In-Flight Refueling History

by R.G. Pelley

Anybody even vaguely related to aviation is aware of the importance of Gander as a refuelling site for airplanes crossing the Atlantic, especially in the 1940s and 50s. It is easy to visualize DC6s, DC7s, Constellations and the like on the ramp as faithful employees from Shell or Esso gassed them up in rain, snow or hail.

However, very few people are aware of what happened in Gander as far as "in-flight" refuelling is concerned. Little is known of those tanker airplanes that took off from Gander to refuel another airplanes in mid-air.

Some years ago I bought a postcard showing what looked like a Lancaster bomber in Gander that had been modified as a tanker but I reckoned it was probably just some airplane passing through.  On looking at it more closely, I saw the name "Flight Refuelling" and decided to follow the trail.

But before going any further, I must say thanks to a great group of people. The international company Cobham plc, based in England, is now the parent company of the Flight Refuelling Ltd (FRL) which owned the airplane on the postcard. Cobham is engaged in the development, delivery and support of aerospace and defense technology and systems.  A first thank-you goes to Philip Smart, Brand and Digital media Manager, who so very kindly piloted all my requests for info. Colin Cruddas, archivist with the Cobham archives, was helpful to the point of even giving me access to sections of an as yet unpublished book on in-flight refueling by Brian Gardner. Their information and that from many other sources tells the story - and quite a story it is!

The "composite method" to increase flying distance

Airplanes between the two world wars were capable of flying basically only short distances. All kinds of techniques were used to enable  planes to fly farther, including low-drag steel monocoque skins instead of wood or fabric, larger fuel tanks (which could sometimes be jettisoned), and more efficient engines.

Another possibility was the "piggy-back" or "composite" solution, using two machines. The Short-Mayo composite project in Great Britain combined an S.20 seaplane, called Mercury, and a modified S.23 C flying boat, named Maia, which had been modified to accommodate Mercury atop its fuselage. On 21 July 1938, the composite took off from Foynes, Ireland, with the Maia flown by Capt. Wilcockson and Mercury by Capt. D C T Bennett (two well known names in Gander's history).  It was a successful twenty-hour twenty-minute non-stop flight to Montreal with half a ton of mail, newspapers and newsreels. The composite was used successfully for cargo, but was considered too dangerous for carrying passengers.

The following website shows it all, with the added benefit of being able to see Bennett  "in person":


Early attempts at in-flight refueling

In the meantime, mid-air refueling was being looked at and it had humble beginnings. The first real attempts were in 1921 when a U.S. Huff-Daland HD-4 used a grappling hook to snag a 5-gallon gas can from a float. In another case, a wing walker, with a gas can strapped to his back, climbed from one airplane to another to pour gas into the aircraft’s tank. 

In the US, the best known testing was done with the airplane "Question Mark", a tri-engine Fokker C-2. The flight lasted from 01 to 07 January,1929; a total of 150 hours and 40 minutes, including a flight over the New Year’s Day Rose Bowl football game. During the flight, they made 43 contacts with the tanker aircraft, each contact lasted about 7 1/2 minutes, with the aircraft about 15 to 20 feet apart.
The two refueling aircraft alternating in the operation were Douglas C-1 single-engine bi-planes with a refueling hose passed through a hatch cut in the floor.  During the refueling contacts, the tanker crews also passed oil, food, water and other miscellaneous items, by means of a rope.

Britain's early tries with in-flight refuelling

In-flight refueling research continued as well in other countries, particularly Great Britain.  In the early 1930s, Lt. Richard Atcherley of Britain’s Royal Air Force devised a new approach wherein the tanker trailed 300 feet of line with a grapnel hook at the end which then hooked a 100 ft weighted line dangling from the receiving aircraft.
Atcherley’s “crossover” method, patented in 1935, was purchased by Flight Refueling Limited, headed by Alan Cobham, who had been knighted for his work on civil aviation. The company received support from Imperial Airways and in the late 1930s developed what came to be called "the looped-hose" method. Here the receiving airplane pulled behind it a weighted line with a grapnel hook at the end. The tanker flew alongside and literally fired its own hooked line across the other to entangle the hooks.  The line was first drawn back into the tanker where the receiver's cable was then connected to the refueling hose. The receiver then hauled back in its own cable bringing the hose to it.  Once the hose was connected, the tanker climbed sufficiently above the receiver aircraft to allow the fuel to flow under gravity.

Also see: Gander's Role In Early Aerial Refuelling

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