Air Mobility Command Celebrates 100th Year of Air Refueling.

The first air to air refueling took place over Rockwell Field, San Diego, California on June 27, 2023. National Museum of the USAF photo

Story by Ken Kula. Photos by Corey Beitler, Del Laughery, Dion Makowski, Don Linn, Dave Budd, John Freedman, Mike Colaner, Roland Dansereau, Scott Zeno, Tim Adams, Bob Finch, Ken Kula and various USAF photographers

On June 27, 1923, a pair of U.S., Army DH-4B biplanes accomplished the first aerial refueling in the United States. While flying formation, the top aircraft, in the lead, dangled a hose to the receiving aircraft below and behind. After the 50 foot long rubber hose was attached to the fuel tank in the bottom aircraft, a gravity-fed stream of 75 gallons of fuel was sent between the two aircraft. The first “tanker” aircraft was piloted by 1st Lt. Virgil Hine, and 1st Lt. Frank W. Seifert handled the hose. The aircraft receiving the fuel was piloted by Capt. Lowell H. Smith and crewed by 1st Lt. John Paul Richter, who grabbed the hose and attached it. This first “mission” lasted for 6 hours and 38 minutes, until an engine problem forced the receiver to land after just one refueling.

DH-4B tanker aircraft – National Museum of the USAF photo

Later the same year, a second tanker aircraft was added to more exploratory flights, and on August 27th through 29th, a flight of 37 hours and 25 minutes… with 14 air refueling, from a pair of tankers, was accomplished. British and French experiments were also taking place, but aerial refueling operations were not adopted in earnest by any military aviation arms.

Another photo of the first air to air refueling flight. National Museum of the USAF photo

In 1928, what was once a U.S. Marine Corps project for air refueling was assumed by a number of Army aviators operating from Washington D.C.’s Bolling Field. The Question Mark was a Fokker C.2 trimotor transport which was modified with greater fuel tankage and a larger reserve oil tank to feed oil-hungry radial engines. A pair of Army Douglas C-1 transports were modified with hoses as tanker support. Endurance was the main goal of this series of experiments.

The Question Mark Fokker C-2 being refueled by an Army Douglas C-1.  USAF photo by unknown photographer

Soon based on the West Coast at Van Nuys Metropolitan Airport, California, the Question Mark’s crew consisted of some familiar names… Maj. Carl Spatz (later spelled “Spaatz”), Capt. Ira Eaker, 1st Lts. Harry A. Halverson and Elwood Quesada, and S/Sgt. Roy W. Hooe. One tanker crew was Capt. Ross G. Hoyt, 1st Lt. Auby C. Strickland, and 2nd Lt. Irwin A. Woodring. A second crew was 1st Lt. Odas Moon and 2nd Lts. Joseph G. Hopkins and Andrew F. Salter. Capt. Hugh M. Elmendorf was in charge of the operation on the ground. Radio communications had still not been perfected, so flags, hand signals and other methods would have to be used. On New Years Day, 1929, the Question Mark departed, and wouldn’t land for slightly over 6 ½ days, or close to 150 hours later. The pair of tankers made 47 sorties, delivering some 5,660 gallons of fuel to the Fokker C-2. Forty-nine 5 gallon cans of engine oil were carefully passed between aircraft too. Ultimately, it seemed that aircraft engines were the limiting factor for endurance at that time.

From 1929 through the 1930s, civilian mid-air refueling was practiced as an effort to break endurance records, military use was not pursued because the need wasn’t there. However, in England, British Flt. Lt. Richard Atcherly invented a cable and hose system which greatly improved the air refueling process.

In America, the Douglas DC-1 and Martin B-10, both weighing in around 17,000 pounds each, were in production in the early 1930s. Variable pitch propellers and larger engines made long distance flight more attainable than ever. Longer endurance meant longer range, and air refueling wasn’t needed as the range of larger aircraft kept increasing on internal fuel carriage alone. In Britain though, increased range was still a need across their Empire, and trans-Atlantic flights with larger aircraft meant mid-air refueling was an option. Sir Alan Cobham set up the civilian Flight Refuelling Limited (FRL) to offer civilian tanker service for air-to-air refueling.

World War II put many concepts on hold if they were not necessary, and air refueling wasn’t a priority until towards the end of the war when the vast expanses of the Pacific Theatre had to be conquered to battle Japan. Plans were drawn up to have squadrons of B-24 bombers converted to tankers, but in the end, the B-29 bomber’s range negated those plans.

