Robinson Helicopter Company R44 II and DJI AIR IIS mid-air collision near Palmer, Alaska, October 10, 2021
On October 10, 2021 at about 9:20 pm local time, 2 aircraft, Robinson Helicopter Company R44 II (N555EL) and DJI AIR IIS (FA3P4CAK37), were involved in a mid-air collision near Palmer, Alaska. No one was hurt; 5 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The unmanned aircraft pilot’s failure to yield the right of way to the helicopter.
The unmanned aircraft pilot’s failure to yield the right of way to the helicopter.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 10, 2021 · about 9:20 pm local time
- Place
- Palmer, Alaska · map
- Type
- Accident · mid-air collision
- Injuries
- No one was hurt; 5 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft 1
- Robinson Helicopter Company R44 II, built 2005
- Registration
- N555EL · registry record · serial 10665
- Damage
- Substantial damage
- Flight
- Aerial observation flight · charter and air-taxi rules (Part 135)
- Aircraft 2
- DJI AIR IIS
- Registration
- FA3P4CAK37 · no longer on the register · serial 3YTSJ4T0030A8A
- Damage
- Destroyed
- Flight
- Personal flight · small-drone rules (Part 107)
The NTSB's narrative for the Robinson Helicopter Company R44 II final · quoted from the NTSB record
The pilot of the helicopter reported that, while conducting an air tour flight he made about a 90° right turn near a scenic area, when he heard a faint “ting” sound. He stated that there was no indication of a mechanical failure or malfunction and the helicopter continued to operate normally, so he continued the flight. After shutdown he noticed damage to one of the main rotor blades and concluded that the helicopter had collided with an uncrewed aerial vehicle (UAV). The helicopter sustained substantial damage to the main rotor blade. The pilot of the unmanned aircraft system (UAS) reported that while flying his UAV near a scenic area a red helicopter suddenly appeared and collided with the UAV. 14 CFR Part 107.37 Operations near aircraft, right of way rules, states in part: (a) Each small unmanned aircraft must yield the right of way to all aircraft, airborne vehicles, and launch and reentry vehicles. Yielding the right of way means that the small unmanned aircraft must give way to the aircraft or vehicle and may not pass over, under, or ahead of it unless well clear. (b) No person may operate a small unmanned aircraft so close to another aircraft as to create a collision hazard.
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 NTSB's narrative for the DJI AIR IIS final · quoted from the NTSB record
The pilot of the helicopter reported that, while conducting an air tour flight he made about a 90° right turn near a scenic area, when he heard a faint “ting” sound. He stated that there was no indication of a mechanical failure or malfunction and the helicopter continued to operate normally, so he continued the flight. After shutdown he noticed damage to one of the main rotor blades and concluded that the helicopter had collided with an uncrewed aerial vehicle (UAV). The helicopter sustained substantial damage to the main rotor blade. The pilot of the unmanned aircraft system (UAS) reported that while flying his UAV near a scenic area a red helicopter suddenly appeared and collided with the UAV. 14 CFR Part 107.37 Operations near aircraft, right of way rules, states in part: (a) Each small unmanned aircraft must yield the right of way to all aircraft, airborne vehicles, and launch and reentry vehicles. Yielding the right of way means that the small unmanned aircraft must give way to the aircraft or vehicle and may not pass over, under, or ahead of it unless well clear. (b) No person may operate a small unmanned aircraft so close to another aircraft as to create a collision hazard.
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 for the Robinson Helicopter Company R44 II from the NTSB's investigation tables, in plain English
What happened, in order
- Collision with terrain or object (not controlled flight into terrain) during maneuvering (low-alt flying) defining event
The NTSB's findings
- Personnel issues › Psychological › Attention/monitoring › Monitoring other aircraft › Pilot of other aircraft
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: instructor: helicopter; instructor: instrument helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,252 hours in all; 1,020 in this make and model; 106 in the last 90 days; 21 in the last 30 days; 1,188 as pilot in command; 389 on instruments
- Last flight review: June 7, 2021
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 3,760.4 hours
- Last inspection: 100-hour inspection, October 6, 2021
- Maximum gross weight: 2,500 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming IO-540-AE1A5 (piston); 3,760 hours total
- Operator: Pollux Aviation LTD
Weather at the time
- Light: daylight
- Wind: from 070° at 3 knots
- Visibility: 7 statute miles
- Sky: overcast at 2,500 ft
- Temperature: 39°F (4°C), dew point 37°F (3°C)
- Altimeter: 29.69 inHg
Weather report (METAR): PAAQ 100853Z AUTO 07003KT 7SM -RA OVC025 04/03 A2969 RMK AO2 SLP059 P0005 60013 T00440033 400830011 53023 TSNO
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 3 |
The factual record for the DJI AIR IIS from the NTSB's investigation tables, in plain English
The NTSB's findings
- Personnel issues › Psychological › Attention/monitoring › Monitoring other aircraft › Pilot
Pilot
- Medical certificate: Unknown
- Seat: none
- Injury: no injuries
The aircraft
- Last inspection: inspection type not recorded
- Landing gear: fixed
The flight
- Flight plan: none
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on July 21, 2022. 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 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Witness Statements | PDF, 3 pages | View Download |
| 3 | Photos | PDF, 3 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.