Boeing KC-46 Pegasus
The Boeing KC-46 Pegasus is an American military aerial refueling and strategic military transport aircraft developed by Boeing from its 767 jet airliner. In February 2011, the tanker was selected by the United States Air Force as the winner in the KC-X tanker competition to replace older Boeing KC-135 Stratotankers. The first aircraft was delivered to the USAF in January 2019.
The USAF intends to procure 179 tankers by 2027. The Air Force indicated that the number of KC-46A aircraft to be procured had increased to 188 which is the absolute maximum number available under the original deal. The Air Force has also elected to pursue a "Tanker Production Extension Program" which will lead to a new contract with Boeing for up to 75 new KC-46A. The total airfare program would grow to 288 KC-46A if all options are exercised.
Development
Background
In 2001, the U.S. Air Force began a procurement program to replace around 100 of its oldest KC-135E Stratotankers, and selected Boeing's KC-767. The Boeing tanker received the KC-767A designation from the United States Department of Defense in 2002 and appeared in the 2004 edition of DoD model designation report. The USAF decided to lease 100 KC-767 tankers from Boeing.U.S. Senator John McCain and others criticized the draft leasing agreement as being wasteful and problematic. In response to protests, the USAF struck a compromise in November 2003, whereby it would purchase 80 KC-767s and lease 20 more. In December 2003, the Pentagon announced a freeze on the program over an investigation into alleged corruption that led to the jailing of one of its former procurement executives who applied to work for Boeing. The KC-767A contract was canceled by the DoD in January 2006.
USAF KC-X program
In 2006, the USAF released a request for proposal for a new tanker program, KC-X, to be selected by 2007. Boeing announced it may enter a higher capability tanker based on the Boeing 777, named the KC-777 Strategic Tanker. Airbus partnered with Northrop Grumman to offer the Airbus A330 MRTT, the tanker version of the A330, which was marketed to the USAF under the designation KC-30. In January 2007, the USAF issued the KC-X Aerial Refueling Aircraft RFP, calling for 179 tankers, four system development and demonstration and 175 production, in a contract worth an estimated US$40 billion. Northrop and EADS expressed dissatisfaction at how the RFP was structured and threatened to withdraw, leaving only Boeing in the running.In February 2007, Boeing announced it was offering the KC-767 Advanced Tanker for the KC-X, stating that the KC-767 was a better fit than the KC-777 for the requirements. In April 2007, Boeing submitted its KC-767 tanker proposal to USAF. The KC-767 offered for this KC-X round was based on the in-development 767-200LRF, rather than the -200ER on which Italian and Japanese KC-767 aircraft are based, differing by combining the -200ER fuselage, -300F wing, gear, cargo door and floor, -400ER digital flightdeck and flaps, uprated engines, and "sixth-generation" fly-by-wire fuel delivery boom.
Boeing submitted its final proposal in January 2008. In February 2008, the DoD chose the KC-30 over the KC-767, the USAF subsequently designated it KC-45A. Boeing submitted a protest to the United States Government Accountability Office in March 2008 and waged a public relations campaign in support of their protest. In June, after USAF admissions on bidding process flaws, the GAO upheld Boeing's protest and recommended the contract be rebid. In July 2008, Defense Secretary Robert Gates announced that the USAF would reopen bidding, and put the contract into an "expedited recompetition" with Defense Undersecretary John Young in charge of the selection process, not the USAF. A draft of the revised RFP was provided to contractors in August 2008 for comments. However, in September 2008, the DoD canceled the KC-X solicitation.
In September 2009, the USAF began a new round of bids with clearer criteria, including reducing the number of requirements from 800 to 373 in an attempt to simplify the process and allow more objective decision making. In March 2010, Boeing announced it would bid the KC-767 for the new KC-X round. EADS stated in April 2010 it would submit a bid without Northrop Grumman as a U.S. partner. Boeing submitted its KC-767 "NewGen Tanker" bid, based on the 767-200 with an improved version of the KC-10's refueling boom, and cockpit displays from the 787, in July 2010. Boeing submitted a revised bid in February 2011.
In addition to the KC-X, observers speculate that a modified KC-46 would be used as the basis of the KC-Y tanker program, the second step of the USAF's three-step tanker renewal plan, as replacing it with something entirely new would likely be too big a risk. In September 2016, Air Mobility Command stated that the follow-on KC-Y acquisition program to replace the remaining KC-135s had been abandoned in favor of further KC-46s with upgrades.
