Boeing engineers and mechanics are scrambling to meet an already stretched out schedule and get the 767-based platform for the Air Force’s new KC-46 refueling tanker into the air by year end, with an internal flight target of Dec. 27.
That’s six months later than projected at the beginning of this year.
And the cost of the effort is mounting steeply for Boeing, which is responsible for cost overruns in this initial development phase above a contract ceiling of $4.9 billion.
The government’s latest projection for the cost of tanker development has ballooned to $1.5 billion above that contract ceiling, Brig. Gen. Duke Richardson, who heads the Air Force tanker program, said Monday.
The Air Force’s previous estimate had been for a $1 billion overrun.
Richardson said in an interview that the new estimate is based on Boeing’s performance on the work completed thus far, and factors in manufacturing delays due to wiring issues this year as well as potential risks ahead, including possible surprises once flight tests begin.
Spirit AeroSystems in Wichita is building the tanker’s forward fuselage, struts and nacelles. The plane uses the Boeing 767 as its platform.
McConnell Air Force Base in Wichita is scheduled to receive 36 new tankers.
Two Boeing insiders with knowledge of the program said the tanker team in Everett is working feverishly to resolve remaining systems problems and is under orders to prep the first plane “with the minimum capability to make it fly.”
Richardson indicated the Air Force’s priorities are much the same.
“At this point we need Boeing to get Number One in the air,” he said.
The flight from Paine Field, a public airport outside Everett, is the first public milestone for the program, which is set to earn Boeing $51 billion for delivering a total of 179 tankers to the Air Force.
The plane’s take-off will mark the beginning of flight tests that will eventually involve four test aircraft.
The first plane is not outfitted with the military systems that would make it a tanker, such as the air-to-air refueling boom.
It’s just the basic airplane platform: a modified commercial 767 with a 787-style cockpit, a strengthened airframe, four extra fuel tanks in the cargo bay, and the plumbing and wiring to support the tanker mission.
The runup to first flight hasn’t gone smoothly.
After the airframes for all four test aircraft were completed this year, Boeing had to repeatedly remove and reinstall complex wiring systems in the first airplane.
Richardson said the wiring had to be redesigned because the various redundant wire bundles that independently control critical systems were not sufficiently separated.
Once that was corrected, he said, Boeing had to further adjust the design so that the wires would still physically fit into the various bends and crevices in the airframe.
The painstaking unwiring and then rewiring of the first airplane delayed this initial flight by months, and added an extra $425 million in unplanned expenses to the cost overrun that Boeing must swallow.
Because of the delays, Boeing has committed to submit a detailed revised schedule to the Air Force in February.
Even if the cost overrun is as high as the government forecasts, Boeing could potentially make up for the loss in the later stages of the program.
Boeing vice chairman and chief operating officer Dennis Muilenburg said earlier this month that the company anticipates follow-on orders from both the Air Force and from international customers such as South Korea.
He said Boeing expects to build in total “probably closer to 400 to 500 aircraft.”
Among the issues being tackled this week is a problem in starting the engines using the Auxiliary Power Unit in the tail of the airplane, said one insider.
Richardson said that some 23 functional tests that are not safety-of-flight matters will be left undone until after first flight so as not to slow down the process of getting the Federal Aviation Administration (FAA) to certify the plane as airworthy.
“Reducing the risk on the airworthiness certification paperwork is more important than finishing some of the jobs that could have been done,” said Richardson.
Despite the delays to first flight, Boeing continues to insist that it remains on track to fulfill its contract requirement of having 18 operational tankers built and ready to deploy by late 2017.
Richardson declared himself “pretty confident” that the 767-2C will fly by month-end.
The first airplane fully equipped as a KC-46 tanker will be the second airplane to roll off the line, which is scheduled to fly in April.
Richardson said that second plane has more wiring that the base airplane, and the wiring on airplane Number Two is now 78 percent complete.
He said he feels “very good” about the wiring fix on the first plane and that he'll feel “really, really good” once the wiring on the second is completed.
Two of the four test planes will be baseline 767-2Cs that will focus on achieving FAA certification.
The other two will be fully equipped KC-46 tankers and will be used to test the military systems and to certify that the tanker is ready to refuel a variety of receiver airplanes.
The KC-46 design includes an advanced refueling boom that is hooked up to a jet fighter by an operator who sits at a station behind the cockpit.
Using a 3D video-display monitor, the boom operator remotely navigates the telescopic tip of this refueling tube toward the receiving fighter’s fuel receptacle.
Integration of the complex software systems that control this military hardware is a major challenge.
One potential risk ahead, according to Richardson, is the possibility of finding problems in controlling the boom in flight once the KC-46 flight tests start.
Next summer, after the FAA completes initial flight test inspections, Boeing will have to demonstrate the ability to pass fuel in flight to a variety of fighter aircraft.
Only if that’s successful will the Pentagon in September give the go-ahead for Boeing to begin building the first production tankers.
At this stage, any further delays or unexpected problems could push that target date out.
“Most of the margin … is gone” said Richardson.
To keep on track for 18 tankers ready to deploy in 2017, Boeing must hand over the first tanker for the Air Force to test and evaluate in the fall of 2016.
Yet despite the program glitches this year, Muilenburg said Boeing management is “feeling very good about where that program is at now.”
“We’ve got some of those technical issues behind us,” Muilenburg said in New York. “We'll now focus on executing the flight test program under development, and then getting the program into production.”