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WPR18LA197 · Beech 90 C90A

12 Jul 2018 · Tolani Lake, AZ, United States

Guardian Flight Beech 90 C90A · Accident: inflight upset en route

From Flagstaff Pulliam Airport (FLG) to Gallup Municipal Airport (GUP)

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Event

NTSB case
WPR18LA197
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
Unknown
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

Beech 90 C90A

Aircraft type
Beechcraft 90
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
N617MM
Onboard fatalities
Unknown
Route
From Flagstaff Pulliam Airport (FLG), Flagstaff, AZTo Gallup Municipal Airport (GUP), Gallup, NM
Aircraft age
About 18 years (built 2000)
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
Defining eventThe 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
Inflight upset
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

  • Not determined › Not determined

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

NTSB narrative

The pilot reported that the airplane was climbing in instrument meteorological conditions with light rain and with the autopilot engaged. The conditions were smooth with no turbulence and no known icing, although he had engaged all anti-icing systems. The airplane was climbing at 600 ft per minute at an airspeed of 130 kts from 17,000 ft to 19,000 ft. The pilot reported that he was working on an iPad when it stopped functioning. He said he was resetting the iPad when there was a hard control input to the left as the airplane was passing through about 17,500 ft. The airplane rolled left and pitched down as he attempted to regain control. The pilot reported the autopilot was fighting his control inputs during the event, and he disengaged it to affect the recovery. Onboard data equipment showed a steady increase in airplane pitch attitude and a steady decrease in airspeed before the upset. The airplane spiraled down, losing about 4,000 ft of altitude before the pilot regained control. The pilot manually flew the airplane to its destination and landed safely. The wings were substantially damaged.

Postaccident examination of the autopilot revealed no mechanical anomalies that would have precluded normal operation. The autopilot computer was removed and examined with no anomalies noted. Thus, the reason for the autopilot deviation could not be determined. It is likely that the pilot was distracted with resetting the iPad and thus did not adequately monitor the autopilot, which led to his delayed awareness of the autopilot deviation.

Probable cause

An autopilot deviation during climb for undetermined reasons, which resulted in an in-flight upset and loss of airplane control. Contributing to the accident was the pilot’s failure to adequately monitor flight systems due to a distraction.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record WPR18LA197
Event ID
20180712X02446
Case number
WPR18LA197
Dataset
full-current
Source SHA-256
5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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, cause areas. 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: 5fe3f94ac7e3232fa3878be514b1725468bb8538539f260ee98e490cfe1fd524; retrieved 2026-09-16T07:49:47.496Z.