163-696: 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 (USAF) 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. In 2001,
326-399: A V-tail configuration, are used to move the boom by creating aerodynamic forces. They are actuated hydraulically and controlled by the boom operator using a control stick. The boom operator also telescopes the boom to make the connection with the receiver's receptacle. To complete an aerial refueling, the tanker and receiver aircraft rendezvous, flying in formation. The receiver moves to
489-520: A carrier air wing ) to extend the range of its strike aircraft. In other cases, using the buddy store method allows a carrier -based aircraft to take-off with a heavier than usual load less fuel than might be necessary for its tasking. The aircraft would then topped-up with fuel from an HDU-equipped "buddy" tanker, a method previously used by the Royal Navy in operating its Supermarine Scimitar , de Havilland Sea Vixen , and Blackburn Buccaneers ; in
652-736: A critical design review (CDR) 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
815-455: A Hose Drum Unit (HDU). When not in use, the hose/drogue is reeled completely into the HDU. The receiver has a probe , which is a rigid, protruding or pivoted retractable arm placed on the aircraft's nose or fuselage to make the connection. Most modern versions of the probe are usually designed to be retractable, and are retracted when not in use, particularly on high-speed aircraft. At the end of
978-587: A Return-To-Launch-Site abort capability if necessary. At its most efficient altitude and speed, the Blackbird was capable of flying for many hours without refueling. The SR-71 used a special fuel, JP-7 , with a very high flash point to withstand the extreme skin temperatures generated during Mach 3+ cruise flight. While JP-7 could be used by other aircraft, its burn characteristics posed problems in certain situations (such as high-altitude, emergency engine starts) that made it less than optimal for aircraft other than
1141-540: A boom system followed quickly in the autumn of 1948. The first use of aerial refueling in combat took place during the Korean War, involving F-84 fighter-bombers flying missions from Japanese airfields, due to Chinese-North Korean forces overrunning many of the bases for jet aircraft in South Korea, refueling from converted B-29s using the drogue-and-probe in-flight refueling system with the probe located in one of
1304-580: A feat made possible by four aerial refuelings from four pairs of KB-29M tankers of the 43d ARS. Before the mission, crews of the 43rd had experienced only a single operational air refueling contact. The flight started and ended at Carswell Air Force Base in Fort Worth, Texas with the refuelings accomplished over the Azores , Saudi Arabia , the Pacific Ocean near Guam , and between Hawaii and
1467-457: A fixed partition wall between the cargo and passenger, the cost could be limited at $ 96 million. To make up for the cost increase McDonnell Douglas hired Dutch companies to do part of the work. The conversion of the aircraft was performed by KLM and was done from October 1994 to September 1995 for the first aircraft and from February to December 1995 for the second. This was much longer than planned, mostly because McDonnell Douglas delivered
1630-403: A flexible hose that trails from the tanker aircraft. The drogue (or para-drogue ), sometimes called a basket , is a fitting resembling a shuttlecock , attached at its narrow end (like the "cork" nose of a shuttlecock) with a valve to a flexible hose. The drogue stabilizes the hose in flight and provides a funnel to aid insertion of the receiver aircraft probe into the hose. The hose connects to
1793-404: A four-aircraft strike package. USAF KC-135 and French Air Force KC-135FR refueling-boom equipped tankers can be field-converted to a probe-and-drogue system using a special adapter unit. In this configuration, the tanker retains its articulated boom, but has a hose/drogue at the end of it instead of the usual nozzle. The tanker boom operator holds the boom still while the receiver aircraft flies
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#17327725549841956-785: A fraction of their maximum payload on direct flights from the continental United States to Israel . To address this shortfall in mobility, in 1975, under the Advanced Tanker Cargo Aircraft Program , four aircraft were evaluated—the Lockheed C-5 , the Boeing 747 , the McDonnell Douglas DC-10, and the Lockheed L-1011 . The only serious contenders were Boeing and McDonnell Douglas . In December 1977, McDonnell Douglas's DC-10
2119-537: A further four KC-46s. In November 2022, it was reported that Italy was negotiating the purchase of six KC-46s, to be designated KC-767B locally, after deciding to forgo modernization work on the current fleet of four KC-767As. The purchase could have include logistics support for the KC-46A fleet for a period of five years. The total cost of the contract would have been approximately €1.12 billion. Italy's four KC-767As would be sold to Boeing. In July 2024, Italy "halted"
2282-493: A hose-and-drogue system, dubbed UPAZ, and thus later Russian aircraft may be equipped with probe and drogue. The Chinese PLAF has a fleet of Xian H-6 bombers modified for aerial refueling, and plans to add Russian Ilyushin Il-78 aerial refueling tankers. Tankers can be equipped with multipoint hose-and-drogue systems, allowing them to refuel two (or more) aircraft simultaneously, reducing time spent refueling by as much as 75% for
2445-586: A key role in the mobilization of US military assets, taking part in overseas operations far from home. These aircraft performed airlift and aerial refueling during the 1986 bombing of Libya (Operation Eldorado Canyon), the 1990–91 Gulf War with Iraq (Operations Desert Shield and Desert Storm), the NATO bombing of Yugoslavia (Operation Allied Force), War in Afghanistan ( Operation Enduring Freedom ), and Iraq War (Operations Iraqi Freedom and New Dawn). During
2608-564: A large cargo aircraft with a range of at least 4,500 km and the capability to refuel F-16s. In 1992, two DC-10-30CFs were acquired from Martinair in a buy/ leaseback contract. When one of the two aircraft was lost in the Martinair Flight 495 crash, a third aircraft was bought from Martinair. The conversion was handled via the United States foreign military sales program, which contracted McDonnell Douglas. Costs for
2771-693: A maximum fuel offload rate of 470 gallons (1,786 liters) per minute. Unlike the KC-135, the KC-10's hose-and-drogue system allows refueling of Navy , Marine Corps , and most allied aircraft, all in one mission. The final twenty KC-10s produced included wing-mounted pods for added refueling locations. The KC-10 can carry a complement of 75 personnel with 146,000 lb (66,225 kg) of cargo, or 170,000 lb (77,110 kg) in an all-cargo configuration. With that, it can transport those weights for an unrefueled range of 4,400 miles (7,040 km). The KC-10 has
2934-463: A modified KC-46 will 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 is likely 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. In February 2011,
3097-416: A much smaller position-keeping tolerance, staying properly connected to a KC-135 adapter unit is considerably more difficult than staying in a traditional hose/drogue configuration. When fueling is complete, the receiver carefully backs off until the probe refueling valve disconnects from the valve in the basket. Off center disengagements, like engagements, can cause the drogue to "prang" the probe and/or strike
