Curtiss Wright TRAVEL AIR 4000 accident near Palmer Lake, Colorado, March 2, 2016
On March 2, 2016 at about 3:00 pm local time, a 1928 Curtiss Wright TRAVEL AIR 4000, registered N6464, was destroyed in an accident during enroute (cruise) near Palmer Lake, Colorado. It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
The pilot's failure to maintain sufficient airspeed while maneuvering at low altitude in strong gusting winds, which resulted in exceedance of the airplane's critical angle of attack and an aerodynamic stall/spin. Contributing to the accident was the pilot's impairment due to the effects of a sedating antihistamine.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 2, 2016 · about 3:00 pm local time
- Place
- Palmer Lake, Colorado · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Curtiss Wright TRAVEL AIR 4000 NO SERIES, built 1928 · all TRAVEL AIR 4000s on the register
- Registration
- N6464 · registry record · serial 785
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The commercial pilot and the pilot-rated passenger were flying the biplane to a fly-in gathering in another state. Witnesses saw the airplane flying over a frozen lake at a low altitude and low airspeed. One witness saw the airplane "listing" left and right before it entered a left turn, and he lost sight of it. Other witnesses saw the airplane turn left and nose-dive into the ground. A postimpact fire consumed most of the airplane. Damage to the wreckage indicated that the airplane impacted the ground in a nose-down attitude. The examination did not reveal evidence of any preimpact anomalies with the airframe, engine, or the control system of the airplane. A witness reported that, at the time of the accident, the wind was from the south about 30 miles per hour. However, a burnt area extending east from the airplane's impact point indicated the wind was from the west. Additionally, although wind information from nearby weather stations varied in direction and intensity. One station, about 14 miles west-northwest of the accident site reported calm wind., However, another station, located about 11 miles south of the accident site, recorded wind from the west at 11 knots with gusts to 27 knots about the time of the accident and wind from the west at 33 knots with gusts to 48 knots about an hour after the accident. Further, the forecast for the accident area called for wind gusts to 40 knots from the west-northwest. Therefore, it is likely that strong gusty west winds prevailed in the accident area at the time of the accident. Although some witnesses speculated that the pilot may have been attempting to land the airplane on the frozen lake, the airplane was not equipped to land on ice, and the reason the pilot was maneuvering at a low altitude in strong gusty winds could not be determined. Based on the witness observations and the damage to the wreckage, it is likely that the pilot allowed the airspeed to decrease to a point where the critical angle of attack was exceeded, and the airplane entered an aerodynamic stall/spin. Although the pilot was known to have heart disease, it is unlikely that his medical condition contributed to the accident. The witness observations indicate that the pilot was actively flying the airplane before the loss of control. Toxicology testing showed the presence of chlorpheniramine in the pilot's blood at a level that was likely in the therapeutic range. Chlorpheniramine is a sedating antihistamine available in a number of over the counter products, and it carries the warning, "May impair mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving, operating heavy machinery)." Because of its sedating effect, chlorpheniramine may slow psychomotor functioning and cause drowsiness. It has also been shown in a driving simulator (after a single dose) to suppress visual-spatial cognition and visual-motor coordinating functions when compared to placebo. Such functions would have been necessary for the pilot to maintain control of the airplane while maneuvering close to the ground in the strong gusty wind conditions. Therefore, it is likely that the pilot's ability to safely operate the plane was impaired by the effects of chlorpheniramine.
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 enroute (cruise) defining event
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Airspeed › Not attained/maintained
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Capability exceeded
- factor Personnel issues › Physical › Impairment/incapacitation › OTC medication › Pilot
- cause Environmental issues › Conditions/weather/phenomena › Wind › High wind › Effect on operation
- cause Environmental issues › Conditions/weather/phenomena › Wind › Gusts › Effect on operation
Pilot
- Certificate: commercial pilot, private
- Ratings: multi-engine land; single-engine land
- Flight time: 5,000 hours in all
- Medical certificate: Class 3 (waiver time limited special)
- Seat: rear
- Injury: fatal
The aircraft
- Last inspection: annual inspection, July 1, 2015
- Maximum gross weight: 2,702 lb
- Seats: 2
- Landing gear: fixed
- Engine: Wright J-6 (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: LMO Longmont CO at 2:15 pm
- Destination: CGZ Casa Grande AZ
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 080° at 12 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 12,000 ft
- Temperature: 48°F (9°C), dew point 16°F (-9°C)
- Altimeter: 29.87 inHg
- Observation at 2:54 pm from COS, 20 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
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.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number CEN16FA116.
