Tanker aircraft and their crews help put the “superior” in U.S. air superiority.
Tankers enable fighter and bomber aircraft to reach targets further into enemy territory, airlift aircraft to haul equipment across the globe and surveillance aircraft to loiter for extended periods over critical airspace. Tankers are also capable of transporting cargo, people and equipment to bases almost anywhere in the world.
Each time a C-17 delivers critical supplies or food, a B-2 bomber targets an insurgent safe house, or an F/A-18 sets out on a mission to provide aerial support, the tankers are there behind the scenes, flying multiple sorties to get those planes the fuel that they need to complete their missions.
Yet many people still don’t truly understand what a tanker is, and how it does its job. Aerial refueling can be described as an aerial ballet conducted at 30,000 feet where thousands of pounds of fuel pass between two aircraft traveling at more than 450 mph. Tanker missions require detailed planning and constant training to ensure things go off without a hitch. Most tankers are based on the airframes of commercial jetliners, modified to carry hundreds of thousands of pounds of fuel in addition to pallets of cargo.
Experienced tanker crews make it look easy, but fighter, bomber and airlift pilots will tell you that there’s no room for mistakes.
When the receiver aircraft enters the preplanned air refueling track, the tanker aircraft turns to fly directly toward the incoming plane at closure rates approaching 900 knots. At a predetermined point the tanker executes a 180-degree turn to roll out in a position one mile ahead of and 1,000 feet above the receiver aircraft. Then the thirsty aircraft gets the signal to climb into position a mere 20 feet behind the tanker aircraft, traveling between 190 and 320 knots indicated airspeed (KIAS).
There are two basic refueling methods: (1) a telescoping “flying boom” attached to the rear of the aircraft, or (2) a flexible “hose and drogue” system mounted either to fuel pods on the wings or at the rear of the aircraft.
Invented by Boeing in 1948, the flying boom system enables a tanker to transfer over 900 gallons of gas per minute to an aircraft, a rate which could fill a typical automobile gas tank in just over one second. This rate is essential when refueling bombers or long-haul airlift jets. Why is it called the flying boom? Because the boom operator controls two small wings on the boom that literally fly it to the fuel receptacle on the receiver aircraft. Boeing’s KC-7A7 tankers are the only aircraft to use fifth-generation boom technology.
On the other hand, the hose and drogue system simply extends or trails a 70-90 foot hose with an aerodynamic basket behind the aircraft, positioning it directly in front of the receiver aircraft. The hose and drogue method delivers the fuel at a much slower rate, between 400 and 600 gallons a minute, and is typically used to refuel Navy and Marine Corps fighter aircraft.
While the fuel is passing between the two aircraft, they fly on a fixed path with the tanker responsible for the safe navigation of both aircraft. After refueling, the aircraft separate and continue their missions.
Boeing is confident that the KC-7A7 is the best option for the new United States Tanker.
Comments
When you get past the politics, the taxpayer wants their money to go towards a combat system that is reliable and right for the task at hand. No one has done it better over the years than Boeing. As a former tanker planner and chief of tanker operations with several years of boots-on-the-ramp experience, combat, peacetime and special operations global employment, I can tell you unequivocally which of the competing platforms will deliver and the one I want to take to combat.
I assure you, the only proven manufacturer that comes close to meeting all the needs with an off-the-shelf aircraft, is Boeing. Whether it be footprint, ramp load-bearing compatibility, MOG, booms in the air, or cargo, Boeing produces the only viable system. Though I would rather see the engineers design a new platform to replace the 135, this is cost prohibitive, and the 767 comes as close as we can get to a real multi-role tanker replacement for the KC-135. One competitor will say they can put more fuel in the air, but I will argue, operating off a given ramp, I can beddown nearly twice as many of the Boeing aircraft. On a one-to-one basis, the competition may look OK, but when it comes to combat ops, it's never one-to-one. I would challenge any seasoned commander, or air refueling planner, he/she would rather take 10 tankers to combat, vice 5. Numbers give flexibility, cover more airspace, service multiple A/R tracks, creating less of a bottle neck, and inherently take more fuel to the air in a multi-capable platform.
