CHI94FA155 · Maule M-7-235
Maule M-7-235 · Accident: in flight encounter with weather en route
From Aberdeen Regional Airport (ABR) to Miles City Airport - Frank Wiley Field (MLS)
Event
- NTSB case
- CHI94FA155
- 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
Maule M-7-235
- Aircraft type
- Maule M-7
- 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
- N525GS
- Operator
- Sperber, Eugene J. · private individual
- Onboard fatalities
- Unknown
- Route
- From Aberdeen Regional Airport (ABR), Aberdeen, SDTo Miles City Airport - Frank Wiley Field (MLS), Miles City, MT
- 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
- Visual flight rules (VFR) flight into instrument meteorological conditions (IMC)
- 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 › Altitude, not maintained
- Pilot in command › VFR flight into imc, performed
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
AT 1635 CDT ON 5/1/94 & AT 0319 CDT ON 5/2/94, THE NON-INSTRUMENT RATED PILOT CONTACTED THE GREEN BAY FLIGHT SERVICE STATION (FSS) & GOT WEATHER INFO FOR A FLIGHT FROM GREEN BAY, WI, TO MILES CITY, MT. HE WAS ADVISED THAT VFR CONDITIONS WERE EXPECTED ALONG HIS ROUTE OF FLIGHT, WITH A POSSIBILITY OF SHOWERS INCREASING AS HE NEARED HIS DESTINATION. AFTER TAKEOFF, HE CONTACTED THE PRINCETON & HURON FSS'S & OBTAINED WINDS & AN ABBREVIATED WEATHER BRIEFING FOR THE ROUTE TO ABERDEEN, SD. AT ABOUT 0800, AN EN ROUTE STOP WAS MADE IN VFR CONDITIONS AT ABERDEEN TO REFUEL. THE PILOT DEPARTED AT ABOUT 0900 WITHOUT UPDATING HIS WEATHER INFO. NEAR MCINTOSH, SD, WITNESSES OBSERVED THE AIRPLANE FLYING LOW IN POOR WEATHER CONDITIONS (LOW CLOUDS & FOG). SUBSEQUENTLY, IT IMPACTED RISING TERRAIN. ABOUT 10 DAYS LATER, IT WAS LOCATED PARTIALLY SUBMERGED IN A POND. NO PREIMPACT PART FAILURE OR MALFUNCTION WAS FOUND. AT 0745 ON 5/2/94, AN AIRMET WAS ISSUED TO WARN OF OCCASIONAL LOW CEILINGS & VISIBILITIES WITH PRECIPITATION & FOG FROM TEXAS THROUGH THE DAKOTAS.
Probable cause
VFR FLIGHT BY THE NON-INSTRUMENT RATED PILOT INTO INSTRUMENT METEOROLOGICAL CONDITIONS (IMC), AND HIS FAILURE TO MAINTAIN SUFFICIENT ALTITUDE (OR CLEARANCE) FROM RISING TERRAIN. FACTORS RELATED TO THE ACCIDENT WERE: FAILURE OF THE PILOT TO UPDATE HIS WEATHER INFORMATION AT THE EN ROUTE STOP, THE ADVERSE WEATHER CONDITIONS, RISING TERRAIN, AND THE PILOT'S LACK OF INSTRUMENT EXPERIENCE.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI94FA155
- Event ID
- 20001206X01225
- Case number
- CHI94FA155
- 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: 59da003b48cbb68bf48925f084a9c9b2cca583e96a279611733498aa8c96d9ca; retrieved 2026-09-21T00:10:42.606Z.