After the War ended, the relationship between the U.S. and Russia fall apart, and long-ranged strategic bombing rose to the forefront of the now-U.S. Air Force (USAF) planners. Turbojet engines proved to be thirsty, and the slow Convair B-36 was just an interim fix until the Boeing B-47 and then B-52 jet bombers would arrive.

KB-29M refueling B-29 bomber – USAF photo by unknown photographer

First USAF aerial tankers were converted B-29 bombers, designated KB-29Ms which used the Cobham cable and hose system. This system was only usable up to 190 knots, and grapple hooks were used to catch cables, and then hoses. Nuclear-capable B-29 bombers were the receivers. Boeing soon produced a flying boom refueling pipe, with twice the diameter of a Cobham hose, and thus, a higher fuel transfer rate. These were known as KB-29Ps.

Using the Cobham hose system, a KB-29M (top) refuels the Lucky Lady II B-50 bomber (bottom). USAF photo by unknown photographer

Soon, the improved B-50 bomber, a modified and upgraded B-29 itself, became the main receivers of the KB-29. Squadrons of tankers began to appear. A B-50 named Lucky Lady II became the first aircraft to fly non-stop around the world, with four in-flight refueling from KB-29s.

KB-29Ms made the first air refueling with a jet, when a RB-45 Tornado converted bomber took on fuel in 1950. By 1952, there were 20 squadrons of KB-29s in service. with the dawn of a new tanker just above the horizon… the KC-97 Stratofreighter. A bit earlier, another air refueling tool was developed – that being the hose and drogue method. Instead of dragging a hose via the earlier Cobham method, the same company developed the hose and drogue equipment. It consisted of a hose with a basket stabilizer on the end with a locking apparatus, and a needle-like receptacle of the receiving aircraft was inserted into the basket apparatus. After a solid connection, fuel flowed under pressure.

Boeing KC-97L tanker, National Museum of the USAF photo

KB-29s served into the Korean War, and the B-50 bomber was modified into KB-50 tanker. The Strategic Air Command had developed their requirements for a long range tanker, and Boeing’s KC-97 Stratofreighter soon became available. Fitted with the Boeing-developed refueling boom, an operator was prone in the tail section, and could fly the boom into the refueling receptacle on the receiver. While Korean War-vintage fighters normally used the hose and drogue method with which pilots made their own contacts with the tanker, Boeing’s flying boom was part of the SAC tanker-bomber tandem, beginning with the B-47 and on to the B-52. In fact, in 1958, the USAF standardized with the flying boom on all new aircraft. The fitting of a hose and basket was developed for receivers needing a drogue assembly, it was fitted to the boom on the ground to the end of a boom nozzle but could not be removed nor added in the air.

KB-50 refueling a trio of Century Series fighters – US Nuclear Weapons Center photo

As more jet aircraft entered Air Force service, the piston engine tankers – KB-29 and KB-50s, were soon mismatched in the speed department. The KC-97 was given a boost with a pair of turbojets on the outer wings to give a bit more speed for refueling the aerodynamically superior B-47. Ultimately, when Boeing’s new KC-135 Stratotanker jet was introduced, the KC-97s found their way in to Air National Guard units and continue to refuel tactical fighters up through the early Vietnam War years.

SAC KC-135A, 509 BW Pease AFB, New Hampshire

B-52 tanking in 1967, note the SAC blue flash with white stars color scheme.

The Boeing KC-135 Stratotanker allowed the Air Force to transport ground crews and equipment rapidly with any bomber force around the world. Paired with the nuclear capable B-52, it formed SAC’s true world-wide deterrent force. Its fuel load was a huge leap up from the KC-97’s payload. In fact, planners ordered some 744 B-52s and 732 KC-135s for their Wings, almost a 1 to 1 ratio. In 1961, SAC operated 1,095 tankers – 503 KC-97s and 515 KC-135s. The Tactical Air Command still operated over 100 KB-50s at this point.

Missouri ANG KC-97 refuels A-7D jets. USAF photo by unknown photographer

While SAC controlled much of the tanker force, the Tactical Air Command (TAC) required refueling operations, especially when the Vietnam War expanded. Fighter-bombers routinely were topped off after departure, where much of their fuel load was consumed by just climbing to their cruising altitude. The elderly KB-50s were modified with pods of hose and drogue refueling equipment and served from the late 1950s through 1964, when they were retired due to fatigue and corrosion issues.