In a multi-purpose platform, true cargo capability is vital. "True" is the operative word here. Hauling 32 763L transload pallets is impressive, but is that more volume and less weight? Boeing has a true cargo floor that can withstand heavy weights, maximizing the 19 763L pallets, which is still one more pallet than our premiere airlifter, the C-17. When Air refueling is the primary mission, why do we need 32 pallets? But then I digress but you get my point. Cargo is important, Air EVAC is critical, and it's imperative to have this secondary capability.
Several arguments can and will be made, but this seasoned combat veteran knows what weapon he wants to take to combat, and Boeing happens to make it! I trust that now that the Air Force has the stick on the decision, skilled and experienced, combat tested veterans in air refueling, will quickly come to the same boots-on-the-ramp perspective and conclusion, and choose the right tool for current and future combat operations. The Boeing 7A7 family!
I'll agree and disagree with this argument every chance I get. Yes, we need a new tanker. NO, it does not need to haul pallets or passengers. Yes, it is "cheaper" to modify a passenger plane rather than build a purpose-built plane from scratch. NO, going cheaper will not get the mission done.
History: I look at the F-15 replacement (F-22) as not being an off the shelf model but a completely new airframe. I look at the C-141 replacement (C-17) as she is also a brand new airframe design. WHY is it we can't do the same for a purpose-built tanker? What is the mission? Cargo? Passenger hauling? No, the mission of a tanker is force extension and force multiplication through air refueling. If it were possible, I'd also have a system where I could refuel and rearm my attack aircraft in the air too.
Mission Requirements: An air refueling platform needs to be able to operate worldwide under less than ideal conditions and provide support to a variety of receiver aircraft. Basically, she needs to be able to take off from a runway that is 150 feet wide and 8,000 feet long while at 75% of her maximum gross weight. Air to air refueling with another tanker can top her off after departure if needed. Gone are the days that we had to run from the alert facility, start 4 engines at one time, taxi and take off within 10 minutes using a SAC 13,500' runway (including the overrun). Ground support requirements also need to be commonly found worldwide. That means we can't plan on having KC-10 specific maintenance stands to inspect the tail engine. That means that we don't need a passenger ramp for the crew to enter or exit the aircraft. That means that we can refuel and start without any ground support equipment. That means that we can work in a heated / air conditioned environment while in Riyadh or in Fairbanks. This also means we don’t waste valuable space in cargo aircraft ferrying support equipment for tankers. Finally, the aircraft will be equipped with boom refueling (proven a life giver to damaged aircraft for years) and drogue refueling (for Navy, Marine, and NATO support).
Crew: With technology, we can go with a crew of three; Pilot, Co-Pilot, Boom Operator. Call me old fashion but the boom pod needs to be in the back and a minimum of electronic systems are needed to control the boom. What we can’t afford is an electronic breakdown when that fighter needs fuel over the Pacific or after battle damage while we drag her back to a recovery location. The aft location also allows the boom to scan the sky for friendlies AND unfriendlies. Finally, we need to plan for augmented crew for extended missions so the crew compartment needs to have a proper water closet (a real airline toilet for those KC-135 crews), hot and cold water in the sink, galley with cooled fresh water capacity, comfortable crew seats, and sleep area with bunks, black out curtains, lee cloth (something to keep you from falling out), and reading lights. Finally, a storage area for crew baggage is a requirement for deployments. That means that we have a large area of “cargo room” that should be filled with fuel bladders / tanks.
Understanding that there is a cost associated with new airframes, the KC-135 was built back in 1950ish and is still active 60 years later. The B-36 Peacekeeper was only in service for 14 years before obsolence and airframe fatigue ended its career. So the tanker we’re building now should be in service until the year 2100. I think that is worth the dollars.
And although this is outside of Boeings control, how about a Tanker Air Command for our new tankers. AMC is not a source of knowledge on how to properly use a tanker asset...they deal with cargo and passengers. Thank you.
(my background: Retired after 20 years KC-135(A, E, Q, R, T) Instructor Boom Operator, last 5 as a TALCE MST. Pulled the last full SIOP alert tour in SAC)