- Date
- June 8, 2025, 12:20 local (17:20 UTC)
- Place
- Tullahoma, TN
- Injuries
- 6 serious, 15 uninjured
- Damage
- Substantial damage
- Phase of flight
- Takeoff
- Aircraft
- N166DHDehavilland DHC-6 Twin Otter
- Defining event
- Takeoff: Loss of engine power (partial)
- Weather
- Visual (VMC) · Day
- Status
- Investigation ongoing
- Investigation class
- Class 3
- NTSB office
- Eastern Region Aviation
- Parties
- TSB, FAA FSDO
- FAA report
- 20250608006759A
- Case key
- 200284
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Preliminary report
What NTSB knew early in the investigation. It may change in the final report.
On June 8, 2025, about 1220 central daylight time, a DeHavilland DHC-6 Twin Otter, N166DH, was involved in an accident near Tullahoma, Tennessee. The commercial pilot and five passengers were seriously injured, and 15 passengers were not injured. The flight was being conducted as a 14 Code of Federal Regulations Part 91 skydiving flight. The pilot was attempting to take off from runway 24 at the Tullahoma Regional Airport (THA), Tullahoma, TN. The accident flight was his fourth flight in the airplane that day. The pilot stated the takeoff was normal and he raised the flaps once the airplane was clear of obstacles. When the airplane was about 500 ft above the ground, the pilot noticed asymmetrical thrust on the engines while syncing the propellers. He said, “In the following seconds, I continued trying to sync the props and was getting unusual feedback in the controls. I didn’t notice any loss of power in the gauges, but something felt a miss.” The pilot lowered the nose of the airplane and saw the altitude level off, and airspeed decrease. The pilot determined that the left engine had lost power. He initiated “engine out procedures” and turned left, back to the airport to try and land on runway 36. The pilot could not remember if he secured the left engine; however, he did remember adding flaps as per the engine-out procedures. The pilot said he tried to maintain airspeed above the single-engine minimum control speed (Vmc), but the airplane continued to descend. The pilot was unable to make it back to the airport and chose to land in a field. There were two trees in the field that he was unable to avoid, and the airplane impacted the trees. The airplane came to rest upright, but the left wing, left engine and the tail section separated from the airframe, resulting in substantial damage. The right wing and engine remained secured to the airframe. There was no postimpact fire. The airplane wreckage was recovered and taken to a secure facility for further examination.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Aircraft
- Registration
- N166DH
- Reported as
- Dehavilland DHC-6 Twin Otter
- Category
- Airplane
- Serial number
- 66
- Built
- 1967
- Airframe hours
- 26,616
- Damage
- Substantial damage
- Flight
- Skydiving · Part 91
- Airworthiness certificate
- Standard, Normal
- Last inspection
- AAIP · September 10, 2024
- Airport
- THA · Tullahoma Rgnl/Wm Northern Fld, runway 06/24, 5,501 × 100 ft, asphalt
- Equipment
- Unknown
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 270° at 14 knots
- Visibility
- 10 statute miles
- Temperature
- 81 °F, dew point 64 °F
- Altimeter
- 29.86 inHg
- Observed at
- KTHA
- METAR
- METAR KTHA 081735Z AUTO 27014KT 10SM FEW038 FEW044 SCT055 27/18 A2986
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.
Other investigations on N166DH · 1
Matched to the same aircraft by N-number and date.