Montana Water Bombers

[CAPFlyer]

The numbers don't look right for 3 huge jet engines at a 38K burn in 2 hours.
So what is take off power approximate? And what is 10k hp in turbine terms? That's what I'm guessing engine out put is at
that fuel consumption.

Sorry if you don't like the numbers, but the chart was a copy of the AOM as given to Continental Airlines DC-10 crews. This also assumes a landing weight of 320,000 pounds. So let's work out a few items.

The "empty weight" of a DC-10-30 in passenger config is ~267,000 pounds, so it assumes you're flying with a fixed payload of 53,000lbs (passengers and fuel reserves). Now, considering that this includes a full passenger cabin as well, the DC-10 Tankers, while DC-10-30 models, have their interiors and cargo handling equipment removed, so the dead weight of the tank and associated modifications should be a wash if not a net loss in weight. The standard domestic fuel reserves are usually around 20,000 pounds (so takeoff fuel would be a minimum of 60,000 pounds of fuel), meaning that they can carry 33,000 pounds of whatever they want and still meet that number since the plane is landing without retardant onboard. Even though the "live load" of Phos-Chek is ~105,000 lbs, that weight only applies to the first half of the flight. With a jet, this is meaningless to fuel consumption for the most part since any penalty to fuel consumption on the "out" leg of the sortie is at minimum counteracted by the "in" leg which can also be flown at a higher altitude and thus lower fuel consumption.

Aviation turbofan and turbojet engines are not rated by horsepower, only thrust. The CF6-50C is rated at ~50,000 pounds of thrust depending on the exact configuration. Power setting on takeoff varies significantly depending on temperature and pressure altitude, but at sea level on a standard day, power is set at 111.7% N1 for takeoff and then is reduced to 99.1% for the start of climb before rising back to ~102.6% N1 at the top of climb (12,500 feet per Larry and the 10 Tanker website). Beyond that, I don't have the charts, but again, 38,000 pounds is about right for the burn-off on a 2-hour mission. It sounds low because high bypass turbofan engines are extraordinarily efficient when pulled back for cruise.

Oh, and by comparison, 38,000 pounds of fuel is more than what a 737-300 (like the ones that Coulson bought) can hold IN TOTAL (35,600lbs) and it has 2 engines that together almost equal the power of 1x DC-10 engine. So, again, you think it sounds "small", but it's not.

[CoastieJohn]

This is the above 2014 USFS paper (first page) on their DC-10.

US Forest Service Fire & Aviation Management DC-10 Briefing Paper
Updated May 1, 2014

Topic: Follow up - DC-10 Very Large Airtanker (VLAT) Operational Considerations

Issue: The DC-10 has unique operational considerations including low level supervision, terrain, facilities, and cost.

Background: 10 Tanker Air Carrier was awarded a line item for a DC-10 on the Next Generation Large Airtanker Exclusive Use contract and a line item on the Very Large Airtanker (VLAT) Call When Needed contract. These aircraft remain a VLAT in category and require special considerations for use.

Key Points:  Low Level Supervision: Aerial supervision is required for this aircraft while dispensing. • The 10 Tanker flight crews will not be issued an initial attack (IA) approval card, so a Leadplane or Aerial Supervision Module must be on scene to direct the resource to the intended dispensing locations. • The cruising speed of the DC-10 is around 370 knots (TAS) which is greater than Large Airtankers (LATs) and leadplanes. Users/ dispatchers need to insure that a LP/ASM will arrive in time to provide aerial supervision. • Trainee Leadplane Pilots (LP) under the supervision of an onboard Leadplane Pilot Instructors (LPI) may conduct VLAT operations. All LPIs are now qualified for VLAT operations and will supervise the trainee during these missions.

 Terrain: VLATs are less maneuverable than LATs and should be used in less challenging terrain that affords better maneuverability for dispensing. • The DC-10 is relatively agile for its size; however the momentum is greater and requires planning by the supervising aircraft to provide a stabilized path for delivery. • The VLATs minimum drop height is 200 feet above the top of the vegetation with a target height of 250 feet.
 Facilities: The DC-10 weighs between 340,000 and 400,000 lbs. in contract configuration. It has a Dual Tandem wheel configuration. • Tanker Base and parking ramps must have a weight bearing capacity sufficient to support the DC-10. Local bases need to insure both the airport and agency engineering have information indicating ramp capacity. Letters documentation and drawings of the ramp structure must be on file at the airtanker base. • Congestion at a base may preclude operations due to conflicts with other aircraft types. • Air stairs are needed for the crew to enter/exit the aircraft. 10 Tanker is responsible for the payment of the stairs and airtanker personnel are not to operate the equipment. • Loading the aircraft will take anywhere from 12-15 minutes with a three pump/hose configuration or 25 minutes with a one pump/hose setup. • Simultaneous Loading and Fueling and/or Hot Retardant Loading (HRL) is acceptable only after approval of the corresponding Regional Aviation Officer and the local line officer and being added to the base operations plan. The local airtanker base manager (ATBM) is delegated the decision authority once this is in the base plan. • Facilities that accept the DC-10 will need to provide offload capacity of at least 10,000 gallons.
 Cost: The FS funds the availability of $27,285 per day. The rate is on par with Next Gen LATs awarded under this contract. • The dry flight rate is $12,750/hour when the aircraft is fully loaded with retardant to 11,600 gallons. When the aircraft is carrying 5500 gallons or less the rate drops to $4598/hour. After 150 hours of use, a further price adjustment occurs. • The DC-10 has an hourly fuel consumption of 2275 gallons when carrying 5500 gallons or less and 2550 gallons per hour when fully loaded. The Forest Service utilizes the Aviation Into-plane Reimbursement (AIR) cards sponsored by the Defense Logistics Agency (DLA) for purchasing fuel. This provides the government a cost savings of about $1.50 per gallon from the retail rate.

 Contact: Scott Fisher, WO-FAM National Airtanker Program Manager (208) 387-5968 sfisher01@fs.fed.us