOS REVEALED THE NONCONDUCTIVE MATERIAL IN THE COILS WAS CRACKED & WAS BEGINNING TO LIQUEFY; THIS RESULTED IN MISDIRECTION OF THE HIGH VOLTAGE SPARK. THE MAGNETOS HAD APRX 2316 HRS IN SVC. ACCORDING TO AD 73-07-04, THE COILS IN THE MAGNETOS OF THIS ACFT SHOULD HAVE BEEN REPLACED AFTER ACCUMULATING APRX 2000 HRS OF OPN. THE ACFT HAD FLOWN 11 HRS SINCE THE LAST ANNUAL INSPN.

## Aircraft

- Registration: [N1389W](https://openairdocs.org/deregistered/N1389W-1991-06-18), registration cancelled 1991-06-18, S/N 2667 (OpenAirDocs)
- Reported make and model: MOONEY M20C
- Registry model: [Mooney M20C](https://openairdocs.org/model/mooney-m20c) (registry code 5870208) (OpenAirDocs)
- Category: Airplane
- Serial number: 2667
- Airframe hours: 2316
- Engines: LYCOMING O-360-A1D 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: L. G. & P. W. Blendermann
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 13, 1990, 22 hours before
- Departed: SUA, STUART, FL
- Destination: TOC, TOCCOA, GA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 47; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 581 total, 581 as pilot in command, 2 in the last 90 days, 1 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 80° at 14 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 84 °F, dew point 66 °F
- Altimeter: 29.89 inHg
- Observed at: MCO, 12 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 19901007047279A](https://openairdocs.org/incident/19901007047279A), Oct 7, 1990: Mooney M20C, Kissimmee, FL, Substantial damage. Engine rough and loosing power stalled just above house tops and crashed. Magneto coils shorted. AD not complied.

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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