What is the heart of U.S. airpower? It’s not the fleet of unmatched fighters, including the fifth-generation F-22s and F-35s. It’s not the bomber force, unequalled in the world. Nor is it the family of unmanned aerial systems, the Predator, Reaper or Global Hawk. It is the aerial refueling tanker. Without the massive fleet of 415 KC-135 and 58 KC-10 tankers, the U.S. Air Force would be tethered to its airfields, unable to project power globally. In fact, without the tanker fleet, the Army’s ability to deploy intercontinentally aboard C-17 transports with assured resupply would be severely curtailed. The Navy too would suffer a degradation in its power projection capabilities since the aircraft carrier wing lacks a serious refueling capability.
New generations of fighters, bombers and even transport aircraft have come and gone while the tanker fleet plodded on. The KC-135 was originally built in 1956 and the last one came off the production line in the mid-1960s. This means that even the newest KC-135 is sixty years old. The KC-10, a spring chicken by comparison, came into service in 1981. Although it is decades newer than the KC-135, it is being operated at twice the rate, rapidly shortening its lifespan.
Both are militarized variants of commercial aircraft; the KC-135 was designed around the venerable Boeing 707 and the KC-10 was based on the DC-10. Both use commercial engines, the CFM 56 on the KC-135 and the CF 6 on the KC-10. The use of commercial airframes and engines helped to reduce production prices and decreased logistics and maintenance costs.
Even though, in theory, there is plenty of life left in both the KC-135 and KC-10, both are aging aircraft. Maintenance and support costs, particularly for the KC-135, are rising at an alarming rate. There is always the possibility of an unanticipated catastrophic problem that would require grounding the entire KC-135 fleet. It became imperative to begin a replacement program in anticipation of the time when it would no longer be economical or even safe to fly the venerable KC-135.
The KC-46 is an example of smart acquisition. It is much more than just a version of the proven commercial Boeing 767 airframe. It incorporates cockpit advances now on the 787 as well as an advanced version of the proven KC-10 fuel boom. The KC-46 will be powered by versions of the Pratt & Whitney 4062, one of the most successful and reliable engines now in commercial service. These engines are so reliable that some observers expect them not to need depot maintenance for 25 years. This will translate into huge maintenance savings and greater availability.
The KC-46 program is on track and is a good working partnership between government and industry. It is a great example of applying the best of commercial aerospace technology to meet a military demand. The first flight of a test version of the production aircraft is scheduled for this summer. The first fully-equipped aircraft is scheduled to roll out of the production facility by the middle of 2015. Boeing is on contract to deliver 18 combat-ready tankers by August 2017. The Air Force plans to buy 179 KC-46s between 2017 and 2028.
The Air Force has made it clear that the KC-46 is one of its three priority modernization programs. Some senior service representatives even call it the number one priority. This actually makes sense. No tankers, no global U.S. military.
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