Aerial refueling

The first mid-air refueling, based on 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.

The same crews demonstrated 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 the same year, but these early experiments were not yet regarded as a practical proposition, and were generally dismissed as stunts.

One such enthusiast, who would revolutionize aerial refueling was Sir Alan Cobham, member of the Royal Flying Corps in World War I, and a pioneer of long-distance aviation.

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, 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.

[7] 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.

[8] 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.

[10] Sir Alan Cobham's grappled-line looped-hose air-to-air refueling system borrowed from techniques patented by David Nicolson and John Lord, and 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.

[17][18] From 26 February to 3 March 1949, Lucky Lady II flew non-stop around the world in 94 hours and 1 minute, a feat made possible by four aerial refuelings from four pairs of KB-29M tankers of the 43d ARS.

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 the West Coast.

[20][21] 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.

In January 1948, General Carl Spaatz, then the first Chief of Staff of the new United States Air Force, made aerial refueling 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.

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.

[citation needed] At the end of 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.

[citation needed] 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.

This requires a closure rate of about two knots (walking speed) to push the hose several feet into the HDU and solidly couple the probe and drogue.

Because the drogue 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.

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 the USSR first had it been ordered to do so.

In the emerging Cold War climate of the late 1940s, the ability for bombers to perform increasingly long distance missions would enable targets to be struck even from air bases on a different continent.

[34][35] While development of the Avro Vulcan strategic bomber was underway, British officials recognised that its operational flexibility could be improved by the provision of in-flight refueling equipment.

[37][38] While continuous airborne patrols were flown by the RAF for a time, these were deemed to be untenable, and the refueling mechanisms across the Vulcan fleet largely fell into disuse during the 1960s.

[44] While able to strike at numerous targets inside of the Soviet Union, the inability for the Mirage IV to return from some missions had been a point of controversy during the aircraft's design phase.

This was used most effectively on 4 April 1981, refueling eight IRIAF F-4 Phantoms on long-range sorties into Iraq to bomb the H-3 Al Walid airfield near the Jordanian border, destroying 27–50 Iraqi fighter jets and bombers.

[54][55][56] In 1985, Israeli F-15s used heavily modified Boeing 707 aircraft to provide aerial refueling over the Mediterranean Sea in order to extend their range for Operation Wooden Leg, an air raid on the headquarters of the Palestine Liberation Organization (PLO) near Tunis, Tunisia, that necessitated a 2,000 km flight.

The Jerusalem Post reports that Israeli commanders have made this request to enhance the strategic deterrence against Iran, the same article reports that the US, whose air force is also taking its first deliveries of the aircraft type, has refused to move forward the deliveries while supporting Israel's deterrence; the Jpost editor writing "The US State Department approved the possible sale of up to eight KC-46 tanker aircraft and related equipment to Israel for an estimated cost of $2.4 billion last March(i.e. 5/2020), marking the first time that Washington has allowed Jerusalem to buy new tankers.

During the conflict's final week, KC-10s moved inside Iraq to support barrier CAP missions set up to block Iraqi fighters from escaping to Iran.

The publicity flight for a Las Vegas area hotel ended when the aircraft's performance had degraded to the point where the Cessna had difficulty climbing away from the refueling vehicle.