Leonardo AW139 accident near Tujunga, California, September 2, 2017
On September 2, 2017 at about 4:48 pm local time, a 2017 Leonardo AW139 (helicopter), registered N304FD, was substantially damaged in an accident during maneuvering (low-alt flying) near Tujunga, California. It was a public-use flight (local) under public-use (government) rules. No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A yaw excursion and uncontrolled descent due to loss of tail rotor effectiveness during aerial firefighting operations resulting in an impact with trees. A contributing factor was the pilot’s failure to maintain sufficient airspeed, coupled with a quartering tailwind during aerial firefighting operations. An additional factor was the operator’s lack of guidance to the hazards associated with aerial firefighting operations near and around smoke columns.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 2, 2017 · about 4:48 pm local time
- Place
- Tujunga, California · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Leonardo AW139, built 2017
- Registration
- N304FD · registry record · serial 41528
- Damage
- Substantial damage
- Flight
- Public-use flight (local) · public-use (government) rules
The NTSB's narrative final · quoted from the NTSB record
The pilot of the Los Angeles Fire Department (LAFD) helicopter was conducting a water drop during an aerial firefighting mission when the accident occurred. As the helicopter neared the drop area, the pilot slowed to about 20 knots and the helicopter entered an uncommanded right yaw and began to descend. The pilot released the water and the helicopter continued to yaw to the right and descend rapidly. The pilot reported that he had little positive control of the helicopter, and the helicopter contacted trees. After the tree impacts, which resulted in substantial damage to the horizontal stabilizers and tail boom, the pilot regained control, departed the area, and performed an emergency landing nearby. The pilot reported, and onboard data from the helicopter confirmed, that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. During the water drop, it is likely that the helicopter encountered radiant heat from the fire and its associated smoke columns, which reduced helicopter performance. Additionally, the helicopter was operating with a quartering tailwind at the time, which was within the critical wind azimuth published by the manufacturer. It is likely that the combination of the increased heat and smoke, adverse wind conditions, a higher helicopter weight due to the water onboard, and the higher torque demand as the result of the helicopter's slower airspeed resulted in the yaw excursion and vertical descent due to a loss of tail rotor effectiveness. As the helicopter continued its flight path out of the area of the gases, heat, and wind, and dropped the water, the pilot was able to regain control of the helicopter. Review of published LAFD training information and operating procedures revealed no guidance regarding water drop operations or the hazards associated with operating near and around smoke columns.
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
- Miscellaneous/other during maneuvering (low-alt flying) defining event
- Loss of control in flight during maneuvering (low-alt flying)
- Attempted remediation/recovery during maneuvering (low-alt flying)
- Collision with terrain or object (not controlled flight into terrain) during maneuvering (low-alt flying)
The NTSB's findings
- cause Environmental issues › Conditions/weather/phenomena › Wind › Tailwind › Effect on equipment
- cause Environmental issues › Conditions/weather/phenomena › Temp/humidity/pressure › High temperature › Effect on equipment
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Descent/approach/glide path › Attain/maintain not possible
- factor Organizational issues › Management › Culture › Standard operating practices › Operator
- factor Organizational issues › Support/oversight/monitoring › Oversight › Oversight of operation › Operator
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 5,500 hours in all; 545 in this make and model; 51 in the last 90 days; 16 in the last 30 days; 5,400 as pilot in command
- Last flight review: January 25, 2017
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: no injuries
Other crew
- Certificate: flight instructor, commercial pilot
- Ratings: instructor: helicopter; instructor: instrument helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 1,265 hours in all; 12 in this make and model; 56 in the last 90 days; 18 in the last 30 days; 1,202 as pilot in command; 208 on instruments
- Last flight review: August 23, 2017
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 121.9 hours
- Last inspection: continuous airworthiness programme, September 2, 2017
- Maximum gross weight: 15,432 lb
- Seats: 6
- Landing gear: retractable
- Engine 1: Pratt & Whitney Canada PT6C-67C (turboshaft); 122 hours total
- Engine 2: Pratt & Whitney Canada PT6C-67C (turboshaft); 122 hours total
- Operator: Los Angeles Fire Department
The flight
- Departed from: VNY Van Nuys CA at 3:30 pm
- Destination: Tujunga CA
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 120° at 8 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 3,900 ft
- Temperature: 91°F (33°C), dew point 61°F (16°C)
- Altimeter: 29.82 inHg
- Observation at 4:53 pm from KBUR, 4 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
9 documents, released by the NTSB on January 14, 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 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 13 pages | View Download |
| 2 | N304FD Fire 4 Weight and Balance Documents | PDF, 20 pages | View Download |
| 3 | Cockpit Voice Recorder - Specialist's Factual Report | PDF, 4 pages | View Download |
| 4 | Honeywell EGPWS Mkxxii Factual Report | PDF, 4 pages | View Download |
| 5 | Leonardo Penny & Giles Mpfr Factual Report | PDF, 30 pages | View Download |
| 6 | Interagency Aviation Accident Prevention Bulletin 18-02 Smoke Column Hazards | PDF, 2 pages | View Download |
| 7 | N304FD Fire 4 Post Accident Flight Video (Courtesy of the Lafd) | MOV file | Download |
| 8 | Statement of Party Representatives to NTSB Investigation | PDF, 3 pages | View Download |
| 9 | Accident Photographs | PDF, 8 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.