FLIGHT FINDINGSAVIATION OCCURRENCE MAP
Back to map

CHI90FA055 · Beech A24R

28 Dec 1989 · Merrill, WI, United States

37329 Beech A24R · Accident: in flight encounter with weather en route

From IWE · Ironwood, MI to Poplar Grove Airport (C77)

Report a problem

Event

NTSB case
CHI90FA055
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
3 · all aircraft and ground
Ground fatalities
0
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Unknown

Beech A24R

Aircraft type
Beechcraft 24
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N37329
Operator
37329
Onboard fatalities
Unknown
Route
From IWE · Ironwood, MITo Poplar Grove Airport (C77), Belvidere, IL
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 91: General Aviation
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
En route · cruise
First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
In flight encounter with weather
Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
Tree(s)
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Destroyed

Cause areas

  • Fuselage › Ice
  • Pilot in command › Flight into known adverse weather, continued
  • Wing › Ice

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

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.

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.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record CHI90FA055
Event ID
20001213X29924
Case number
CHI90FA055
Dataset
historical-pre2008
Source SHA-256
89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: 3d279d363e825480a4884dfdddb33b6f95eb0dbb8e83320c51c367787a9fe366; retrieved 2026-09-21T03:03:09.751Z.