3260-444: A new jet endurance record. FRL still exists as part of Cobham plc . Modern specialized tanker aircraft have equipment specially designed for the task of offloading fuel to the receiver aircraft, based on drogue and probe, even at the higher speeds modern jet aircraft typically need to remain airborne. In January 1948, General Carl Spaatz, then the first Chief of Staff of the new United States Air Force , made aerial refueling
3423-700: 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
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#17327725549843586-484: A pioneer of long-distance aviation. During the 1920s, he made long-distance flights to places as far afield as Africa and Australia and he began experimenting with the possibilities of in-flight refueling to extend the range of flight. Cobham was one of the founding directors of Airspeed Limited , an aircraft manufacturing company that went on to produce a specially-adapted Airspeed Courier that Cobham used for his early experiments with in-flight refueling. This craft
3749-407: A position behind the tanker, within safe limits of travel for the boom, aided by director lights or directions radioed by the boom operator. Once in position, the operator extends the boom to make contact with the receiver aircraft. Once in contact, fuel is pumped through the boom into the receiver aircraft. While in contact, the receiver pilot must continue to fly within the "air refueling envelope",
3912-491: 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
4075-464: 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
4238-577: A side cargo door for loading and unloading cargo. Handling equipment is required to raise and lower loads to the cargo opening. It can carry cargo and serve as a tanker on overseas missions. A need for new transport aircraft for the Royal Netherlands Air Force ( Koninklijke Luchtmacht ) was first identified in 1984. The 1991 Gulf War highlighted the deficiencies in mobility of European forces. In 1991 four categories of transport requirements were established. Category A required
4401-584: A similar dropped line from the receiver, allowing the refueling to commence. In 1935, Cobham sold off the airline Cobham Air Routes Ltd to Olley Air Service and turned to the development of inflight refueling, founding the company Flight Refuelling Ltd . Atcherly's system was bought up by Cobham's company, and with some refinement and continuous improvement through the late '30s, it became the first practical refueling system. Sir Alan Cobham 's grappled-line looped-hose air-to-air refueling system borrowed from techniques patented by David Nicolson and John Lord, and
4564-417: A single mission, without landing to install an adapter. Other tankers are equipped with hose-and-drogue attachments that do not interfere with the operation of the centerline boom: many KC-135s are equipped with dual under-wing attachments known as Multi-point Refueling System (MPRSs), while some KC-10s and A330 MRTTs have similar under-wing refueling pods (referred to as Wing Air Refueling Pods or WARPs on
4727-480: A single scheduled rendezvous. Since then, the KC-10 had participated in other smaller conflicts. In March 1999, NATO launched Operation Allied Force against the government of Yugoslavia . The mobility portion of the operation began in February and was heavily dependent on tankers. By early May 1999, some 150 KC-10s and KC-135s deployed to Europe where they refueled bombers, fighters and support aircraft engaged in
4890-509: A small number of FRL looped-hose units and fitted a number of B-29s as tankers to refuel specially equipped B-29s and later B-50s. The USAF made only one major change in the system used by the RAF. The USAF version had auto-coupling of the refueling nozzle, where the leader line with the refueling hose is pulled to the receiver aircraft and a refueling receptacle on the belly of the aircraft, allowing high-altitude air-to-air refueling and doing away with
5053-575: A squadron of Javelin air defense aircraft was refueled in stages from the UK to India and back (exercise "Shiksha"). After the retirement of the Valiant in 1965, the Handley Page Victor took over the UK refueling role and had three hoses (HDUs). These were a fuselage-mounted HDU and a refueling pod on each wing. The center hose could refuel any probe-equipped aircraft, the wing pods could refuel
Boeing KC-46 Pegasus - Misplaced Pages Continue
5216-549: A top priority of the service. In March 1948, the USAF purchased two sets of FRL's looped-hose in-flight refueling equipment, which had been in practical use with British Overseas Airways Corporation (BOAC) since 1946, and manufacturing rights to the system. FRL also provided a year of technical assistance. The sets were immediately installed in two Boeing B-29 Superfortresses , with plans to equip 80 B-29s. Flight testing began in May 1948 at Wright-Patterson Air Force Base , Ohio , and
5379-472: Is not compatible with flying boom equipment, creating a problem for military planners where mixed forces are involved. Incompatibility can also complicate the procurement of new systems. The Royal Canadian Air Force currently wish to purchase the F-35A , which can only refuel via the flying boom, but only possess probe-and-drogue refuelers . The potential cost of converting F-35As to probe-and-drogue refueling (as
5542-496: Is powered by two Pratt & Whitney PW4062 engines, one mounted under each wing. It has been described as combining "the 767-200ER's fuselage, with the 767-300F's wing, gear, cargo door and floor, with the 767-400ER digital flightdeck and flaps". (The displays actually look like those of the 787). The KC-46 uses a similar Maneuvering Characteristics Augmentation System (MCAS) to that implicated in two 737 MAX crashes ; in March 2019,
5705-447: Is relatively light (typically soft canvas webbing) and subject to aerodynamic forces, it can be pushed around by the bow wave of approaching aircraft, exacerbating engagement even in smooth air. After initial contact, the hose and drogue is pushed forward by the receiver a certain distance (typically, a few feet), and the hose is reeled slowly back onto its drum in the HDU. This opens the tanker's main refueling valve allowing fuel to flow to
5868-413: Is simpler to adapt to existing aircraft and the flying boom , which offers faster fuel transfer, but requires a dedicated boom operator station. The procedure allows the receiving aircraft to remain airborne longer, extending its range or loiter time. A series of air refuelings can give range limited only by crew fatigue /physical needs and engineering factors such as engine oil consumption. Because
6031-479: Is used on US Navy & Marine Corps F-35Bs and F-35Cs ) added to the early-2010s political controversy which surrounded F-35 procurement within the RCAF. These concerns can be addressed by drogue adapters (see section "Boom drogue adapter units" above) that allow drogue aircraft to refuel from boom-equipped aircraft, and by refuelers that are equipped with both drogue and boom units and can thus refuel both types in
6194-507: 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,
6357-709: The Aéro-Club de France and the 34th Aviation Regiment of the French Air Force were able to demonstrate passing fuel between machines at the annual aviation fete at Vincennes in 1928. The UK's Royal Aircraft Establishment was also running mid-air refueling trials, with the aim to use this technique to extend the range of the long-distance flying boats that serviced the British Empire . By 1931 they had demonstrated refueling between two Vickers Virginias , with fuel flow controlled by an automatic valve on
6520-618: The Short Empire flying boat Cambria from an Armstrong Whitworth AW.23 . Handley Page Harrows were used in the 1939 trials to perform aerial refueling of the Empire flying boats for regular transatlantic crossings. From 5 August to 1 October 1939, sixteen crossings of the Atlantic were made by Empire flying boats, with fifteen crossings using FRL's aerial refueling system. After the sixteen crossings further trials were suspended due to