KC-135A, 132 ARS, Maine ANG, refueling A-10s 174th TFW, NY ANG, Lake Ontario June 1983

KC-97s took over the duties for a while, but in 1961, the Air Force made the decision that SAC would control all of the KC-135 tanker assets, and the KC-97s, which shared some B-29 design features, slowly disappeared as KC-135s replaced them.

KC-135A, 57-2606, 150th ARS, NJ ANG at McGuire AFB, Feb. 1981

USAF EC-135C Command Post aircraft arriving at Fairford Air Base in Britain. Note the air refueling boom still active on the jet.

SAC assumed the airborne command post mission as part of the nuclear deterrence, where aircraft could remotely launch missiles while airborne, away from immobile ground-based command posts. Some early C-135 command and control jets flying “Nightwatch” and “NECAP” missions retained their refueling gear for flexibility; some models could receive and transfer fuel on the same mission. Air refueling capabilities kept one Looking Glass – sometimes nicknamed the Doomsday aircraft – airborne continuously from 1960 through 1990. 

USAF rescue flight, HC-130 refueling a CH-3 – USAF photo by unknown photographer

In 1965, Air Force HC-130 Hercules transports began exploring operations refueling CH-3 helicopters via the hose and drogue method. Extending the rescue helicopters’ range was key to expanding rescue missions, especially for downed air crew behind enemy lines. By mid-1966, a pair of Sikorsky HH-3s had flown non-stop from New York City’s Floyd Bennett Field to the Paris Air Show; the 4,157 miles took the better part of three days, via refueling by five HC-130P tankers.

New USAF MC/HC-130J aircraft can air refuel helicopters via the hose and reel pods on the outer wing, as well as receive fuel via a boom receptacle behind the cockpit.

USAF Special Operations forces utilize the MC-130 and HC-130 versions of the Lockheed Martin Hercules for air refueling during covert operations as well as search and rescue missions.  Air Force HH-60 Blackhawks, Jolly Green IIs and CV-22 Ospreys are refueled from these four-engined turboprops today.

C-5A approaching a Maine ANG KC-135E

Hose and drogue operations allowed U. S. Navy and Marine aircraft to refuel from KC-135s; a set of Flight Refueling Ltd. pods could be installed on the outer wings of some of the KC-135 tankers to add flexibility (these would be found again on new KC-767/KC-46s too).Before Vietnam, transports did not carry air refueling receptacles. A program to stretch the Lockheed C-141 Starlifter added refueling gear, and the new C-5 Galaxy was delivered with receiving gear. Their unlimited range, due to the refueling capability, truly added a “Global Reach” to the U.S. Air Force’s transports.

Wisconsin ANG KC-135R

ln 1979, SAC began replacing the existing KC-135As’ J57 engines with CFM-56 turbofan engines. The new engines increased power and efficiency that added range and a larger fuel offload capability for flight planners. With modified landing gear capable of handling an increase of 25,000 more pounds of gross takeoff weight (read: more fuel) and revamped avionics, the KC-135R gave SAC’s Global Reach a further boost.

Artwork by Dave Budd, Aircraft INK

KC-135R NJANG on a low and slow approach.

KC-135E, with TF-33 engines was an upgrade for many Air National Guard and Air Force Reserve units, over the KC-135A.

McGuire AFB based KC-135E of the New Jersey Air National Guard.

Other Air National Guard and Reserve KC-135As were modified with TF-33 turbofans, and while not as dramatic as the –R’s increase in capabilities, the new KC-135E offered improvements too. The Maine ANG retired the final KC-135E in air refueling squadrons in 2009, and upgraded to the -R model.

The KC-10A could receive fuel as well as offload it.

In the mid-1980s, 60 KC-10 Extenders became operational. The aircraft was a modified civilian transport design that could carry cargo, passengers and a large fuel load, all at once. The KC-10 had a flying boom, and a hose and drogue unit in its belly, allowing for both styles of refueling receptacles to be used during the same flight.

KC-10A Extender crew at work!

When used as a transport of cargo and freight, the KC-10 was a receiver as well as a tanker, therefore extending its range. When a KC-10 was involved moving a fighter squadron’s crew and equipment, along with a handful of jets, KC-135s would be used to refuel the KC-10, which would then offload to the fighters it was supporting.

