Boeing missed its own goal for delivery of the first
operational KC-46 tanker, and the firm is now obligated to hand
18 of them over to the Air Force by October.
But several important flaws remain in the aircraft, and
the firm and the government are working to resolve
The KC-46’s years-long development has been stymied by
The first operational KC-46A Pegasus — the tanker being designed
by Boeing to replace the aging KC-135 — took its maiden flight on
That flight came after numerous delays and cost overruns that have stymied the tanker’s
development over the past several years. Even though it got
off the ground in December, Boeing admitted at the time that it
would miss a self-imposed deadline to give the Air Force the
first operational KC-46 by the end of 2017.
Now the Air Force expects to receive the first
operational KC-46 by spring 2018, and Boeing is obligated to
deliver 18 of the new tankers by October. But major defects
remain unresolved, according to Aviation Week.
The most worrying deficiency is the tendency of the tanker’s boom
— where the fuel flows — to scrape the surface of the
aircraft receiving fuel.
The problem could endanger the aircrews involved and risks
compromising the low-observable coating on stealth aircraft like
the F-22 and F-35 fighters. A KC-46 with a refueling boom
contaminated by stealth coating may also have to be grounded.
Representatives from the Air Force and from Boeing told Aviation Week that they
are working on the problem, with personnel from the government
and industry reviewing flight data to assess such incidents and
compare them to international norms.
Their assessments will help decide whether changes are to
be made to the camera used for refueling on the KC-46. The
Pegasus’ boom operator sits at the front of the aircraft while
directing the boom, relying heavily on the camera. Older tankers
have the boom operator stationed at the back of the plane to
guide the boom in person. A decision on the camera is expected by
A Boeing spokesman said similar contact between the boom and the
receiving aircraft happens with the Air Force’s current tankers
A Boeing spokesman also told Aviation Week in December that an
issue with the KC-46’s high-frequency radio had been resolved,
but an Air Force spokeswoman said the force was still working on
it, expecting to have options to address it by January.
The radios use the aircraft’s frame as an antenna, which
sometimes creates electrical sparks. The Air Force wants to
ensure they can never broadcast during refueling in order to
Issues with uncommanded boom extensions when the refueling boom
disconnects from the receiving aircraft with fuel flowing have
been reduced to a Category Two deficiency, an Air Force
spokeswoman told Aviation Week. The
solution to that problem is expected to be implemented in May,
the spokeswoman said.
The Air Force still expects the first operational KC-46s by late
spring, arriving at Altus Air Force Base in Oklahoma and
McConnell Air Force Base in Kansas.
Air Force Gen. Carlton Everhart, chief of Air Mobility Command,
told Air Force Times that once
testing is finished and the new tankers start to be delivered, he
expects “they’re going to clear out pretty quick” to Air
Boeing won the contract to develop the new tanker in 2011, and
the Air Force expects to buy 179 KC-46s
under the $44.5 billion program. Under the contract, Boeing is
responsible for costs beyond the Air Force’s $4.82 billion
commitment. As of late 2017, the defense contractor had eaten
about $2.9 billion in pretax costs.
Despite his limited involvement in the Pentagon’s weapons
programs, Defense Secretary Jim Mattis issued a stark warning to
acquisition officials in November, telling them he was “unwilling
(totally)” to accept flawed KC-46 tankers.