With the schedule for renewal of its aerial refuelling fleet spreading over five decades, the US Air Force is planning three separate tanker replacement programmes. After the initial 179 aircraft to be purchased under the KC-X programme, the USAF plans a KC-Y acquisition beginning in 2024 and followed in 2036 by a KC-Z procurement.
The contest to provide four test and 175 production KC-X tankers to begin replacing the USAF's 520-plus Boeing KC-135 Stratotankers will be launched with release of the final request for proposals on 15 December, leading to contract award next August. The USAF plans a "winner takes all" competition to produce 15 aircraft a year.
Under the plan detailed at the KC-X industry day in late October, the Y and Z tankers could be spiral developments of the winning aircraft, or new designs. "They talked about recapitalising the entire tanker fleet in three tranches, and assuming those would be three different competitions," says Mark McGraw, Boeing vice-president, tanker programmes.
"I think they will eventually recapitalise the -135 between the KC-X itself, or KC-X plus KC-Y, and then KC-Z would be the final piece of the puzzle, the eventual recapitalisation of the [McDonnell Douglas] KC-10," says McGraw. The plan calls for procurement of 15 KC-Ys a year from 2024-36, then nine KC-Zs a year until 2048.
Boeing has yet to decide whether to offer the KC-767 or a 777 derivative against the Northrop Grumman/EADS North America KC-330 a modified Airbus A330. "We have always felt that if the air force wanted to buy a large tanker, which would probably be most in line with replacing the KC-10s downstream, the KC-777 would be a good solution," says McGraw.
The notional recapitalisation plan addresses concerns about continuing manufacture of a modified widebody airliner beyond its likely commercial production life, with KC-X deliveries to be spread over 12 years from early next decade.
"You only get to a KC-Y programme if the air force in its recapitalisation of the -135 wants to take a fresh look at a new platform," says McGraw.
It is harder to predict which Airbus and Boeing commercial platforms will be available to meet the longer-term KC-Z requirement, but McGraw says: "We could launch a KC-777 at any time as long as the 777 platform is still viable in the commercial world."
The air force's oldest KC-135Es will be replaced through its KC-X contest