6683-601: The State Department approved the Foreign Military Sale to Israel of eight KC-46s and related equipment for a cost of $ 2.4 billion (~$ 2.78 billion in 2023). In February 2022, the United States and Israel signed an agreement to supply KC-46s to replace the aging fleet of Israeli tankers. In September 2022, Boeing announced Israel has purchased four KC-46s for delivery in 2025. The contract includes provisions to enable Israel to potentially purchase
Boeing KC-46 Pegasus - Misplaced Pages Continue
6846-618: The Vietnam War , doubts began to form regarding the Boeing KC-135 Stratotanker fleet's ability to meet the needs of the United States' global commitments. The aerial refueling fleet was deployed to Southeast Asia to support tactical aircraft and strategic bombers, while maintaining the U.S.-based support of the nuclear-bomber fleet. Consequently, the Air Force sought an aerial tanker with greater capabilities than
7009-476: The West Coast . Cobham's company FRL soon realized that their looped-hose system left much to be desired and began work on an improved system that is now commonly called the probe-and-drogue air-to-air refueling system and today is one of the two systems chosen by air forces for air-to-air refueling, the other being the flying-boom system. In post-war trials the RAF used a modified Lancaster tanker employing
7172-423: The flight envelope . At the rear of the KC-46 is a fly-by-wire refueling boom supplemented by wing air refueling pods at each wingtip and a centerline drogue system under the rear fuselage so it can handle both types of refueling in one mission. The boom includes a hydraulic relief valve system, similar to those on the KC-10 and KC-767 tankers, to relieve axial pressure in the event of excessive loads building up on
7335-433: The "receptacle" in the receiver aircraft during fuel transfer. A poppet valve in the end of the nozzle prevents fuel from exiting the tube until the nozzle properly mates with the receiver's refueling receptacle. Once properly mated, toggles in the receptacle engage the nozzle, holding it locked during fuel transfer. The "flying" boom is so named because flight control surfaces , small movable airfoils that are often in
7498-705: 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 (GAO) in March 2008 and waged
7661-511: The 22d Bombardment Wing, was re-equipped with KC-10A Extenders and became the second Air Force unit to operate the new tankers. The 60th and final KC-10 was delivered on 29 November 1988. The KC-10s served with SAC until 1992, when they were reassigned to the newly established Air Mobility Command . In the aerial refueling role, the KC-10s have been operated largely in the strategic refueling of large number of tactical aircraft on ferry flights and
7824-468: The 334th Transport Squadron. Of the 5,500 hours flown in the first three years of use, the aircraft were used in their tanker role for 50% of the time. Besides being used by the air force and NATO allies, the KDC-10s were also used to support peacekeeping and humanitarian aid operations. Of the first three years, 32% of the flight hours were used for peacekeeping and humanitarian aid. In this function,
7987-484: The A-10. At milestone C, Boeing gave the USAF a boom design that used the international standard of 1400 lbs of thrust resistance, which they accepted, but the A-10 is only able to generate 650 lbs. On 25 January 2019, the 22d Air Refueling Wing at McConnell AFB received its first two KC-46As ( 15-46009 and 17-46031 ). In February 2019, the 97th Air Mobility Wing at Altus AFB received its first KC-46. In April 2019, it
8150-662: The A330 MRTT was deemed to be the only qualified bidder to replace the CC-150. In January 2018, the Indian Air Force re-launched its air-to-air refueling procurement program, and sent out a request for information for six refueling aircraft to Airbus, Boeing and Ilyushin , to which Boeing could respond with an offer for the KC-46 Pegasus. Airbus and Boeing responded to the request for information, while Ilyushin
8313-531: The AROS has been problematic, motion viewed in the RVS versus which can create a depth compression and curvature effect. Blackouts and washouts on the displays during refueling, caused by shadows or direct sunlight are a problem that will be fixed by the RVS 2.0 upgrade along with depth perception issues via the use of new cameras and a full-color high-definition screen. Experienced boom operators of older tankers still prefer
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#17327725549848476-531: The Airbus A330 MRTT and KC-46 tankers for a future modernization program, expected to take place after the current Airbus A400M Atlas program completes. The Indonesian Air Force is said to compare the tankers on compatibility with the force's current aircraft, life-cycle costs, interoperability with current and future assets, and potential funding and technology transfer options with state-owned aircraft manufacturer Indonesian Aerospace . In March 2020,
8639-490: The Airbus A330 MRTT. South Korea selected the Airbus A330 MRTT in June 2015. Aerial refueling Aerial refueling ( en-us ), or aerial refuelling ( en-gb ), also referred to as air refueling , in-flight refueling ( IFR ), air-to-air refueling ( AAR ), and tanking , is the process of transferring aviation fuel from one aircraft (the tanker ) to another (the receiver) while both aircraft are in flight. The two main refueling systems are probe-and-drogue , which
8802-572: The Blackbird constantly leaked fuel before heating expanded the airframe enough to seal its fuel tanks. Following the supersonic dash the SR-71 would then rendezvous with a tanker to fill its now nearly empty tanks before proceeding on its mission. This was referred to as the LTTR (for "Launch To Tanker Rendezvous") profile. LTTR had the added advantage of providing an operational test of the Blackbird's refueling capability within minutes after takeoff, enabling
8965-582: The Boeing plant at Renton, Washington . Boeing went on to develop the world's first production aerial tanker, the KC-97 Stratofreighter , a piston-engined Boeing Stratocruiser (USAF designation C-97 Stratofreighter ) with a Boeing-developed flying boom and extra kerosene (jet fuel) tanks feeding the boom. The Stratocruiser airliner itself was developed from the B-29 bomber after World War II . In
9128-509: The Buccaneer's case using a bomb-bay-mounted tank and HDU. The tanker aircraft flies straight and level and extends the hose/drogue, which is allowed to trail out behind and below the tanker under normal aerodynamic forces. The pilot of the receiver aircraft extends the probe (if required) and uses normal flight controls to "fly" the refueling probe directly into the basket. This requires a closure rate of about two knots (walking speed) to push
9291-471: 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,
9454-452: The F-84's wing-tip fuel tanks. The flying boom is a rigid, telescoping tube with movable flight control surfaces that a boom operator on the tanker aircraft extends and inserts into a receptacle on the receiving aircraft. All boom-equipped tankers (e.g. KC-135 Stratotanker , KC-10 Extender , KC-46 Pegasus ) have a single boom and can refuel one aircraft at a time with this mechanism. In
9617-405: The HDU. If the hose is pushed in too far or not far enough, a cutoff switch will inhibit fuel flow, which is typically accompanied by an amber light. Disengagement is commanded by the tanker pilot with a red light. The US Navy , Marine Corps , and some Army aircraft refuel using the "hose-and-drogue" system, as do most aircraft flown by western European militaries. The Soviet Union also used