Selection and early development
In February 2011, the USAF announced the selection of Boeing's KC-767 bid, which was designated KC-46A. Boeing was awarded a development contract, which called for the delivery of 18 initial operational KC-46s by 2017. The USAF sought a total of 179 new tankers. In June 2011, development costs were reportedly projected to overrun by about $300 million. Boeing would be responsible for this amount, which exceeds the contract cost cap of $4.9 billion. In July 2011, revised projections indicated a reduced cost overrun. In 2013, the USAF added additional crews and flight hours to their future plans in response to a review that showed that the best of current plans did not take full advantage of the KC-46's cargo and aeromedical evacuation advantages over the KC-135.In August 2013, Boeing and the USAF completed a critical design review for the KC-46. With the CDR complete, the design was set and production and testing could proceed. Wing assembly for the first aircraft began in June 2013. Flight testing of the 767-2C airframe, which would be reconfigured into the KC-46, was scheduled to begin in mid-2014. The first fully equipped KC-46 was projected to fly in early 2015. The contract called for Boeing to build four test aircraft and deliver 18 combat-ready tankers by August 2017. The USAF intended to buy 179 KC-46s, with all delivered by 2028.
In December 2013, Boeing joined the wings and fuselage for the first 767-2C to be adapted into a KC-46A. The first of four 767-2C provision freighters were to complete assembly by the end of January 2014. Once assembled, it would go through ground vibration and instrumentation testing and have body fuel tanks added. The first test flight would occur during summer 2014 and include measuring its rate of climb and descent. The Engineering Manufacturing and Design model was to be integrated with the needed systems and technologies to become a military-standard KC-46A by January 2015. Seven low-rate production KC-46s were to be delivered in 2015, 12 in 2016, and 15 delivered annually from 2017 to 2027. The last of four test aircraft began assembly in January 2014.
In April 2014, the GAO found that the KC-46 program was projected to underrun its projected cost estimate of $51.7 billion by $300 million. The program acquisition unit cost per jet will be $287 million, $1.8 million less than estimated. The GAO noted that delays in training air crew and maintainers could cause testing to slip 6–12 months, but stated that the program had not missed any major milestones and that the development of about 15.8 million lines of software code was progressing as planned. In May 2014, the USAF estimated the development program's cost, including the first four aircraft, could rise from $4.4–4.9 billion to $5.85 billion.
In July 2014, Boeing recorded a $272 million pre-tax charge to cover the tanker's wiring redesign. The wiring issue arose when it was found that 5-10% of the wiring bundles did not have sufficient separation distance or were not properly shielded to meet a USAF requirement for double or triple-redundant wiring for some mission systems. In September 2014, it was confirmed that the wiring redesign would delay the first 767-2C flight from June 2014 to November 2014. In March 2015, the program cost to develop and procure 179 tankers was projected to total US$43.16 billion.
Flight tests and delays
The 767-2C's first flight took place on 28 December 2014. It flew from Paine Field and landed at Boeing Field. In March 2015, a refueling test with a C-17 transport was stopped because of a higher-than-expected boom axial load while delivering fuel. The problem was caused by the turbulent "bow wave effect" generated by two large aircraft flying in line. In January 2016, the KC-46 successfully refueled an F-16 for the first time during a five hour 36 minute sortie. Test refueling of several other military aircraft followed, including a C-17, F/A-18, A-10, and AV-8B. In February 2016, a KC-46 refueled an F/A-18, using its probe-and-drogue system for the first time.In July 2015, Boeing announced a further $835 million pretax charge for the faulty integrated fuel system's redesign and retrofit. Wiring and fuel system flaws could delay contracts worth $3 billion for up to eight months. Following schedule revisions agreed by the USAF and Boeing, the first flight of a fully equipped KC-46 was delayed to as late as September 2015. The Bank of America/Merrill Lynch noted in July 2015 "We fail to understand how Boeing could take a $1.26 billion pre-tax charge on the Boeing KC-46A program since the program is based on the 767 airframe that has been in production for over 30 years."
