Boeing's KC-46A Pegasus
In Picture: Boeing's KC-46 aerial refuelling tanker conducts receiver compatibility tests with a U.S. Air Force C-17 Globemaster from Joint Base Lewis-McChord, 12 July 2016.Wiki Commons / Christopher Okula / US Air Force

Boeing has received another contract for 15 additional KC-46A aerial tankers from the US Air Force. The company received the contract on January 27, Defense News reported.

Read: Will Indian Air Force opt for Boeing KC-46 Pegasus for its six tanker requirements?

"This award is great news for the joint Boeing-Air Force team and reinforces the need for this highly efficient and capable tanker aircraft. Our Boeing industry team is hard at work building and testing KC-46 aircraft, and we look forward to the first delivery," said Mike Gibbons, Boeing KC-46A tanker vice-president and program manager.

The current order is a modified version of an older contract, which adds spare engines, and five wing-refuelling-pod kits along with 15 KC-46 aircraft.

The addition of 15 KC-46A takes the total to 34 tankers that Boeing is producing. The US Air Force could eventually buy 179 aircraft.

The first deliveries will start later this year and the company hopes that it delivers the first 18 by January 2018.

The report also noted that the program has been through several delays and technical problems. US contracts like these work under fixed price and the company has to pay from its pockets any excess expenses.

This has left the company responsible for over $2 billion in charges, which includes the additional $201 million post-tax penalty that it disclosed during a 2016 fourth quarter earnings call.

Boeing has built two KC-46A tankers and four test aircraft (two commercial 767-2C configured planes). These aircraft have so far flown about 1,500 hours, the report noted.

The KC-46 Pegasus could jump into the Indian Air Force requirement of six multi-role tanker transport (MRTT) aircraft; previous two tenders on this were withdrawn due to conflict between "procurement cost" and "life cycle cost," Business Standard reported in November, 2016.