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Refueling through the century

By Erin Lasley, Air Mobility Command History Office

SCOTT AIR FORCE BASE, Ill --  It may be hard to believe, but nearly 100 years have passed since the first air-to-air refueling took place in 1923. On June 27th of that year, two specially equipped De Haviland DH-4Bs took flight and one flew six hours and 38 minutes while the other served as a refueler using a gravity-flow hose. The Army Air Service saw this as a promising start until tragedy occurred on November 18, 1923, when the refueling hose became entangled around the wings of the aircraft and killed the pilot of the refueler aircraft. The Army Air Service pretty much scraped the idea of aerial refueling after the accident. 

As other countries fiddled around with the idea of aerial refueling during the 1920s, the U.S. concentrated on demobilization after World War I and the home front defense. It wasn’t until 1929 when the U.S. jumped back into the air refueling game and broke records. During the first week of January, 1929, the “who’s who” of Army Air Corps pioneers showed up to take a whack at refueling. Using an aircraft named the Question Mark, Major Carl A. Spatz (later spelled Spaatz), Captain Ira C. Eaker, Lieutenant Elwood Quesada, Lieutenant Harry A. Halverson and crewman Staff Sergeant Roy W. Hooe, flew the Fokker C-2 high winged monoplane, with two 96-gallon wing tanks, for a total of 150 hours and 40 minutes between Santa Monica and San Diego, California. While in the air, two Douglas C‑1 bi-planes with 150-gallon tanks refueled the Question Mark over the seven days of flying. This was all accomplished with ground, hand and flashlight signals as radios during 1929 were too heavy and unreliable. 

As historic and record breaking as the Question Mark refueling was, the U.S. Army was not impressed enough to provide funding. The Army Air Corps air refueling, once again, fell to the wayside. However, one man’s trash is another man’s treasure. Private and commercial pilots were inspired by the Question Mark refueling and began to outfit planes for air refueling. Two commercial pilots from Texas broke the Question Mark’s record and stayed in the air for 172 hours and 32 minutes in May 1929. By 1935, a Curtiss Robin aircraft broke the record again by flying for a continuous 653 hours and 34 minutes. Both these records were made possible because of aerial refueling.

The British also tinkered with air refueling during the 1930s. Their goal was not to extend an aircraft’s flight time, but to reduce fuel weight during take-off so an aircraft could carry more bombs. To achieve this, Flight Lieutenant Richard Atcherley developed the looped-hose aerial refueling system in 1934. With both the receiver and refueler using grapnels on cables, the receiver was able to catch the cable, reel the fuel hose in, and the refueler was then able to ascend to a higher altitude and let gravity do the work. This method made refueling easier, but the Royal Air Force had little use for air refueling as aircraft technology continued to progress.

Cue World War II and the fight in the Pacific. To wage war against the Empire of Japan, the U.S. Army Air Forces would need to fly its aircraft further than it had ever before. With the assistance of civilian contractors, the Army Air Forces experimented with new concepts of air refueling. Using modified B-24 Liberators as tankers, the Army Air Forces were able to extend the B-17 Flying Fortress’s range to 1,500 miles. However, by 1943, manufacturers in the U.S. were already stretched to the limit and were not able to construct the modified B-24s and B-17s needed for refuelings. Nor was there nearly enough time to train refueling aircrews who were needed elsewhere in the fight immediately. Fortunately, Allied forces gained enough ground in the Pacific so aircraft were able to reach their targets without refueling.

Though refueling did not play an operational role in World War II, the Army Air Forces finally did see its potential and continued to experiment with new planes and equipment. By 1948, General Spaatz made air refueling the highest priority for the new Air Force and took advantage of the latest refueling technology the British had churned out. Using the British loop-hose refueling system, the Air Force and Boeing produced 40 KB-29M tankers and 40 B-29 receivers for the newly created Strategic Air Command (SAC). The SAC leadership made the decision that all new bombers in the future would have inflight refueling capabilities.