9780-457: The KC-10). A small number of Soviet Tu-4s and Tu-16s (the tanker variant was Tu-16Z). used a wing-to-wing method. Similar to the probe-and-drogue method but more complicated, the tanker aircraft released a flexible hose from its wingtip. An aircraft flying alongside had to catch the hose with a special lock under its wingtip. After the hose was locked and the connection was established, the fuel
9943-530: The KC-135. In 1972, two DC-10s were flown in trials at Edwards Air Force Base , simulating air refuelings to check for possible wake issues. Boeing performed similar tests with a 747. During the 1973 Yom Kippur War , the Air Force commenced Operation Nickel Grass to supply Israel with weapons and supplies. The operation demonstrated the necessity for adequate air-refueling capabilities; denied landing rights in Europe, C-5 Galaxy transports were forced to carry
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#173277255498410106-410: 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 (~$ 1.05 billion in 2023) pretax charge for
10269-484: The KC-46, even with its current drawbacks. In April 2014, the USAF announced that the KC-46 will be based at McConnell Air Force Base in Wichita, Kansas , with an optimistic expectation of receiving the first of 36 tankers in 2016. McConnell AFB was chosen because it had low construction costs and it is in a location with a high demand for air refueling, having KC-135s based there. In addition to McConnell AFB serving as
10432-806: The KC-46. The three tankers are to be fielded around 2020 at a cost of more than ¥20.8 billion, about US$ 173 million (~$ 201 million in 2023) per aircraft. An order for a third and fourth KC-46 was placed in October 2020. Japan ordered two additional KC-46s in December 2022, bringing Japan's order total to six. In February 2021, the JASDF conducted its first KC-46 flight. Training of Japanese KC-46 pilots began in June 2021 and Japan received its first KC-46 in November 2021. In January 2018, Indonesian Air Force officials were reported as saying they were studying both
10595-559: 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
10758-452: The KC-97, the mixed gasoline/kerosene fuel system was clearly not desirable and it was obvious that a jet-powered tanker aircraft would be the next development, having a single type of fuel for both its own engines and for passing to receiver aircraft. The 230 mph (370 km/h) cruise speed of the slower, piston-engined KC-97 was also a serious issue, as using it as an aerial tanker forced
10921-425: The SR-71. KC-10 The McDonnell Douglas KC-10 Extender is an American tanker and cargo aircraft that was operated by the United States Air Force (USAF) from 1981 to 2024. A military version of the three-engine DC-10 airliner, the KC-10 was developed from the Advanced Tanker Cargo Aircraft Program . It incorporates military-specific equipment for its primary roles of aerial refueling and transport. It
11084-552: 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
11247-492: The U.S. in October 2021. Commercial refueling companies Omega Aerial Refueling Services and Global Airtanker Service operate three KDC-10 tankers, N974VV, N235UL and N264DE, for lease. They were converted from DC-10s and provide probe and drogue refueling capabilities from wing pods similar to the KC-10. In June and July 2011, Omega Air's KDC-10 supported three Royal Australian Air Force 's F/A-18 Hornets , en route to Red Flag – Alaska . In 2019, Omega agreed to purchase
11410-466: The U.S. was forced to use the UK-based F-111s in the 1986 air-strikes against Libya . The KC-10s and KC-135s allowed 29 F-111s, along with other Air Force and Navy aircraft, to reach their targets. The KC-10 again played a key role during Operations Desert Shield and Desert Storm in 1991. KC-10s facilitated the deployment of tactical, strategic, and transport aircraft to Saudi Arabia . In
11573-488: The USAF and was on contract for 94 tankers. In early 2021, the USAF cleared the KC-46 for limited operational use. The type can conduct U.S.-based refueling only, requiring other tankers for deployments to combat areas. At the time, the KC-46 could refuel the B-52, F-15, F-16, and F/A-18, but it was not approved to service the A-10, F-22, F-35, B-1, or B-2. It was expected to be fully combat-ready by 2023. During September 2022,
11736-462: The USAF announced that all KC-10s are to be retired by 30 September 2024. The KC-10 flew its last combat sortie for the USAF on 5 October 2023. On 26 September 2024, the KC-10 flew its final sortie on tail number 79-1948 bound for the 309th Aerospace Maintenance and Regeneration Group (AMARG) at Davis-Monthan Air Force Base, Arizona. The two Dutch KDC-10s were used for both refueling and transport. They were stationed on Eindhoven Airport as part of
11899-413: 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
12062-426: 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 (~$ 401 million in 2023). Boeing would be responsible for this amount, which exceeds
12225-465: The USAF approved the KC-46 for general operational use, closing out a 15-month evaluation period. In late June 2024 the USAF completed a 45 hour non-stop flight around the globe as part of Project Magellan. The flight took off and landed at McConnell Air Force Base. During the flight it was refueled a couple of times, while it refueled other operational aircraft at various places around the world. The Japan Air Self-Defense Force (JASDF) operates four of
12388-533: The USAF began reviewing KC-46 training due to this feature. Unlike the 737, the KC-46's MCAS takes input from dual redundant angle of attack sensors and disengages with stick input by the pilot. The flightdeck has room for a crew of four with a forward crew compartment with seats for 15 crew members and in the rear fuselage either palletized passenger seating for 58, or 18 pallets in cargo configuration. The rear compartment can also be used in an aero-medical configuration for 54 patients (24 on litters). Quick ingress from
12551-431: The USAF to build jet tankers based on the Boeing 367-80 (Dash-80) airframe. The result was the Boeing KC-135 Stratotanker , of which 732 were built. The flying boom is attached to the rear of the tanker aircraft. The attachment is gimballed , allowing the boom to move with the receiver aircraft. The boom contains a rigid pipe to transfer fuel. The fuel pipe ends in a nozzle with a flexible ball joint. The nozzle mates to
12714-542: 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 (~$ 56.6 billion in 2023). Northrop and EADS expressed dissatisfaction at how the RFP was structured and threatened to withdraw, leaving only Boeing in
12877-469: The USAF would use to make its final basing decisions. On 10 January 2019, the USAF took delivery of the first KC-46, well past the original 2016 delivery date, albeit with two issues outstanding and funds withheld. The two outstanding issues were inadequate boom pressure when refueling the A-10 and glare induced distortion under certain conditions in the remote vision system (RVS). The USAF acknowledged that they failed to give Boeing adequate specifications for
13040-499: 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 a clearer set of criteria, including reducing the number of requirements from 800 to 373 in an attempt to simplify the process and allow a more objective decision to be made. In March 2010, Boeing announced it would bid
13203-522: The USSR first had it been ordered to do so. The bombers would fly orbits around their assigned positions from which they were to enter Soviet airspace if they received the order, and the tankers would refill the bombers' fuel tanks so that they could keep a force in the air 24 hours a day, and still have enough fuel to reach their targets in the Soviet Union. This also ensured that a first strike against
