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CHI98FA017 · Beech G35

6 Oct 1997 · Poplar Grove, IL, United States

Beech G35 · Accident: airframe, component or system failure en route

From Southern Wisconsin Regional Airport (JVL) to C77

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Event

NTSB case
CHI98FA017
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
0 · 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
Visual Meteorological Cond

Beech G35

Aircraft type
Beechcraft 35
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
N129B
Operator
Unknown
Onboard fatalities
Unknown
Route
From Southern Wisconsin Regional Airport (JVL), Janesville, WITo C77
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 · descent
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
Airframe, component or system failure
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Empennage › Flutter

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

NTSB narrative

The pilot reported that he was cruising at 4,000 feet msl in clear sky conditions with smooth air, then he initiated a descent. He said that while descending through about 3,200 feet msl at 185 mph with a 5 degree nose down attitude and 15 degree left turn, the control yoke started oscillating fore and aft about 1/2 inch. The oscillations increased to about 1 inch fore and aft, and the airplane experienced 3 or 4 'solid jolts.' After about 5 seconds, the pilot reduced power, and the vibrations stopped. He continued to his destination and landed uneventfully. According to the Pilot Operating, the airplane's never exceed airspeed (Vne) was 202 mph. The maximum cruise airspeed (Vno), was 175 mph. Inspection of the airplane revealed that the aft fuselage received extensive damage between fuselage station (FS) 256.9 and the 233.5 bulkhead. The longerons were bent downward with a permanent 2.5 to 3 inch bend. The left and right side fuselage panels below the stabilizers exhibited 45 degree buckling from the bottom of the FS 256.9 bulkhead to forward of the stabilizer cuffs. The bottom fuselage panel forward of the 256.9 bulkhead had popped rivets and torn skin. There were three creases in the right stabilizer. No pre-existing cracks were found on the longerons. The ruddervators were properly balanced.

Probable cause

flutter for an undetermined reason, which resulted in structural damage to the aft fuselage.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record CHI98FA017
Event ID
20001208X08957
Case number
CHI98FA017
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: b30557fb09cc97cd3e807371bcb003f1113f236f5fa834eed9ad198f5ef819b2; retrieved 2026-09-22T18:24:51.900Z.