KC-135 Statofortress tanker planes have been refuelling fighter craft in-flight for more than 60 years. While such longevity is commendable, the US military’s fleet of mid-air refuellers is in desperate need of an update. And that’s where this new flying petrol station comes in.
The Boeing KC-46A is a derivative of the Boeing 767-200 built at Boeing’s Everett, WA facility and converted to military use at another Boeing facility in Puget Sound. The KC-46 program has been a long time coming. Congress and the military have wrangled over funding for the project for more than a decade, finally agreeing to an initial investment of $US3.5 billion in 2011 for Boeing’s design. The aerospace company has until 2017 to deliver the first 18 tankers with the remaining 161 due in 2028. In all, explains Maj Gen John Thompson, program executive officer and program director for the KC-46, the deal is "worth about $US32 billion in then-year dollars, goes from about two years ago out into the 2020s and is something that they will be able to leverage into a very important weapon system for the United States Air Force for decades to come. Absolutely, it is a win-win."
The KC-46A will offer greatly-improved performance and capabilities than it sexagenarian predecessor. The new plane measures 50m in length with a 48m wingspan. It’s powered by a pair of Pratt & Whitney PW4062 turbofan engines, each providing 28,700 kg/f of thrust to get the plane -- and the 96,000kg of fuel it carries -- off the ground and keep it aloft for a range of more than 6000 nautical miles.
The plane’s crew of three (two pilots and a boom operator) operate within a large glass cockpit augmented with banks of monitors providing critical mission information. The pilots use a bank of 15-inch displays to check flight and weather data while the refuelling operator will be afforded a set of 24-inch 3D displays giving him a panoramic 185-degree field of view.
Designed to support and refuel any fixed-wing receiver capable aircraft for the US Air Force, Navy and Marines, the plane is typically equipped with either a 4500-litres-per-minute centreline boom or 1500-litres-per-minute centreline drogue system. It can also carry a pair of 1500-litres-per-minute Wing Air Refuelling Pods to pull crazy stunts like this. What’s more, the KC-46A can itself receive in-flight refuelling, allowing it to remain aloft practically indefinitely.
In addition to fuel, the KC-46A can carry up to 114 people, 18 standard military cargo pallets, or 58 patients (24 litters, 34 ambulatory). Across the board -- fuel, passengers and cargo -- the KC-46A carries more than the plane it will eventually recapitalise.