13366-541: The acquisition of the KC-46 due to "changed and unforeseen needs" and started the procedure to procure a new tanker, possibly from another vendor. In February 2017, Boeing stated it would bid the KC-46A for the Royal Canadian Air Force 's Strategic Tanker Transport Capability competition, which is to replace Canada's fleet of CC-150 Polaris tankers. The contract is valued at C$ 1.5+ billion. In April 2021, Airbus Defence and Space and their submission of
13529-501: The aircraft having to fly to a lower altitude to be depressurized so a crew member could manually do the coupling. This air-to-air refueling system was used by the B-50 Superfortress Lucky Lady II of the 43rd Bomb Wing to make its famous first non-stop around-the-world flight in 1949. From 26 February to 3 March 1949, Lucky Lady II flew non-stop around the world in 94 hours and 1 minute,
13692-483: The aircraft made its mission impossible without aerial refueling. Based at Beale AFB in central California , SR-71s had to be forward-deployed to Europe and Japan prior to flying actual reconnaissance missions. These trans-Pacific and trans-Atlantic flights during deployment were impossible without aerial refueling. The SR-71's designers traded takeoff performance for better high-speed, high-altitude performance, necessitating takeoff with less-than-full fuel tanks from even
13855-408: The aircraft to be refueled (very close "line astern" formation flying) has resulted in the activity only being used in military operations ; there are no regular civilian in-flight refueling activities. Originally trialed shortly before World War II on a limited scale to extend the range of British civilian transatlantic flying boats , and then employed after World War II on a large scale to extend
14018-708: The aircraft was deployed to Kosovo to evacuate refugees, to the Caribbean and Central America to provide humanitarian aid after the hurricanes Luis , Georges and Mitch and to various countries in Africa and Asia to provide development aid . In 1998, the aircraft were used to evacuate Dutch citizens from Indonesia during the Fall of Suharto . Dutch KDC-10s operated out of Manas AFB in support of allied forces during Operation Enduring Freedom and in support of Allied Air Force over Iraq and Syria. A third DC-10, registered T-255
14181-449: The aircraft's fuselage and causing damage. The other major difference with this system is that when contacted, the hose does not "retract" into an HDU. Instead, the hose bends depending on how far it is pushed toward the boom. If it is pushed too far, it can loop around the probe or nose of the aircraft, damage the windscreen, or cause contact with the rigid boom. If not pushed far enough, the probe will disengage, halting fueling. Because of
14344-409: The aircraft's fuselage. Some tankers have both a boom and one or more complete hose-and-drogue systems. The USAF KC-10 has both a flying boom and a separate hose-and-drogue system manufactured by Cobham . Both are on the aircraft centerline at the tail of the aircraft, so only one can be used at once. However, such a system allows all types of probe- and receptacle-equipped aircraft to be refueled in
14507-416: The area in which contact with the boom is safe. Moving outside of this envelope can damage the boom or lead to mid-air collision, for example the 1966 Palomares B-52 crash . If the receiving aircraft approaches the outer limits of the envelope, the boom operator will command the receiver pilot to correct their position and disconnect the boom if necessary. When the desired amount of fuel has been transferred,
14670-459: The baggage compartments below the main deck. The extra tanks increase the KC-10's fuel capacity to 356,000 lb (161,478 kg), nearly doubling the KC-135's capacity. The KC-10 has both a centerline refueling boom —unique in that it sports a control surface system at its aft end that differs from the V-tail design used on previous tankers—and a drogue-and-hose system on the starboard side of
14833-574: The bombers' airfields could not obliterate the US's ability to retaliate by bomber. In 1958, Valiant tankers in the UK were developed with one HDU mounted in the bomb-bay. Valiant tankers of 214 Squadron were used to demonstrate radius of action by refueling a Valiant bomber non-stop from UK to Singapore in 1960 and a Vulcan bomber to Australia in 1961. Other UK exercises involving refueling aircraft from Valiant tankers included Javelin and Lightning fighters, also Vulcan and Victor bombers. For instance, in 1962
14996-494: The boom. In order to address the stiff boom issue, which keeps a KC-46 from refueling lightweight, thrust-limited receivers like the A-10, Boeing is replacing the current actuator with one using a pressure-flow PQ valve in the 2023 time frame. Rather than using a single boom operator seated or prone at the tail looking out a window, the Aerial Refueling Operator Station (AROS) seats two operators at
15159-528: The brothers John, Kenneth, Albert, and Walter Hunter set a new record of 553 hours 40 minutes over Chicago using two Stinson SM-1 Detroiters as refueler and receiver. Aerial refueling remained a very dangerous process until 1935, when brothers Fred and Al Key demonstrated a spill-free refueling nozzle, designed by A. D. Hunter . They exceeded the Hunters' record by nearly 100 hours in a Curtiss Robin monoplane, staying aloft for more than 27 days. The US
15322-666: The conflict. The KC-10 flew 409 missions throughout the entire Allied Force campaign and continued support operations in Kosovo . Since 11 September 2001, KC-10s had flown more than 350 missions guarding U.S. skies as a part of Operation Noble Eagle . During Operations Enduring Freedom and Iraqi Freedom , KC-10s flew more than 1,390 missions delivering critical air refueling support to numerous joint and Coalition receiver aircraft. As of 2004, KC-10s were expected to serve until 2043. The Air Force considered retiring its fleet of KC-10 tankers in response to sequestration budget cuts as part of
15485-405: 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
15648-564: The contract over Airbus) 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,
15811-455: 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
15974-427: The conversion were initially estimated at $ 89.5 million (FY 1994). The aircraft were to be equipped with both a boom and a probe and drogue system. Because McDonnell Douglas did not have any experience with the requested Remote Aerial Refueling Operator (RARO) system, and because the third aircraft differed from the original two, the program could not be completed at budget. By omitting the probe and drogue system and
16137-585: The development of Alexander P. de Seversky , between two planes occurred on 25 June 1923, between two Airco DH-4B biplanes of the United States Army Air Service . An endurance record was set by three DH-4Bs (a receiver and two tankers) on 27–28 August 1923, in which the receiver airplane remained aloft for more than 37 hours using nine mid-air refueling to transfer 687 US gallons (2,600 L) of aviation gasoline and 38 US gallons (140 L) of engine oil. The same crews demonstrated
16300-480: 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
16463-402: The drogue under the appropriate pressure (assuming the tanker crew has energized the pump). Tension on the hose is aerodynamically 'balanced' by a motor in the HDU so that as the receiver aircraft moves fore and aft, the hose retracts and extends, thus preventing bends in the hose that would cause undue side loads on the probe. Fuel flow is typically indicated by illumination of a green light near
