Evaluations of Tanker 911, one of the DC-10 very large air tankers

Tanker 911 dropping Poco Fire
Tanker 911 dropping on the Poco Fire in Arizona, 2012. Photo by Ian James.

We have seen the written evaluations of Tanker 911, one of the DC-10 very large air tankers, for some of the retardant drops the aircraft completed on fires in Arizona and Utah in June and July. The forms were signed by individuals identifying themselves as lead plane pilots.

The evaluation form consists of two parts; a narrative section, and assigning a grade for specific aspects of performance: Reload Turn Times, Maneuverability, Steep Terrain Operations, Drop Patterns, and Uniformity of Coverage. All of the grades were “Above Average” or “Exceeded Expectation”.

Here are the details that were hand written in the narrative section on the forms:

Poco Fire, Phoenix, Arizona; Gallons Delivered 11,700 x 6; June 16-19, 2012

  • Six loads
  • All drop patterns were good and uniform. Flat and steep terrain – excellent performance in all profiles.
  • CL [Coverage level] 6 utilized in timber and mixed brush.
  • Quantity and mass of load delivered allowed for higher than standard drop altitudes to minimize exposure in challenging terrain and still achieve good pattern on the ground.
  • Quantity delivered also means 1 pass, 1 exposure instead of 7 from a legacy platform carrying 2,000 gallons!
  • Very uniform and consistent pattern on the ground. Very accurate starts. Performed some split loads as needed.


Fox Fire, Tucson, Arizona; Gallons Delivered 11,700 x 2; 2 loads; 3 drops; June 18, 2012

  • 1 – CL 6 – Split Load – Started and stopped to tie in a road in front of structures. Very accurate start and stop. Last 2,000 gal reinforced first drop.
  • 2 – CL 4 – One drop. Excellent coverage! It would have taken 6 or 7 loads from a legacy platform to get same length of line.
  • Quick effective line production.


Six Shooter Fire, Globe, Arizona; Gallons Delivered 11,700; 1 load; 8 drops; June 17, 2012

  • This was an initial attack fire. The location of this 5-acre fire, 1,500 to 2,000 ft below a ridge line, necessitated a substantial decent profile to get over the target on speed and altitude. The DC-10 was very capable and provided excellent coverage on and around the entire fire. The fire was successfully stopped at the same perimeter when the tanker dropped!
  • Excellent drops and performance.


Shingle Fire, Cedar City, Utah; Gallons Delivered 11,700 x 4; 4 loads; July 2-3, 2012

  • CL 6
  • Good coverage and line production. Excellent pattern on the ground and saved lots of time vs utilizing smaller aircraft. We would not have been able to get the line needed done without this tool.
  • Long turn arounds loading at [illegible; looked like “IVA”, “IWA”, or “IUA”]. 2 hour flights but dollars/gal still comperable considering speed and gallons!


Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire. Google+

13 thoughts on “Evaluations of Tanker 911, one of the DC-10 very large air tankers”

  1. The airport code under the Shingle fire is probably IWA, which is Phoenix-Mesa Gateway Airport. I’m pretty sure they were flying on that fire from that airport. That’s why they mentioned the long turnarounds. I don’t think there are very many existing bases that can handle that airplane.

    1. Yes they were, there was a huge news story here for a few days about the fire and where the tankers were operating out of. The issue of long turnarounds really doesn’t pan because of the volume of retardant they can carry and deliver in a variety of ways. Even with the turn around issue, they still deliver more on target than any other airtanker currently being used.

  2. Narratives from lead plane pilots/passengers is very informative. It’s very important to know the mission of the drop when evaluating effectiveness.

  3. Dodge
    Are you not the same guy saying we shouldn’t have “large fixed wing aircraft?”
    I think you know not what you talk about!

  4. The DC-10 is the best platform for a VLAT, sure people question the cost, but compare to type 1 helitankers if managed correct the DC-10 can be so much more valuable .

    1. I am a fan of tanked systems. I feel the coverage is better managed than
      pressurized systems (i.e. BAE 146,
      MAAFS and the 747.) Just from observation over the years …

  5. All the LATS and VLATS fill at the same rate (GPM). Flight time to the fire for VLATS is also much faster (depending on the distance) and they do not have to fly back to reload near as often. That equates to reduced overall response time,reduced risk and reduced cost overall. No, that does not mean they are the best and only but the performance and economics are there for those willing to look and all problems have solutions if they are searched.
    For a moment think of retardant as frieght that needs to get somewhere fast. Would UPS or Fedx use a bunch of old pickups and exclude 18 wheelers (or make sure they go out of business)? It really boils down to having all the right tools in the tool box. If USFS fire aviation had real leadership they would ask for the money for the power tools instead of saying “its complicated” or this or that. The tool box should also include P3s that meet the CAP requirements or prove why the CAP should not apply. I do not think it is genuine to simply say that the tool box should have only this plane or that one. Too much is being lost and its not getting any better folks. FYI positive evaluations for both VLATS go back years now. Good to see some of them getting into Wildfire Today. Thanks BIll.

  6. One can see that the plumb of liquid water dropped on fires does not put much water on the fire. The heat and wind spread the liquid water and evaporate a significant amount before it hits the target, if it hits at all. By using solid water-ice cubes or chips, more accuracy in the drop,and more “solid water” dropping threw without evaporating could result in greater fire suppression. The additional cooling effect of ice would take heat away from the fire. A test of this method would not take much effort.

  7. Great to see your planes flying out of the Casper/Natrona County International Airport. I read a story a while back about setting up for the DC10 to fight fires in the area. This seems like the best way to fight the inaccessible, very rugged terrain in the Farris Mountains.

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