As the Air Force fully embraced air refueling, this technology advanced more quickly. In May 1948, the Air Force began testing the probe-and-drogue system developed by Sir Alan Cobham, a British aviator. When refueling crews struggled to control the loop-hose system during bad weather and as more advanced aircraft were developed, the Air Force looked for something different. By September 1950, Boeing developed a “flying boom” which could better withstand bad weather, night refuelings, and high speed aircraft. The new boom design allowed aircraft to refuel more quickly and safely. The Air Force ordered 100 new B-29s with the new boom system and gave these aircraft the designation KB-29P.

It was not long after the advent of the boom technology that the legendary KC-97 Stratotanker with the flying boom came into existence in 1950. By 1953, SAC commanded nearly 30 air refueling squadrons with a majority of squadrons flying KC-97s.

The quick development of this technology was fortuitous as the U.S. once again found itself engaged in another conflict across the Pacific. Just a few years before, the U.S. military shipped many of its planes to the Pacific by sea and then refueled on various Pacific islands. By the time the Korean War started, the Air Force was now in a position to refuel its fighters and bombers in flight which saved valuable time. From July 4 to July 17, 1952, three squadrons of F-84Gs of the 31st Fighter Escort Wing participated in Operation Fox Peter One. The fighters traveled from Georgia to Travis Air Force Base (AFB), California, and then made the long trans-Pacific flight to Hickam AFB, Hawaii, refueling in-flight several times. From there the fighters “island hopped” to Japan and prepared for combat in Korea. Operation Fox Peter Two launched between October 1 and October 14, 1952, with fighters being refueled from the U.S. mainland all the way to Japan. Both operations were a success and a testament to the strategic importance of inflight refueling.

When fighter and bombing technology outpaced the piston-engined KC-97, the Air Force searched for new refueling technology. Specifically, a new turbojet refueling aircraft. After SAC issued a requirement for new tankers in 1953, both the Douglas and Lockheed Corporations submitted paper proposals, but only Boeing had an operational model. In 1957, the Air Force procured 29 Boeing KC-135 Stratotankers which would grow to 830 in the next two decades.

Air refueling continued to make progress throughout the 20th century, providing vital support in Vietnam, Operations Desert Shield and Storm, and other military and humanitarian operations. During Vietnam, the KC-135 enabled fighters to carry out missions over Southeast Asia and delivered approximately 1.4 billion gallons of fuel. Not only did SAC tankers deliver 28.2 million gallons of fuel during Operation Desert Shield, they also transported 74 percent of SAC’s passengers and 56 percent of its own cargo to the area.

Immediately following the tragic terrorist attacks on September 11, 2001, KC-135 Stratotankers and KC-10 Extenders were among the first aircraft to take to the skies over the U.S. to refuel fighters and protect the homeland from further aggression. These tankers, crewed by Air Force active duty, Air Force Reserve, and Air National Guard personnel, supported combat air patrols and delivered an overwhelming example of Total Force. After September 11, 2001, tankers played a critical role in Operations Enduring Freedom and Iraqi Freedom. From the beginning of Operation Enduring Freedom to 2008, tanker crews flew 37,140 sorties and offloaded nearly 1.5 billion pounds of fuel to U.S. and coalition aircraft. Those tankers in the theater and under the control of U.S. Air Forces Central flew an additional 91,382 sorties and offloaded more than 5.7 billion pounds of fuel.

Not only were tankers refueling military aircraft, they were also transporting passengers and cargo and were even being used for aeromedical evacuations. By 2007, security at Bagram Air Base (AB), Afghanistan allowed the 618th Tanker Airlift Control Center to schedule aeromedical evacuation missions on KC-135s. This additional capability decreased the patient transport time to Ramstein AB, Germany from up to two days to just 10 hours.

In today’s U.S. military, air refueling is no longer seen as a party trick with no practical use, but as a necessary tool in the war fighting and peace keeping efforts. The air refueling mission continues to expand with the development of the new KC-46 set to be delivered in 2018.