16626-454: The earlier Boeing KC-767 tankers that were delivered from 2008 to 2010. In October 2015, Japan selected the KC-46, with a contract for three tankers expected in 2016. The decision allows for common operations and training with the USAF. Japan was reportedly attracted to its capability to refuel MV-22 Osprey tiltrotors , which the JASDF is to receive. Airbus declined to bid its A330 MRTT as they viewed Japan's request for proposals as intended for
16789-448: The early stages of Operation Desert Shield, aerial refueling was key to the rapid airlift of materiel and forces. In addition to refueling airlift aircraft, the KC-10, along with the smaller KC-135, moved thousands of tons of cargo and thousands of troops in support of the massive buildup. The KC-10 and the KC-135 conducted about 51,700 separate refueling operations and delivered 125 million gallons (475 million liters) of fuel without missing
16952-468: 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 (~$ 1.58 billion in 2023) pre-tax charge (since it won
17115-482: The first Reserve-led KC-46A main operating base, with an anticipated arrival of the KC-46As at Seymour Johnson in fiscal year 2019. Tinker Air Force Base , Oklahoma; Westover Air Reserve Base , Massachusetts; and Grissom Air Reserve Base , Indiana, were named as the reasonable alternatives. The October 2015 announcement also stated that the USAF intended to initiate an Environmental Impact Analysis Process (EIAP), which
17278-440: The fleet's relatively young age. At first, officials claimed that the initial focus on retiring the KC-10 in September 2013 was a "trial balloon" to call attention to Air Force operating cost issues. As of early 2013, the KC-10 had a per hour flying cost of $ 21,170 and a mission capable rate of 87 percent. A FY 2015 budget plan did not include cuts to the KC-10. In July 2020, the first US KC-10 to be retired, tail number 86-0036,
17441-501: The flying boom system, along with Australia (KC-30A), the Netherlands (KDC-10), Israel (modified Boeing 707), Japan (KC-767), Turkey (KC-135Rs), and Iran (Boeing 707 and 747). The system allows higher fuel flow rates (up to 1,000 US gallons (3,800 L) / 6,500 pounds (2,900 kg) per minute for the KC-135, but does require a boom operator, and can only refuel one aircraft at a time. The probe-and-drogue refueling method employs
17604-416: 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
17767-470: The front of the tanker. AROS includes three main displays for each operator to display images from multiple multi-spectral cameras distributed around the aircraft. The central 2D/3D display provides a rear-facing view for boom refueling operations. Boom operators can execute their mission in total darkness with both aircraft blacked out. The hybrid 2D-3D system requires stereoscopic glasses to be fully effective. The Remote Vision System (RVS) that feeds video to
17930-454: The ground is available via a ladder that can be pulled down near the front landing gear. The KC-46A can carry 212,299 lb (96,297 kg) of fuel, 10 percent more than the KC-135, and 65,000 lb (29,000 kg) of cargo. Survivability is improved with infrared countermeasures and the aircraft has limited electronic warfare capabilities. It uses manual flight controls , allowing unrestricted maneuverability to avoid threats anywhere in
18093-483: The home base, up to 10 operating bases will be used by the KC-46. Crews will be trained at Altus Air Force Base , Oklahoma, which was also chosen for its limited construction needs and for its existing experience with training programs for the C-17 Globemaster and the KC-135. In October 2015, the USAF announced that Seymour Johnson Air Force Base , North Carolina, was chosen as the preferred alternative for
18256-399: The hose several feet into the HDU and solidly couple the probe and drogue. Too little closure will cause an incomplete connection and no fuel flow (or occasionally leaking fuel). Too much closure is dangerous because it can trigger a strong transverse oscillation in the hose, severing the probe tip. The optimal approach is from behind and below (not level with) the drogue. Because the drogue
18419-458: The hose was connected, the tanker climbed sufficiently above the receiver aircraft to allow the fuel to flow under gravity. When Cobham was developing his system, he saw the need as purely for long-range transoceanic commercial aircraft flights, but modern aerial refueling is used exclusively by military aircraft. In 1934, Cobham had founded Flight Refuelling Ltd (FRL) and by 1938 had used its looped-hose system to refuel aircraft as large as
18582-460: The hose which would cut off if contact was lost. Royal Air Force officer Richard Atcherley had observed the dangerous aerial-refueling techniques in use at barnstorming events in the US and determined to create a workable system. While posted to the Middle East he developed and patented his 'crossover' system in 1934, in which the tanker trailed a large hooked line that would reel in
18745-478: The late 1940s, General Curtis LeMay , commander of the Strategic Air Command (SAC), asked Boeing to develop a refueling system that could transfer fuel at a higher rate than had been possible with earlier systems using flexible hoses, resulting in the flying boom system. The B-29 was the first to employ the boom, and between 1950 and 1951, 116 original B-29s, designated KB-29Ps, were converted at
18908-432: The longest runways. Once airborne, the Blackbird would accelerate to supersonic speed using afterburners to facilitate structural heating and expansion. The magnitude of temperature changes experienced by the SR-71, from parked to its maximum speed, resulted in significant expansion of its structural parts in cruise flight. To allow for the expansion, the Blackbird's parts had to fit loosely when cold, so loosely, in fact, that
19071-416: The more maneuverable fighter/ground attack types. A byproduct of this development effort and the building of large numbers of tankers was that these tankers were also available to refuel cargo aircraft , fighter aircraft , and ground attack aircraft , in addition to bombers, for ferrying to distant theaters of operations. This was much used during the Vietnam War , when many aircraft could not have covered
19234-527: The much improved probe-and-drogue system, with a modified Gloster Meteor F.3 jet fighter, serial EE397 , fitted with a nose-mounted probe. On 7 August 1949, the Meteor flown by FRL test pilot Pat Hornidge took off from Tarrant Rushton and remained airborne for 12 hours and 3 minutes, receiving 2,352 imperial gallons (10,690 L) of fuel in ten refuelings from a Lancaster tanker. Hornidge flew an overall distance of 3,600 mi (5,800 km), achieving
19397-404: The newer jet-powered military aircraft to slow down to mate with the tanker's boom, a highly serious issue with the newer supersonic aircraft coming into service at that time, which could force such receiving aircraft in some situations to slow down enough to approach their stall speed during the approach to the tanker. It was no surprise that, after the KC-97, Boeing began receiving contracts from
19560-506: The outbreak of World War II. During the closing months of World War II, it had been intended that Tiger Force 's Lancaster and Lincoln bombers would be in-flight refueled by converted Halifax tanker aircraft, fitted with the FRL's looped-hose units, in operations against the Japanese homelands , but the war ended before the aircraft could be deployed. After the war ended, the USAF bought
19723-561: The parts late. This would have again increased the cost, but in the contract for the AH-64 Apaches which the Royal Netherlands Air Force also bought from McDonnell Douglas, the price was agreed to be kept at $ 96 million. In 2010, the USAF awarded a contract to Boeing to upgrade the fleet of 59 aircraft with new Communication, navigation and surveillance and air traffic management (CNS/ATM) system. This
