# NTSB CHI90FA055: Beech A24R, N37329, Merrill, WI, December 28, 1989

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: December 28, 1989, 14:50 local (20:50 UTC)
- Place: Merrill, WI
- Coordinates: 45.179943, -89.699188 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=45.1799&lon=-89.6992&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 3 fatal
- Status: Completed, report June 28, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 14519
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI90FA055
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14519/pdf
- Page: https://openairdocs.org/ntsb/CHI90FA055

## Probable cause

FLIGHT INTO KNOWN ADVERSE WEATHER BY THE PILOT, AND STRUCTURAL/WING ICE.  FACTORS RELATED TO THE ACCIDENT WERE: THE ICING CONDITIONS AND TREES IN THE AREA OF THE ACCIDENT.

## Sequence of events

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

- In flight encounter with weather, cruise - normal
  - flight into known adverse weather - continued, pilot in command (cause)
  - weather condition - icing conditions (contributing factor)
  - fuselage - ice (cause)
  - wing - ice (cause)
  - climb - not possible
- Forced landing, descent - emergency
- In flight collision with object, descent
  - object - tree(s) (contributing factor)

## Analysis

THE ACFT COLLIDED WITH TREES & TERRAIN AS THE PLT WAS ATTEMPTING TO REACH AN ARPT.  HE HAD TOLD ATC PSNL THAT STRUCTURAL ICE WAS ACCUMULATING ON THE ACFT AND THAT HE WAS UNABLE TO MAINTAIN ALT.  SUBSEQUENTLY, THE ACFT DSCNDD BELOW AN ALT WHERE RADAR CONTACT COULD NOT BE MAINTAINED.  AIR & GROUND SEARCH PROCEDURES WERE STARTED AFTER ALL CONTACT WITH THE ACFT WAS LOST.  THREE DAYS LATER, THE ACFT WAS FOUND BY GROUND SEARCHERS.  THE WEATHER ALONG THE ROUTE CONSISTED OF LOW OVERCAST SKIES, BELOW FREEZING TEMPERATURES & FOG.  LAYERED PIECES OF ICE WERE FOUND IN THE WRECKAGE AREA, WHICH WERE 3/4 TO 1-1/4 INCH THICK; THESE PIECES OF ICE CONTAINED INNER SURFACES THAT MATCHED THE SHAPE OF AIRFOILS.  WEATHER IN THE AREA WAS INFLUENCED BY A WARM FRONT WITH LOW OVERCAST SKIES, FREEZING TEMPS & FOG TO THE NORTH OF THE FRONT.  BEFORE THE FLT, THE PLT WAS ADVISED OF OCCASIONAL MODERATE RIME ICING ALONG HIS ROUTE.

## Aircraft

- Registration: [N37329](https://openairdocs.org/deregistered/N37329-1998-03-28), registration cancelled 1998-03-28, S/N MC738 (OpenAirDocs)
- Reported make and model: BEECH A24R
- Registry model: [Beech C24R](https://openairdocs.org/model/beech-c24r) (registry code 1151254) (OpenAirDocs)
- Category: Airplane
- Serial number: MC-738
- Engines: LYCOMING IO-360-A1B6 200 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Operator: 37329 Inc.
- Registered owner: Unknown
- Departed: IWE, IRONWOOD, MI
- Destination: C77, BELVIDERE, IL
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; toxicology performed; flight hours: 740 total, 65 in this make and model

## Weather

- Conditions: Day
- Temperature: -0 °F, dew point -0 °F

## 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 19891228057269A](https://openairdocs.org/incident/19891228057269A), Dec 28, 1989: Beech C24R, Wausau, WI, Destroyed, 3 fatal. Departed into known icing conditions. Unable to hold altitude descended into trees. Airframe was heavily iced.

## Other investigations on N37329 (1)

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.

- [NTSB CHI81FEE10](https://openairdocs.org/ntsb/CHI81FEE10), Dec 4, 1980: Beech C24R (N37329), West Chicago, IL, substantial damage

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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