SEA96MA043 · Mitsubishi MU-2B-36
Pro Air Services of Salt Lake Mitsubishi MU-2B-36 · Accident: in flight encounter with weather en route
From Salt Lake City International Airport (SLC) to Pocatello Regional Airport (PIH)
Event
- NTSB case
- SEA96MA043
- 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
- 8 · 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
Mitsubishi MU-2B-36
- Aircraft type
- Mitsubishi MU-2
- 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
- N693PA
- Operator
- Pro Air Services of Salt Lake
- Onboard fatalities
- Unknown
- Route
- From Salt Lake City International Airport (SLC), Salt Lake City, UTTo Pocatello Regional Airport (PIH), Pocatello, ID
- 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
- 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
- Airframe › Ice
- Flightcrew › Airspeed, not maintained
- Flightcrew › Flight into adverse weather, continued
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
A Mitsubishi MU-2 departed Salt Lake City, Utah, and climbed to 16,000 feet MS on an IFR flight to Pocatello, Idaho. While in cruise flight, the MU-2 encountered structural icing conditions. According to radar data, the MU-2 began slowing from a cruise speed of about 190 knots with slight deviations from heading and altitude. The airspeed decreased to about 100 knots, and the flight crew declared an unspecified emergency, then radio contact was lost. The MU-2 began a right turn, then it entered a steep descent and crashed. The pilot of a Beech 1900 (about 12 minutes in trail of the MU-2), stated that he encountered moderate rime icing at 16,000 feet. The Beech pilot activated his deice boots (3 times) and descended to 12,000 feet to exit the icing conditions. The MU-2 flight manual warned that during flight in icing conditions, stall warning devices may not be accurate and should not be relied upon; and to minimize ice accumulation, maintain a minimum cruise speed of 180 knots or exit the icing conditions. An investigation determined that the captain of the MU-2 was aware of deficiencies in the timer for the deice boots, as well as other maintenance deficiencies. The captain's medical certificate was dated 11/17/94; he was providing executive transportation for compensation under an agreement for "contractual flights," under 14 CFR 91. Although icing conditions were forecast in the destination area, no icing was forecast for the en route portion of the flight.
Probable cause
continued flight by the flightcrew into icing conditions with known faulty deice equipment; structural (airframe) ice; and failure of the flight crew to maintain adequate airspeed, which resulted in the loss of aircraft control and collision with terrain. A factor relating to the accident was: the en route weather (icing) condition, which was not forecast (inaccurate forecast).
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA96MA043
- Event ID
- 20001208X05205
- Case number
- SEA96MA043
- 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: 3945f48e5035cacf542f3c6393110cf06877228dc3bea9d596a16027dcbd10ca; retrieved 2026-09-20T23:27:25.094Z.