19886-445: The probe into the basket. Unlike the soft canvas basket used in most drogue systems, the adapter units use a steel basket, grimly known as the "iron maiden" by naval aviators because of its unforgiving nature. Soft drogues can be contacted slightly off center, wherein the probe is guided into the hose receptacle by the canvas drogue. The metal drogue, when contacted even slightly off center, will pivot out of place, potentially "slapping"
20049-585: The probe is a valve that is closed until it mates with the drogue's forward internal receptacle, after which it opens and allows fuel to pass from tanker to receiver. The valves in the probe and drogue that are most commonly used are to a NATO standard and were originally developed by the company Flight Refuelling Limited in the UK and deployed in the late 1940s and 1950s. This standardization enables drogue-equipped tanker aircraft from many nations to refuel probe-equipped aircraft from other nations. The NATO-standard probe system incorporates shear rivets that attach
20212-427: 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
20375-423: 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, Air Mobility Command stated that tests for final FAA certification were roughly 94 percent complete. Boeing announced its FAA certification in September 2018, with military certification outstanding. Aircraft refueled during testing include
20538-439: The program were estimated at $ 5 billion (~$ 5.55 billion in 2023). At the time, it was expected that the KC-46 would not be combat ready until at least late 2023. The KC-46 Pegasus is a variant of the Boeing 767 and is a widebody, low-wing cantilever monoplane with a conventional empennage featuring a single fin and rudder. It has a retractable tricycle landing gear and a hydraulic flight control system. The Pegasus
20701-414: The range of strategic bombers , aerial refueling since the Vietnam War has been extensively used in large-scale military operations. Some of the earliest experiments in aerial refueling took place in the 1920s; two slow-flying aircraft flew in formation, with a hose run down from a hand-held fuel tank on one aircraft and placed into the usual fuel filler of the other. The first mid-air refueling, based on
20864-420: The range of 35–40% have been estimated for long-haul flights (including the fuel used during the tanker missions). Usually, the aircraft providing the fuel is specially designed for the task, although refueling pods may be fitted to existing aircraft designs in the case of "probe-and-drogue" systems. The cost of the refueling equipment on both tanker and receiver aircraft and the specialized aircraft handling of
21027-408: The rear fuselage. The KC-10 boom operator cockpit is seated in the rear of the aircraft with a wide window for monitoring refueling rather than prone as in the KC-135. The operator controls refueling operations through a digital fly-by wire system . The refueling boom can deliver fuel to a receiver at the maximum rate of 1,100 gallons (4,180 liters) per minute, while the centerline drogue system has
21190-462: The receiver aircraft is topped-off with extra fuel in the air, air refueling can allow a takeoff with a greater payload which could be weapons, cargo, or personnel: the maximum takeoff weight is maintained by carrying less fuel and topping up once airborne. Aerial refueling has also been considered as a means to reduce fuel consumption on long-distance flights greater than 3,000 nautical miles (5,600 km; 3,500 mi). Potential fuel savings in
21353-545: The refueling of other strategic transport aircraft. Conversely, the KC-135 fleet has operated largely in the in-theater tactical role. There are 59 KC-10 Extenders in service with the USAF as of 2010. The USAF's KC-10s are stationed primarily at Travis AFB , California, and McGuire AFB , now part of Joint Base McGuire-Dix-Lakehurst, in New Jersey. When faced with refusals of basing and overflight rights from continental European countries during Operation El Dorado Canyon ,
21516-430: The refueling valve to the end of the probe. This is so that if a large side or vertical load develops while in contact with the drogue, the rivets shear and the fuel valve breaks off, rather than the probe or receiver aircraft suffering structural damage. A so-called "broken probe" (actually a broken fuel valve, as described above) may happen if poor flying technique is used by the receiver pilot, or in turbulence. Sometimes
21679-590: 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 (Long Range Freighter), rather than the -200ER on which Italian and Japanese KC-767 aircraft are based, differing by combining
21842-540: The same flight, such as the KC-10, MPRS KC-135, or Airbus A330 MRTT. The development of the KC-97 and Boeing KC-135 Stratotankers was pushed by the Cold War requirement of the United States to be able to keep fleets of nuclear -armed B-47 Stratojet and B-52 Stratofortress strategic bombers airborne around-the-clock either to threaten retaliation against a Soviet strike for mutual assured destruction , or to bomb
22005-541: The same year, but these early experiments were not yet regarded as a practical proposition, and were generally dismissed as stunts. As the 1920s progressed, greater numbers of aviation enthusiasts vied to set new aerial long-distance records, using inflight air refueling. One such enthusiast, who would revolutionize aerial refueling was Sir Alan Cobham , member of the Royal Flying Corps in World War I , and
22168-458: 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 (WARP) needed for full contractual Required Assets Available, they were delivered separately later. On 5 July 2016, USAF spokesman Daryl Mayer stated that, despite
22331-517: The service's FY 2015 budget. A "vertical chop" to divest all KC-10s was suggested because there are fewer KC-10s than KC-135s, having three different tanker models in service after the introduction of the KC-46 would be costly, and a "horizontal cut" across the refueling fleets would achieve small efficiencies. Some believed retiring the KC-10 would not benefit the Air Force, given that it is equipped with both boom and hose-and-drogue refueling systems and
22494-414: 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
22657-624: The transoceanic distances without aerial refueling, even with intermediate bases such as Hickam Air Force Base , Hawaii and Kadena Air Base , Okinawa. In addition to allowing the transport of the aircraft themselves, the cargo aircraft could also carry matériel , supplies, and personnel to Vietnam without landing to refuel. KC-135s were also frequently used for refueling of air combat missions from air bases in Thailand. The USAF SR-71 Blackbird strategic reconnaissance aircraft made frequent use of air-to-air refueling. Indeed, design considerations of
22820-471: The two aircraft disconnect and the receiver aircraft departs the formation. When not in use, the boom is stored flush with the bottom of the tanker's fuselage to minimize drag. In the KC-97 and KC-135 the boom operator lies prone, while the operator is seated in the KC-10 , all viewing operations through a window at the tail. The KC-46 seats two operators at the front of the aircraft viewing camera video on 3D screens. The US Air Force fixed-wing aircraft use
22983-775: The utility of the technique on 25 October 1923, when a DH-4 flew from Sumas, Washington , on the Canada–United States border , to Tijuana, Mexico , landing in San Diego , using mid-air refuelings at Eugene, Oregon , and Sacramento, California . Similar trial demonstrations of mid-air refueling technique took place at the Royal Aircraft Establishment in England and by the Armée de l'Air in France in
