CHI93FA378 · Aero Commander 690A
Midwest Flying Service Aero Commander 690A · Accident: airframe, component or system failure en route
From an unrecorded airport to Battle Creek Executive Airport at Kellogg Field (BTL)
Event
- NTSB case
- CHI93FA378
- 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
- 2 · 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
- Instrument Meteorological Cond
Aero Commander 690A
- Aircraft type
- Aero Commander 690
- 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
- N242TC
- Operator
- Midwest Flying Service
- Onboard fatalities
- Unknown
- Route
- From not recordedTo Battle Creek Executive Airport at Kellogg Field (BTL), Battle Creek, MI
- 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 · climb to 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
- 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
- Destroyed
Cause areas
- Pilot in command › Aircraft control, not maintained
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE AIRPLANE DEPARTED IN IMC CONDITIONS ON AN IFR FLIGHT PLAN. SHORTLY AFTER TAKEOFF THE PILOT TOLD THE DEPARTURE CONTROLLER HE HAD '...A PROBLEM.' THE AIRPLANE'S FLIGHT PATH WAS A SERIES OF LEFTHAND TURNS WHILE PERFORMING DESCENTS AND ASCENTS. REPORTS OF ENGINE SOUNDS VARIED FROM HIGH RPM TO LOW RPM. MANY WITNESSES REPORTED THE AIRPLANE DESCENDING OUT OF, AND CLIMBING INTO, CLOUDS. THE AIRPLANE WAS OBSERVED IN A 45 DEGREE ANGLE DESCENT, RIGHT WING LOW, AS IT COLLIDED WITH TREES AND THE GROUND. THE ON-SCENE INVESTIGATION FOUND AN INTERMITTENT ELECTRIC GYRO SYSTEM INVERTER, A BROKEN FILAMENT ON THE INVERTER POWER 'OUT' LIGHT BULB, ELECTRICALLY POWERED GYRO'S ROTORS DID NOT HAVE ROTATIONAL DAMAGE, AND A VACUUM POWERED ATTITUDE INDICATOR ROTOR WITH ROTATIONAL DAMAGE. THE PILOT'S TOXICOLOGY REPORT STATED 45 MG/DL OF ETHANOL DETECTED IN HIS MUSCLE TISSUE.
Probable cause
was the pilot-in-command not maintaining aircraft control during the intermittent operation of the electrically operated attitude gyro. Factor's associated with this accident are an fluctuating (intermittent) electrical system inverter and the pilot-in-command not performing remedial action by using the vacuum powered attitude gyro and other flight instruments once the airplane was making a series of climbs, descents, and heading changes.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI93FA378
- Event ID
- 20001211X13360
- Case number
- CHI93FA378
- 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: 312864f8d303761aa05d1e31a799622e2a6dc20af61f3bd7ca23bf62556cc70b; retrieved 2026-09-21T00:22:28.243Z.