10 Tanker Air Carrier: I drop in on the company that drops on fires

Article and Photos by Matt Shinavar

10 Tanker operates a pair of DC-10s which have been modified to enable water or retardant to be dropped on forest fires.  When fires get out of hand, nobody calls Ghostbusters; rather, the phone at 10 Tanker rings.  From the time the phone rings 11,600 gallons of water, foam, gel, or retardant can start barreling down the runway 24 minutes later, and they’ve done it before.

The two air tankers started life with the airlines and were saved from a certain date with the scrapper.  The modification from DC-10 to air tanker takes about 6 months; to get the first aircraft fighting fires took slightly longer.  The first step was to demonstrate to the FAA the modifications to the airframe did not adversely impact the structural integrity or flying qualities of the aircraft.  The FAA granted a standard airworthiness certificate for the airplanes, rather than an experimental or restricted certificate.  It was demonstrated carrying 100,000 lbs of water under the fuselage was not any more stressful to the airframe, however strain is still measured every flight just to be safe.  The other important factor was to work with Boeing to determine a maintenance schedule which adequately met the needs of 10 Tanker and their mission profiles.  The next important step was to merit a Part 137 air operator’s certificate which would allow 10 Tanker to dispense material from their aircraft – otherwise legally dropping retardant would be decidedly difficult.  A Part 137 AOC was issued March of 2006.  The last step, and debatably the most important, was IATB approval.  The Interagency Air Tanker Board is the governing board for air tankers which oversees the testing of air tankers to determine how effective air tankers are at fighting fires.  The testing to gain IATB certifications required one airplane with full load and lots of little plastic cups; eight football fields worth, in 10’ x 10’ squares.  The testing performed for IATB validated coverage levels 2-8 – how many gallons per 100 square feet the tanker can drop.

11,600 gallons is a difficult number to imagine.  It works out to a line that is three quarters of a mile long, 50 feet wide dropped from 200-500 feet at 150 knots.  A full load of 11,600 gallons weighs nearly 100,000 lbs which seems a hazard to firefighters that may be on the ground when a line is laid.  10 Tanker performed some less than official testing which might ease the minds of firefighters; a pop up shade tent and lawn chairs were setup in the path of the oncoming tanker, with only the lawn chairs knocked over and the tent unaffected after the drop.  The tank system is all external to the airframe, an up-scaled version of the tanks found on Erickson’s Air Cranes.  The tank doors are constant feed, gravity fed, and can be started and stopped on command.

10 Tanker has flown on 420+ missions, on 70+ fires, in 6 states, in 3 countries and have been told they are “highly effective in suppressing [fire] movement.”  The internal record for missions in a day is 9; being flown in only 4.5 hours of flight time.  10 Tanker has received permission to hot refuel and hot refill the aircraft, shutting down only the left engine where the hoses are attached to the tanks, to significantly reduce the amount of time the aircraft is required to be on the ground while fighting fires.  While the aircraft was temporarily based at McClellan Airport near Sacramento, the aircraft serviced 4 states in 19 missions, taking advantage of the speed and payload capabilities of the DC-10.  Carrying the external tank does impose a flight speed restriction, but it is only 30 knots below the manufacturer recommended cruise speed and generally does not impact firefighting ability.  One fire that 10 Tanker responded to was a small brush fire located on a nature preserve.  10 Tanker was directed to drop a line to prevent the fire from spreading deeper into the nature preserve.  After the line was dropped, the incident commander told them to return to base, reload, and return to the fire, which the aircraft responded they had nearly 70% of the load left.  The incident commander, thinking on his feet, requested two more lines with the remaining load to completely surround the fire in a triangle shape.  The fire burnt itself out.  If there is a brush fire that is 10-15 acres, the DC-10 can put it out with one load by itself.

After spending a couple hours going through the brief of 10 Tanker’s capabilities and track record, Rick Hatton – owner of 10 Tanker – asked if we wanted to watch a water drop, go for a ride, or both.  Hopefully at that point I didn’t make too embarrassing a sound or face.  Of course I would like to go for a ride on the DC-10, a once in a lifetime experience.  Vicki, the nickname given to Tanker 911 when performing firefighting activities in Australia, was going to take us for a ride.

The tanker, while stripped to the insulation in the back, looks direct from the factory in the cockpit.  The only modifications are the tank volume meters and door controls.  The aircraft took a full load up, the plan being to drop just to the side of Victorville’s crosswind runway – first a dry run and then two drops at a half load each.  The aircraft handled like a hotrod through the pattern; 100,000 lbs of water slung under the fuselage.  Despite dropping 50,000 lbs of water in only three seconds, there were no sounds in the cockpit, no radical pitch changes, and no radical altitude change.  Other than hearing the pilot give the drop command and see the flight engineer push the drop button, there was almost no indication we were dropping all that water below us.  Flying through the pattern with 10 Tanker was an awesome experience – thanks Rick!

After landing, there were some sunset pictures taken of Tanker 910 and I wandered through 10 Tanker’s facilities.  One of the buildings is a former hush house where F-4’s had their engines run up; Rick’s Lancair Legacy was also parked in the corner of the former hush house.  Rick is an airplane guy to the core, he was more than excited to talk about his Legacy build; from the engine he sourced, the weight watching he did, the minor changes he made throughout to make his Legacy unique, and even talking through balancing the ailerons.  As a whole, the crew at 10 Tanker is dedicated to their mission and really seems to take pride in the work they do.  I cannot thank the people at 10 Tanker enough for the hospitality and generosity I was shown on my day there.


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