AIRBORNE AIRCRAFT CARRIERS; WINGTIP COUPLING GIVING A FREE RIDE TO FIGHTERS
INTRO
In this chapter, you will read about the concept of the Post-War Airborne Aircraft Carriers. During WWII, the USAF’s long-distance bombers’ flight- range made huge leaps forward with every new model that came out. Rapid technological development in Aero Engine Power output allowed upscaling to unprecedented dimensions of the airframe, wings, and internal fuel tanks. All that extra fuel stretched the flight range from less than 3,000 in 1940 to over 6,000 miles by the end of the war!
While the mid-war (1943) launched B-29 Flying Fortress had a max flight range of almost 6,000 miles, the post-war B-36 Peacemaker (operational from 1948-1958) could perform with a max flight range of 10,000 miles/ 16,000 km.
In contrast to that development, the first generation of (post-war) Jet Fighters had a reputation as true “Gas-Guzzlers” and therefore had extremely short flight-ranges. Even the mounting of wingtip tanks and/or belly/wing-mounted tanks hardly brought any relief that could help those fighters escort the strategic Bombers during the Cold War on their long intercontinental flights (read to Russia and back).
The photo above shows history’s first in-air coupling of two separately flying aircraft and, subsequently, the smaller aircraft’s engine’s switch-off. A Douglas C-47 and a Culver Q-14 Cadet made physical contact during the flight in a ‘hook up’ with a pin and a ring mounted on the wingtips.
A TRUE NOVEL CONCEPT, WINGTIP COUPLING.
This innovative concept was tested with the good old Douglas C-47 Skytrain. As from Aug 1949, Major Clarence E. “Bud” Anderson did remarkable experiments with a system of wingtip coupling of 2 aircraft while in flight. The smaller single-seater airplane Culver Q-14 Cadet had a pointed lance, backward mounted on its wingtip.
This pilot positioned his aircraft with some sharp flying just next and ahead of the C-47 RH wing. With a throttle-back of the Cadet, the lance was maneuvered into a ring, mounted on the C-47 wing tip, as such making a coupled pair (see 3 photos on top and below).
This photo above shows the Middle Ages Game style “Lance and Ring.” Those were used on the Q-14 Cadet and the C-47 wingtips to ease the flight’s coupling.
The basic idea behind the in-air coupling was to increase the aspect ratio of a wing with more wing surface from another plane, offsetting the smaller plane’s additional drag.
I.e., the smaller plane could fly ‘for free’ with its engine shut-off, like a parasite, coupled with the larger plane. There was no fuel consumption with the engine shut-off, and the hook up could bring the smaller aircraft much further than its own flight-range would allow.
FLIGHT RANGE EXTENDER
If the USAF planned to extend this inventive plan to a Long-Distance Bomber, such a plane could tow 2 fighters on its both wingtips, flying the smaller Jets as “freewheeling” with their own engines shut-off, towed by the Mothership.
The “awakening to action” was effectuated when needed with an imminent enemy threat. The mothership hardly sacrificed on its max range and speed with the towing, while it had two fighters in direct close support, in case hell might break loose with Bandits/Migs showing up at the horizon.
The “bodyguard” Jets would fire up their engines, uncouple from the Master, start the interception, and beat the Iwans out of their airspace. After the pounding, they could return to hook on again for a drink or two in the shape of a free refill of their tanks (and oxygen) via the mothership.
The photo above depicts the idea of the flying Aircraft Carrier that was born and developed into a steady program of testing and upscaling of aircraft. The EB-29 Super Fortress that was coupled to two EF-84 D’s Thunderjets
FLYING AIRCRAFT CARRIER
While the C-47/ Q-14 experiments were successfully continued into 1949, the more serious tests came with Project Tip-Tow, involving the much larger EB-29 Super Fortress coupled to two EF-84 D’s Thunderjets in April 1950.
The coupling mechanism became more complex. An electronic autopilot was added. The coupling lance could transfer jet fuel and oxygen to the ‘slave’ Fighters, keeping their pilots in high alert and their fuel tanks fully topped-off at any time.
A severe accident hampered the development when a left-wing tip coupling was made between an EB-29A and an F-84D. Right after the autopilot was switched on, the F-84D nose pitched up, and the Thunderjet rolled suddenly to the right over its fixed coupling or “hinge” with the mothership. In that flip, the F-84 turned upside down and hit the outer wing panel of the B-29.
Explosive bolts for jettisoning the F-84 went off but too late to release the Fighter in time and prevent her from slamming into the Bomber’s outer wing. The Super Fortress’ left-wing folded due to the impact, and the combo crashed. Fighter pilot John Davis and 5 crew members in the B-29 were killed in this fatal accident.