23146-465: The valve is retained in the tanker drogue and prevents further refueling from that drogue until removed during ground maintenance. A "buddy store" or "buddy pod" is an external pod loaded on an aircraft hardpoint that contains a hose and drogue system (HDU). Buddy stores allow fighter / bomber aircraft to be reconfigured for "buddy tanking" other aircraft. This allows an air combat force without dedicated/specialized tanker support (for instance,
23309-454: 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,
23472-444: 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 (EMD) model
23635-655: The worldwide commercial support system. Other changes from the DC-10-30CF include the removal of most windows and lower cargo doors. Early aircraft featured a distinctive light gray, white and blue paint scheme, and a gray-green camouflage scheme was used on later tankers. The paint scheme was switched to a medium gray color by the late 1990s. The most notable changes were the addition of the McDonnell Douglas Advanced Aerial Refueling Boom and additional fuel tanks located in
23798-720: Was acquired and served for three years before being withdrawn from service in April 2014 due to Dutch defense cuts and flown to Newquay Airport for scrapping. The KDC-10s in Dutch service were replaced with the Airbus A330 MRTT . The first aircraft, registered T-264/'Prins Bernhard' and due for a major service, was withdrawn from use in November 2019, prior to being transferred to its new owner, Omega Aerial Refueling Services . The last KDC-10, registered T-235/'Jan Scheffer' remained in Dutch service until October 2021. The aircraft left The Netherlands bound for service with Omega in
23961-485: Was approved by the USAF in November 2019 and were retrofitted upon delivered aircraft. By 20 December 2019, four KC-46As had received new cargo locks and the USAF had closed the Category 1 deficiency and cleared retrofitted aircraft for cargo and passenger operations. In June 2020, the 916th Air Refueling Wing at Seymour Johnson Air Force Base received its first KC-46A. By January 2021, Boeing had delivered 42 KC-46As to
24124-534: Was canceled by the DoD in January 2006. In 2006, the USAF released a request for proposal (RFP) 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
24287-582: Was chosen. The primary reason for this choice was the KC-10's ability to operate from shorter runways. Initially, a batch of 12 aircraft was ordered, but this was later increased to 60. The KC-10 Extender first flew in July 1980. In October 1980 the first aerial refuel sortie was performed. The design for the KC-10 involved modifications from the DC-10-30CF design. Unnecessary airline features were replaced by an improved cargo-handling system and military avionics . The KC-10 retained an 88% commonality with its commercial counterparts, giving it greater access to
24450-430: Was confirmed that the USAF halted all deliveries on 23 March and until further notification, as loose material and debris were found in planes already delivered. In August 2019, the 157th Air Refueling Wing at Pease Air National Guard Base received its first KC-46A. In September 2019, the USAF restricted the KC-46 from carrying cargo and passengers due to an issue with the floor cargo locks unlocking mid-flight. A fix
24613-600: Was developed to supplement the KC-135 Stratotanker following experiences in Southeast Asia and the Middle East . The KC-10 was the second McDonnell Douglas transport aircraft to be selected by the Air Force following the C-9 . A total of 60 KC-10s were produced for the USAF. The Royal Netherlands Air Force operated two similar tankers designated KDC-10 that were converted from DC-10s. The KC-10 played
24776-581: Was disqualified as the official requirement is for an aircraft with two turbofan engines. In April 2022, Hindustan Aeronautics Limited (HAL) announced that it had entered into an MoU agreement with Israel Aerospace Industries (IAI) to convert passenger aircraft into multi-mission tanker transport (MMTT) aircraft in India. In June 2014, Boeing submitted the KC-46 for the Republic of Korea Air Force 's requirement for four aerial tankers. The KC-46 competed with
24939-489: Was entitled to consideration for losses from operating the KC-135 for longer than planned. On 8 June 2016, Boeing's defense unit CEO, Leanne Caret , reported that a modified boom would be flown shortly. On 10 July 2016, Caret reported positive results from early flight tests with the revised 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
25102-470: Was eventually modified by Airspeed to Cobham's specification, for a non-stop flight from London to India , using in-flight refueling to extend the plane's flight duration. Meanwhile, in 1929, a group of US Army Air Corps fliers, led by then Major Carl Spaatz , set an endurance record of over 150 hours with a Fokker C-2A named the Question Mark over Los Angeles. Between 11 June and 4 July 1930,
25265-404: 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
25428-417: Was mainly concerned about transatlantic flights for faster postal service between Europe and America. In 1931 W. Irving Glover, the second assistant postmaster, wrote an extensive article for Popular Mechanics concerning the challenges and the need for such a regular service. In his article he even mentioned the use of aerial refueling after takeoff as a possible solution. At Le Bourget Airport near Paris,
25591-451: Was projected to total US$ 43.16 billion (~$ 54.2 billion in 2023). 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,
25754-416: Was publicly demonstrated for the first time in 1935. In the system the receiver aircraft, at one time an Airspeed Courier , trailed a steel cable which was then grappled by a line shot from the tanker, a Handley Page Type W10 . The line was then drawn back into the tanker where the receiver's cable was connected to the refueling hose. The receiver could then haul back in its cable bringing the hose to it. Once
25917-495: Was pumped. Some historic systems used for pioneering aerial refueling used the grappling method, where the tanker aircraft unreeled the fuel hose and the receiver aircraft would grapple the hose midair, reel it in and connect it so that fuel can be transferred either with the assistance of pumps or simply by gravity feed . This was the method used on the Question Mark endurance flight in 1929. The probe-and-drogue system
26080-422: Was so successful that in June orders went out to equip all new B-50s and subsequent bombers with receiving equipment. Two dedicated air refueling units were formed on 30 June 1948: the 43d Air Refueling Squadron at Davis-Monthan Air Force Base , Arizona , and the 509th Air Refueling Squadron at Walker Air Force Base , New Mexico . The first ARS aircraft used FRL's looped-hose refueling system, but testing with
26243-407: Was to allow the aircraft to fly in civil airspace as new ICAO and FAA standards took effect in 2015. Rockwell Collins was awarded a contract in 2011 for avionics and systems integration for the cockpit modernization program. The first KC-10 was delivered to the Air Force's Strategic Air Command (SAC) in March 1981 at Barksdale AFB . In 1982 a newly renamed 22d Air Refueling Wing , formerly
26406-658: 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
26569-440: Was transferred to the 309th Aerospace Maintenance and Regeneration Group (AMARG) for storage at Davis-Monthan Air Force Base, Arizona. In July 2021, the 2d ARS was the first KC-10 squadron to start conversion to the KC-46. In August 2021, the KC-10 took part in the largest non-combatant evacuation in support of Operation Allies refuge and contributing to the safe evacuation of more than 124,000 Afghan refugees. In January 2023
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