Aug. 5 (UPI) -- Boeing Co. received a $55.5 million contract modification for engineering work on the KC-46 Pegasus tanker plane, the Defense Department announced.
The new contract modification, announced Friday by the Pentagon, calls for engineering, manufacturing and development of system-level hardware and software for the redesign of the plane's boom telescope actuator.
The boom, which swings out from beneath the plane to refuel other planes, and its three refueling systems have been a source of trouble for the plane's development.
Boeing is three years behind schedule on the program and will not deliver the first 18 aircraft, with all three refueling subsystems -- used primarily to refuel fighter planes in midair -- until June 2020. The aircraft, a variant of the Boeing 767 passenger plane, has been in development since 2011.
In June, the Air Force announced that because of ongoing problems with the KC-46 Pegasus, it would reallocate $57 million from the plane's program to the older refueling tanker, the KC-135 Stratotanker.
The report added that some Air Force commanders don't want their aircraft refueled by the KC-46. In turn, their reluctance in using the plane is further delaying its scheduled use.
Boeing grounded the tankers for one week in March after the Air Force said it found loose tools and other foreign object debris inside the completed airplanes. The issues came just weeks after the company delivered the first two aircraft to the Air Force, and Boeing called the problem "a big deal" in an internal memo in February.
"The tanker's been frustrating," Acting Secretary of the Air Force Matthew Donovan said while visiting Joint Base San Antonio-Lackland.
He noted that the original delivery date for the first 18 planes was August 2017, "and so now here we are almost two years later and not close to those deliveries. So it has been problematic that even though the vendor themselves have taken charge-backs of around $3 billion that they've had to absorb in cost,we still didn't get the aircraft on time."
The Air Force intends to purchase 179 KC-46 planes by 2027. The South Korean military currently has four, and six other countries are considering their purchase.
Work on the contract announced Friday will be performed at Boeing's Seattle facilities, with a completion date of February 2021.