UPSCALING FROM THE B-29 TO THE B-36 CONVAIR PEACEMAKER
After the fatal accident, the experiments were to be continued as Project Tom-Tom in 1955/56, this time using the much larger Convair B-36 Peacemaker as the mother ship, with the RF-84 F Thunderflashes as slaves (see photo below).
The basic idea was that a single USAF bomber would fly out to drop an (Atomic) Bomb on Moscow. For such a mission, a flight of hours over enemy territories was required before arriving over Moscow.
Surviving such a flight unharmed, that was not a very realistic scenario. And definitely not in the early 1950s, while the B-36 with piston-props propulsion had a max speed of 700 km/h, where its most likely adversary, the MIG-15, flew well over 1,000 km/h.
The option of having an escort of 2 Body-guards/Fighters on each wingtip would give a comfier feeling to the crews for making it all happen. But in the end, it would remain a hazardous operation to fly with such a vulnerable “Trio of Assasins” into the Lions’ Den.
After 1955, that idea of delivering an Atomic Bomb on the USSR, employing a Long-Distance Bomber with 2 or more Body Guard Jets for protection, was no longer relevant. The German V-2 Missile had matured, and 10 years after WWII had ended, the InterContinental Ballistic Missiles (ICBM) and the Submarine-Launched Ballistic Missiles (SLBM) arrived on the scene.
There was no more need for developing the concept of the coupled flights. But what remained was the search for Interceptor Jets flight-extension to give them more autonomy of operations. But for that purpose, a new phenomenon came up, the Aerial Refuelling Aircraft or Airborne Tanker.
The photo above depicts one of the experimental flights, part of the Project Tom-Tom in 1955/56, this time using the much larger Convair B-36 Peacemaker as the mother ship, with the RF-84 F Thunderflashes as slaves.
ARRIVAL OF THE AIRBORNE TANKER
In the end, all coupling tests came to a halt, as the larger long-distance Airborne Tankers based on the modern heavy Bomber designs arrived on the scene. It was the Tanker-converted Bomber aircraft that could give the much-wanted flight-range extension to the thirsty escorting Jet Fighters. This was less complex and risky in coupling with a ‘Flying Boom’ and could bring about many more fighters for protecting the slower Bombers.
Of 1950, the KC-97 Stratofreighter was the first large-scale operated strategic aerial refueling Tanker, a variant of the Military Cargo transport C-97. The passenger transport version was also known as the mighty Boeing Stratocruiser B-377 developed straight from WWII Fame’s B-29 Superfortress.
Below you’ll see a 1947 advertisement of the Boeing Factory, comparing the legendary Boeing B-29 Superfortress with its post-war offspring, the Boeing B-377 Stratocruiser, which had its maiden flight in July 1949.
The initial order of 20 aircraft came from Panam, but the model was no commercial success, with only 56 built for various reasons. The DC-4/6/7 and (Super) Constellation swept the civil long-range Trans/Intercontinental market in the late 1940s/early 1950s until the early 1960s..
But Boeing had more success with the Miltary version as the C-97 Stratofreighter (60 built), but the real winner was the KC-97 (811 built). This long-distance Aerial Tanker aircraft KC-97 would indirectly lead to the Flying Aircraft Carrier concept’s demise with the coupling system of a Jet fighter on every wingtip, along with the arrival of the ICBMs and the SLBMs.
(Photo & Info Courtesy: Clarence “Bud” Andersen, Goleta Air & Space Museum)
Photo above depicts a post-war ad by Boeing for its Stratocruiser B-377.
The aircraft had the wing design from the iconic B-29, but a double-bubble fuselage and the Pratt & Whitney Wasp Major R-4360 engines for carrying bigger loads, more passengers and more fuel over longer distances, up to 4,200 miles. But the aircraft was not successful in the civil market: too complex, too expensive, and engines too capricious. So in the end, only 56 were produced.
CONCLUSION
This concept of the airborne Gas Station is still operational and widely used by most Air Forces all over the World to extend the flight range of their Jet fighters. The more advanced Fighters have Jet engines with way better fuel economy than what they used to have in the 1950s. But that edge has been traded in for more speed with afterburners and way more payload for carrying awesome weapons systems. With the (ever) relatively short flight range of any Interceptor Jet being a reality, the Airborne Tanker is nowadays an indispensable tool in modern air-superiority strategies.
END
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Enjoy, Hans Wiesman
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see my email to you of today re this subject
best, Hans