Robinson R44 accident near Alpine, Utah, May 17, 2019
On May 17, 2019 at about 4:34 pm local time, a 2005 Robinson R44 (helicopter), registered N744TW, was substantially damaged in an accident during enroute (cruise) near Alpine, Utah. It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
The noninstrument-rated pilot’s continued visual flight rules flight into instrument meteorological conditions, which resulted in spatial disorientation and subsequent loss of control. Contributing to the accident was hypoxia due to the high altitude at which the pilot chose to conduct the flight combined with the impairing effects of amphetamine use.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 17, 2019 · about 4:34 pm local time
- Place
- Alpine, Utah · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Robinson R44 II, built 2005 · all R44s on the register
- Registration
- N744TW · registry record · serial 10702
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The noninstrument-rated pilot and passenger departed in the helicopter on a visual flight rules (VFR) cross-country flight. A family member reported that it was raining at the time of the helicopter’s departure, and about an hour later, she received a video from the passenger depicting the helicopter flying above a cloud layer with no discernable horizon and some of the clouds extending above the helicopter’s altitude. Review of weather and flight track information revealed that the helicopter climbed to an altitude of about 13,000 ft mean sea level (msl); remaining about that altitude for over 25 minutes. About 3 minutes before the accident, the helicopter entered a descent that continued to an altitude of about 9,200 ft msl, during which the helicopter completed more than two 360° descending turns of decreasing radius. The last recorded location of the helicopter was about 1,650 ft from the accident site. The wreckage was highly fragmented, consistent with a high-speed impact. Examination of the airframe and engine revealed no evidence of any preaccident mechanical failures or malfunctions. The helicopter was approved by the manufacturer for day and night VFR flight, and was not approved for instrument flight. The helicopter was not equipped with a supplemental oxygen system, nor was any supplemental oxygen equipment found in the wreckage. AIRMET Sierra for mountain obscuration and moderate icing between the freezing level 18,000 ft was valid for the accident site at the accident time. There was no record of the pilot receiving any preflight weather information from an access-controlled source. The helicopter was likely operating in visual meteorological conditions above the clouds until its initial descent from about 13,000 ft, at which point the helicopter likely entered and remained in instrument meteorological conditions for the rest of the flight. Although the altitude and duration of the flight did not meet regulatory requirements for supplemental oxygen use, it is likely that the pilot may have been experiencing some early effects of hypoxia, including euphoria, which may have exacerbated the effects from his use of multiple drugs. Toxicology testing revealed a blood level of amphetamine (around 300 ng/ml) and the presence of phenylpropanolamine, indicating that the pilot was most likely using a street preparation of the drug. Testing also identified phenylpropanolamine and oxycodone in blood and urine, and oxazepam in urine. Euphoria and over-confidence associated with the pilot’s amphetamine use would have likely been exacerbated by the early effects of hypoxia due to his decision to operate the helicopter at high altitude. The pilot’s decision to operate the helicopter in reduced visibility conditions with no training in flight by reference to instruments in a helicopter that was not certified for instrument flight was conducive to the development of spatial disorientation. The helicopter’s turning descent before impact and the wreckage distribution that indicated a high-speed impact were both consistent with the known effects of spatial disorientation. Based on the available information, the pilot entered instrument meteorological conditions and shortly after, began experiencing spatial disorientation, which resulted in a loss of control and impact with terrain. It is likely that the psychoactive effects from the pilot’s use of amphetamine contributed to his preflight decision making, and the additional effects of early hypoxia contributed to his continued flight into adverse weather conditions.
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
- VFR encounter with IMC during enroute (cruise) defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
- Loss of control in flight during enroute (change of cruise level)
The NTSB's findings
- Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- Environmental issues › Conditions/weather/phenomena › Ceiling/visibility/precip › Low visibility › Contributed to outcome
- Personnel issues › Psychological › Perception/orientation/illusion › Spatial disorientation › Pilot
- Personnel issues › Physical › Impairment/incapacitation › Illicit drug › Pilot
- Personnel issues › Physical › Impairment/incapacitation › Hypoxia/anoxia › Pilot
- Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Pilot
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › (general) › Not attained/maintained
Pilot
- Certificate: private
- Ratings: rotorcraft: helicopter
- Flight time: 145.1 hours in all; 31.7 in this make and model; 30.7 in the last 90 days
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: rgt
- Injury: fatal
Passenger
- Seat: left
- Injury: fatal
The aircraft
- Airframe total time: 3,005.4 hours
- Last inspection: annual inspection, January 13, 2019; 68.8 hours since
- Maximum gross weight: 2,500 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming IO-540 SER (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: Ballard UT at 3:24 pm
- Destination: U42 West Jordan UT
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 170° at 7 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 3,100 ft
- Temperature: 46°F (8°C), dew point 37°F (3°C)
- Altimeter: 29.82 inHg
- Observation at 4:14 pm from KPVU, 17 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
10 documents, released by the NTSB on September 8, 2021. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Medical Factual Report | PDF, 4 pages | View Download |
| 2 | Weather Study | PDF, 15 pages | View Download |
| 3 | Interviews | PDF, 4 pages | View Download |
| 4 | Google Earth Flight Route | map file | Download |
| 5 | Airframe and Engine Exam | PDF, 9 pages | View Download |
| 6 | Memo for Record Maintenance Records | PDF, 1 page | View Download |
| 7 | Memo for Record Autopsy | PDF, 1 page | View Download |
| 8 | Toxicological Report | PDF, 2 pages | View Download |
| 9 | Statement of Party Representatives to NTSB Investigation | PDF, 2 pages | View Download |
| 10 | Photos | PDF, 12 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
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.
