(photo credit: US Air Force)
On June 27, 1923, four US Army Air Corps officers with two
single-engine bi-planes and a 50-foot hose had a crazy idea, to refuel
an airplane mid-flight. Five hundred feet in the air above a San Diego,
California air base, the four men successfully conducted the world’s
first mid-flight aerial refueling of an airplane.
the short range of aircraft at the time could be extended, 1st Lt.
Virgil Hine piloted the first plane while 1st Lt. Frank Selfert dangled a
hose, which 1st Lt. John Paul Richter managed to grab from a second
plane piloted by Capt. Lowell H. Smith. The four airmen successfully
transferred 75 gallons of fuel between the two planes, proving that the
unusual fete was indeed possible.
Two months later, Smith and
Richter attempted the experiment once again, this time setting the
record for longest flight, keeping their bi-plane in the air for 37
hours using nine mid-air refuelings. Two months after that, the
practical use of the method was demonstrated when the same crew flew
from the Canadian border on the United States’ west coast down to the
Mexican border, refueling twice along the way, using the “dangle and
grab” method first attempted months earlier.
In 1929, several US military pilots made an even more daring
demonstration for their military command, hoping to sell the idea as the
future of long-range air warfare. On New Year’s Day, the airmen managed
to stay in the air for 150 hours – nearly seven days. Their impressive
flight, however, was overshadowed later that year by another pair of
airmen, who set the still-standing record for the longest flight,
staying in the air for 653 hours and 34 minutes – 27 days – while being
on the receiving end of 484 plane-to-plane contacts, which delivered
fuel, oil, food and spare parts for their aircraft.
The impressive fetes and records set by these early daredevil pilots,
however, were not necessarily put into practical use. The earliest
thoughts of the technology being put to operational use was by the
British RAF, who in the early 1930s began experimenting with the
technique in order to reduce takeoff weight, enabling their planes to
use shorter (grass) runways while carrying heavier payloads. This was
necessary at the time to make up for the primitive understanding of
aerodynamics being used in airplane design at the time. For years,
however, each time refueling was seriously considered, advances in
aviation design made it unnecessary and obsolete.
In World War II mid-air refueling was nearly used by the US and British
air forces for the first time as the two militaries attempted to put
Japan within range of their bombers. But each time the method was nearly
put into use, the allies captured forward air bases closer to their
target and the advent of more advanced airplanes extended the possible
range, making aerial refueling unnecessary.
In fact, at the time, aviation technology was advancing by leaps and
bounds, doubling aircrafts' previous speed and range capabilities. But
following WWII, as tensions increased between the United States and the
Soviet Union, US military planners decided they required the capability
to reach Soviet cities in order to increase their nuclear first-strike
and retaliatory abilities. With this in mind, in June 1948, 25 years
after the first primitive aerial refueling, the US Air Force created the
world’s first aerial refueling squadron.
At the time, a variation of the aerial refueling method first used by
those four US airmen in 1923 was still being used. A new method, called
the “looped-hose” system, involved a hose connected to a control cable
that was dangled from the tanker aircraft, which was latched onto by the
receiving aircraft. US military planners and engineers at Boeing,
however, realized the limitations of this method within months, and
designed a system that is still one of the most popular today – the
“flying boom” system.
The flying boom, still used by air forces around the world (including
the Israeli Air Force, foreign media has reported), involves a pipe
extended from the tanker aircraft, with small wings attached near the
nozzle, which is lowered and “flown” into the receiving aircraft’s fuel
bay. A second method, called, “probe and drogue," is similar to the
original hose method attempted in 1923, but does not require a crew
member to reach out of his aircraft and grab the hose. Probe and drogue
involves a hose extended from the tanker aircraft with a canvas cone
around the nozzle, which the receiving aircraft then flies a small boom
into. This method is beneficial in many ways as it allows more than one
aircraft to receive fuel at one time, as well as allowing helicopters to
Aerial refueling has been used in military operations since the Korean
War. During the Cold War especially, mid-flight refueling allowed heavy
bombers carrying nuclear weapons to remain in the air 24 hours a day,
ensuring the US the capacity to strike the USSR, although that need was
later replaced with the advent of Inter-Continental Ballistic Missiles.
For Israel, mid-air refueling has been used in the past operationally
and would be necessary for any strike on Iran, according to foreign
media analysts. While the techniques and technology for aerial refueling
of aircraft have come a long way since the first attempt in 1923, the
basic idea has remained the same, today becoming a vital part of nearly
every advanced air force in the world.