In 1986, Air Force F-111 bombers, assisted by KC-10 and KC-135 tankers, struck targets in Libya as retaliation for a terrorist act. Operation El Dorado Canyon bombers and KC-10 tankers would fly for almost fourteen hours, covering close to 5,000 miles and transferred over 230,000 gallons of fuel during the mission. At some point(s) KC-135s refueled the KC-10s, which then refueled the bombers.

F-15 Eagle ready for receiving fuel from a KC-135

In 1990, Operation Desert Shield and later, Operation Desert Storm in Kuwait and Iraq again proved that air refueling offered an unbeatable boost for offensive and defensive flight operations by the USAF and allies. On August 7th, 1990 Desert Shield began when cells of F-15 Eagles, led by KC-10A Extenders, began crossing the Atlantic Ocean, heading non-stop to the Middle East area. Troops and supplies would flow over in C-141s and C-5s, refueled in the air to complete long flights directly into their wartime bases.

After the direct attacks of Desert Storm, air refueling provided key support of aircraft which had expended their fuel loads while in combat. In some well documented cases, whether due to damage or poor weather at their bases, air refueling saved crew and aircraft which would have been lost or captured.

KC-135Rs of the Air Force Reserve are managed by the Air Mobility Command.

In 1992, the Strategic Air Command was dissolved, and tankers which it commanded were reassigned to the Air Combat Command. In 1993, all Air Combat Command tanker assets were transferred to the Air Mobility Command. where they are still today, except for special mission MC/HC-130s.

Upgraded KC-135R cockpit.

The KC-135 model aircraft first flew in the late 1950s. In the early 2000s, plans for a new tanker model were made by the Air Force, which would allow for the elder Boeing aircraft to be retired. Contract issues forced the Stratotanker fleet to soldier on (with the assistance of previously unforeseen maintenance programs) for a number of years beyond their original planned retirement… and the Pacer CRAG upgrade replaced avionics on younger airframes with a more modern glass cockpit design. Unfortunately for some, the Navigator position was phased out by the new avionics. Finally, the KC-46 Pegasus won the competition and was ordered. The Boeing 767 variant began to be delivered in 2019, almost a decade after the first competitions took place.

KC-46A Pegasus has reached operational status with the active Air Force, Air Force Reserve and Air National Guard.

Artwork by Dave Budd, Aircraft INK

The New Hampshire Air National Guard’s 157th Air Refueling Wing trains Air National Guard crews on the KC-46A, as well as performs tanker Task Force duties.

The Pegasus has an automated flying boom which is flown from a station in the cockpit, doing away with the boom controls in the tail, which was the standard with the KC-97 and KC-135 programs. Today, KC-46As are found with Air National Guard, Air Force Reserve and active Air Force Wings.

McGuire AFB-based KC-10A arrives at Westover ARB in 2012.

In the early 2020s, the KC-10 fleet, down to 59 airframes, was identified as the next tanker to be retired by the Air Force. Economics was the main reason given, the aircraft were coming up for a major flight hour barrier, where a large-scale maintenance overhaul program would be needed. Most of the airframes were close to 40 years old, and evidently, the high cost to this program for a small amount of airframes wasn’t something the Air Force’s budget would tackle, so the decision to retire the type to Tucson’s Boneyard was made. By mid-2023, only a few KC-10s based at Travis AFB remain in use.

U. S. Navy MQ-25 with air refueling gear on the wing.

In 2023, talks concerning remote controlled or “un-crewed” tankers has been discussed. The U.S. Navy has already flown their MQ-25 pilotless aircraft in live air refueling missions with piloted aircraft, with assistance from a ground controller. The Air Force has called for concepts for a stealthy tanker/electronic warfare/reconnaissance aircraft which in some cases will be flown as “off-board Autonomous Collaborative Platforms”, or “un-crewed”.

Thunderbirds F-100 Super Sabre received fuel from a KC-135 with a hose-and-drogue attachment.

In 100 years of innovation, the U.S. Air Force has taken air refueling from a hands-on physical task to an automated and almost automatic level. The process of aerial refueling is part of almost every large-scale exercise, mission, and operation today. With future concepts of unmanned aircraft and stealthy designs, the appearance of the air refueling tanker may look quite different from today’s KC-135s, KC-10s and KC-46s, but the mission of transferring fuel from one aircraft to another to increase range and endurance really hasn’t changed at all.

GALLERIES OF USAF AIR REFUELING AIRCRAFT

TANKERS IN THE AIR VIEWS: