Tromsness Enterprises INC TURBINE LE accident near Miami, Oklahoma, April 28, 2008
On April 28, 2008 at about 7:30 pm local time, a Tromsness Enterprises INC TURBINE LE, an amateur-built aircraft,, registered N747CT, was destroyed in an accident during maneuvering near Miami, Oklahoma (Miami Municipal Airport). It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain control of the airplane for undetermined reasons. Contributing to the accident included his extensive use of medications and/or his multiple medical conditions and the failure of the FAA to follow up on his reported medication use.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 28, 2008 · about 7:30 pm local time
- Place
- Miami, Oklahoma · Miami Municipal Airport · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Tromsness Enterprises INC TURBINE LE, amateur-built
- Registration
- N747CT · registry record · serial 137T
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
Shortly after departure, the single-engine, turbo propeller equipped airplane was observed in a spiraling descent before it impacted the center median of a major interstate and exploded. An on-scene examination of the airplane revealed that the only identifiable parts of the airplane that remained were the propeller, the engine, a flap, a section of the vertical stabilizer, the elevator, the landing gear and both wing spars. The three-bladed propeller remained attached to the engine; however, one blade had separated from the hub. Examination of the blades revealed that they were curled aft, exhibited leading edge damage and deep gouging from impact with the concrete barrier. The pilot had a history of anxiety, depression, muscle pain, severe headaches, obstructive sleep apnea (OSA), and memory loss, and had recently and regularly been using multiple prescription medications, including three medications for pain, two antidepressants, and a sleep aid, each of which had the potential to adversely affect performance. The pilot was likely suffering from medication-overuse headache, in which overly frequent use of pain medications to control intermittent migraine or tension headaches over time results in a continuous or very frequently recurring headache; his medication combination may have substantially increased his risk for seizure activity; and his OSA may have raised the likelihood of accident involvement. The pilot had not admitted to most of the medications he was using or the medical conditions with which he had been diagnosed on his applications for airman medical certificate, though on one application the pilot had indicated occasional use of a prescription pain medication, and no additional detail was pursued by the FAA.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Loss of control in flight during maneuvering defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- factor Personnel issues › Physical › Impairment/incapacitation › Prescription medication › Pilot
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › (general) › Not attained/maintained
- factor Personnel issues › Physical › Health/Fitness › (general) › Pilot
- factor Organizational issues › Support/oversight/monitoring › Oversight › Oversight of personnel › FAA/Regulator
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 3,012 hours in all
- Medical certificate: Class 3
- Seat: unk
- Injury: fatal
The aircraft
- Last inspection: inspection type not recorded
- Seats: 2
- Landing gear: retractable
- Engine: (turboprop); 0 hours total
- Fire on the ground
- Operator: Tromsness Enterprises INC
The flight
- Departed from: MIO Miami OK
- Flight plan: none
Weather at the time
- Wind: from 330° at 11 knots, gusting 15
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 63°F (17°C), dew point 41°F (5°C)
- Altimeter: 30.12 inHg
- Observation at 2:32 pm from GMJ
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.