In March 2016, the Defense Contract Management Agency reportedly had low confidence in the August 2017 deadline, predicting the first 18 tankers' delivery to run about seven months late based on past performance and current risks, such as production delays, a new joint USAF-Boeing schedule review, and flight test uncertainties. The Pentagon's test office was to start combat testing in April 2017. An April 2016 GAO report projected an additional four months beyond the August 2017 target to deliver 18 KC-46s, and that operational testing will not begin until May 2017 and will not be completed until two months after delivery of the first 18 aircraft, risking late discoveries of problems. The GAO noted that Boeing had not obtained Federal Aviation Administration's approval for two key aerial refueling systems—the centerline drogue system and the wing aerial refueling pods, which were built without following FAA processes—Boeing projected readiness for FAA certification by July 2017, over three years late. The 18 KC-46s were to include the four EMD aircraft raised to operational standards, plus the first 14 low-rate production tankers. Instead, 16 of the 18 were off the production line. Boeing was liable for all late design fixes on tankers delivered before testing ended.
In April 2016, the fourth test aircraft, 767-2C EMD-3, first flew. EMD-3 focused on environmental control systems, including temperature and smoke penetration testing. Two days later, Boeing took another pre-tax charge of $243 million for cost overruns, bringing the total amount paid for tanker cost overruns to $1.5 billion. Boeing president and chief executive Dennis Muilenburg stated that 80% of the test points required for a positive Milestone C decision had been completed. Flight testing helped determine whether a refueling fault could be resolved by either software or hardware changes, which Boeing worked on in parallel. In May 2016, a further delay of at least six months due to technical and supply chain issues was reported, potentially requiring program re-structuring and cuts. At the time, only 20% of the flight tests were completed. In June 2016, USAF spokesman Maj. Rob Leese confirmed that, while the contract with Boeing lacked predefined delay penalties, not delivering the 18 certified KC-46s by August 2017 is a contract schedule breach, and that the USAF would receive considerations from Boeing in the schedule re-baseline after the RRA delay. In July 2016, US Defense Acquisitions Chief Frank Kendall confirmed that the tanker program office was studying the delay's cost to the USAF, and that it was entitled to consideration for losses from operating the KC-135 for longer than planned.
On 10 July 2016, Boeing's defense unit CEO, Leanne Caret, reported positive results from early flight tests with a modified boom. On 21 July 2016, Boeing took a further $393 million charge on the program, bringing the total value of penalties to almost $1.9 billion. The charge reflected higher costs associated with the schedule and technical challenges, such as the boom axial load issue, delays in the certification process and concurrency between testing and initial production. The initial 18 KC-46s were equipped with the boom and centerline drogue, but not the wing-mounted wing-aerial refueling pods needed for full contractual Required Assets Available, they were delivered separately later.
On 5 July 2016, USAF spokesman Daryl Mayer stated that, despite the testing delays, Milestone C approval was expected in the following month, and that Boeing would add a fifth EMD aircraft to accelerate testing. EMD-1 and EMD-3 primarily conducted flight tests towards FAA airworthiness certificates, while EMD-2 and EMD-4 focused on USAF aerial refueling and mission system testing. An F-16 was successfully refueled on 8 July, and a C-17 on 12 July 2016. Once the hardware fix is verified, a KC-46 with the updated boom underwent regression testing on the F-16, followed by refueling demonstrations with the C-17 and A-10 for the final test for Milestone C approval. On 15 July 2016, the KC-46 successfully refueled an A-10, offloading 1,500 pounds of fuel at 15,000 feet. At the time, more than 900 flight test hours have been completed by the five EMD aircraft. On 12 August 2016, the program received Milestone C approval, indicating production readiness. The issuing of contracts for two lots covering 19 aircraft was expected within 30 days.
In January 2018, final FAA certification testing was reportedly roughly 94 percent complete. Boeing announced its FAA certification in September 2018, with military certification outstanding. Aircraft refueled during testing include the F-16, F/A-18, AV-8B, C-17, A-10, KC-10, KC-135 and the KC-46 itself. In January 2019, a KC-46 from the 418th Flight Test Squadron at Edwards AFB made connection with an F-35A, the occasion being the first time that the KC-46 connected with a fifth-generation jet fighter. Completion of refueling certification of the F-35 by the KC-46 was announced by the 412th Test Wing in June 2019.
In March 2020, the USAF announced that chronic leaks in the fuel system had been upgraded to a Category I deficiency. The USAF identified the issue in June 2019, but had not originally believed it to be serious. Crews became aware of the issue when they discovered fuel between the primary and secondary fuel protection barriers. There was no known root cause at the time of the announcement. By January 2021, Boeing's losses on the program were estimated at $5 billion. At the time, it was expected that the KC-46 would not be combat ready until at least late 2023.