(Originally published on FireAviation, September 14, 2018. Updated at 7:43 MDT September 14, 2018)
The California Department of Forestry and Fire Protection (CAL FIRE) has released what they call a “Green Sheet” report about the fatality and injuries that were caused by falling tree debris resulting from an air tanker’s retardant drop. The accident occurred on the Ranch Fire which was part of the Mendocino Complex of Fires east of Ukiah, California. The report was uploaded to the Wildland Fire Lessons Learned Center on September 13, 2018 exactly one month after the August 13 accident.
A firefighter from Utah, Draper City Battalion Chief Matthew Burchett, was killed when a low drop uprooted an 87-foot tall tree that fell on him. Three other firefighters had different assortments of injuries from sheered-off trees and limbs, including broken ribs, deep muscle contusions, ligament damage to extremities, scratches, and abrasions.
Standard procedure is for firefighters to leave an area before an air tanker drops. The report said the personnel on that Division were told twice that day to not be under drops — once in a morning Division break-out briefing, and again on the radio before the fatal drop and three others from large air tankers were made in the area. It was not confirmed that all supervisors heard the order on the radio to evacuate the drop area.
One of the “Incidental Issues / Lessons Learned” in the report mentioned that some firefighters like to record video of air tanker drops:
Fireline personnel have used their cell phones to video the aerial retardant drops. The focus on recording the retardant drops on video may distract firefighters. This activity may impair their ability to recognize the hazards and take appropriate evasive action possibly reducing or eliminating injuries.
The air tanker that made the drop was T-944, a 747-400 that can carry up to 19,200 gallons. Instead of a more conventional gravity-powered retardant delivery system, the aircraft has pressurized equipment that forces the retardant out of the tanks using compressed air. This is similar to the MAFFS air tankers. When a drop is made from the recommended height the retardant hits the ground as a mist, falling vertically, rather than the larger droplets you see with a gravity tank.
In this case, according to the report, the drop was made from approximately 100 feet above the tree tops. The report stated:
The Aerial Supervision Module (ASM) identified the drop path to the VLAT by use of a smoke trail. The VLAT initiated the retardant drop as identified by the smoke trail. Obscured by heavy vegetation and unknown to the VLAT pilot, a rise in elevation occurred along the flight path. This rise in elevation resulted in the retardant drop only being approximately 100 feet above the treetops at the accident site.
When a drop is made from a very low altitude with any air tanker, the retardant is still moving forward almost as fast as the aircraft, as seen in this drop. If it is still moving forward there will be “shadows” that are free of retardant on the back side of vegetation, reducing the effectiveness of the drop. From a proper height retardant will gradually slow from air resistance, move in an arc and ideally will be falling gently straight down before it hits the ground. Another example of a low drop was on the Liberty Fire in Southern California in 2017 that dislodged dozens of ceramic roofing tiles on a residence and blew out several windows allowing a great deal of retardant to enter the home.
We reached out with some questions to Global Supertanker, the company that operates the 747 Supertanker, and they gave us this statement:
We’re heartbroken for the families, friends and colleagues of Chief Burchett and the other brave firefighters who were injured during their recent work on the Mendocino Complex Fire. As proud members of the wildland firefighting community, we, too, have lost a brother.
On August 13, 2018, Global SuperTanker Services, LLC acted within procedural and operational parameters. The subject drop was initiated at the location requested by the Aerial Supervision Module (ASM) after Global SuperTanker Services, LLC was advised that the line was clear.
The former President and CEO of the company, Jim Wheeler, no longer works there as of September 1, 2018. The company is owned by Alterna Capital Partners LLC, of Wilton, Conn.
(Updated at 7:43 MDT September 14, 2018 to include the statement from Global Supertanker that we received at 7:35 p.m. MDT September 14, 2018)
