WHAT AIRPLANE IS THIS?

The Saunders-Roe SR.A/1

For several reasons, early aviation was fascinated by flying boats. Since our planet is about 70+% covered by water, an aircraft that can land on water seems to have the advantage of having airports everywhere. Even better, water airports are much cheaper to build than are land ones and permits are not needed to build a runway on the open ocean.

In practice of course, seaplanes proved less than ideal. Aircraft structures must be light. But heavy construction is required to take the pounding waves of the open ocean. Therefore seaplanes required calm ocean waters, waves less than six feet usually, or protected harbors and inland lakes or rivers to safely operate.

The construction necessary for water operation becomes excess drag and weight once the airplane is in the air. But unlike wheels, which can be retracted in flight, it is impossible to hide all the equipment needed for water operation. Tip floats can be retracted but then the airplane needs a water hull which adds drag and weight along with increased fuselage width. All are deadly to speed. Even when retracted, the heavy wingtip floats added weight to the outside part of the wing. This restricted roll rate and maneuverability.

But Saunders-Roe had been building seaplanes since about 1916. It started as S E Saunders Limited but soon gained extra backing, and a new name, from Roe. The company specialized in flying boats and made some very successful commercial models. But they wanted the military business as well. Saunders-Roe was a smallish company by aircraft standards, but some of the best aircraft can come from innovative small companies. The American P-51 Mustang is a perfect example. When it was designed and built, North American was not the largest company around. In fact, it was rather small at the time.

In 1943, Saunders-Roe saw an opportunity for a new, different aircraft to fulfill a special need. England, like America, was fighting a “two-front” war against Germany and Japan. British aircraft carriers were on the small and slow side of the operational window. Many had already been lost in the earlier war days. England did not have enough carriers left, nor were they building a lot more, to operate in the Pacific. Pacific operations required large, fast fleet carriers with long ranges.

British carriers had very short legs due to their size and heavy weight. The heavy weight was due to their having steel flight decks instead of wood as did American carriers. Of course, those steel flight decks proved invulnerable to the Japanese Kamikaze attacks of 1945 but that was in the future. In 1943, it looked like England would have to leave winning the Pacific war to the Americans.

That did not sit well with British pride or intentions. They had lost their Pacific bases; been embarrassed by countless Japanese victories over their warships (remember the Prince of Wales and the Repulse?); lost most of Burma and India was being seriously threatened. Nope, England badly wanted in on that part of the war.

Everyone knew that jets were the future’s aircraft. If England could develop a practical jet fighter that could operate from water, then this capability would go a long way towards getting England back into the Pacific war. Saunders-Roe decided that this was their opportunity.

In late 1943, they submitted a design for a single-seat flying boat fighter for use in the Pacific Theater. The British Government was interested mainly for the reasons outlined above. In May, 1944 a contract was signed for three prototypes of such a flying boat. The specification number was E.6/44 and the aircraft was given the number SR.A/1.

The aircraft was built from light aluminum alloy throughout to try to save some weight. Power was to be two Vickers F2/4 Beryl turbojets producing 3,850 lb. of thrust each. Armament was four 20mm cannon grouped in the nose, above the air intake.

But development of such a radical concept took a lot of time. It took several years to develop the engines alone. The war ended before the SR.A/1’s first flight on July 16, 1947. In the end, British carriers were able to perform limited Pacific operations as the need for them in the Atlantic ended with the May, 1945 German surrender.

The Sr.A/1 was actually a very good fighter for a flying boat. It could reach speeds just over 500 mph. But its heavy weight needed for water operations, over 19,000 pounds, reduced its climb rate to less than 6,000 feet per minute. Even though it carried about 7,000 lb. of fuel, its range was less than 1,000 miles.

The wingtip floats retracted inwards to try to increase maneuverability by taking their weight off the wingtips. But that meant extra drag as the floats could not fully retract into the thin wing. Pilot visibility was restricted due to the wide fuselage and the airplane’s turning circle was large, again due to the heavy weight.

Yes, the SR.A/1 was a good seaplane fighter. But in combat, it was going to be fighting land-based aircraft. In the 1949 days of the 640 mph F-86 Sabre and the high flying, tight turning Mig 15, the SR.A/1 would be helpless. Still, when the Korean War broke out in 1950, England thought about building more of this unique aircraft for ground attack work. But the aluminum structure could not handle heavy attack ordinance and its need for water operation, no wheels on the SR.A/1, quickly stopped that thinking. The last of the prototypes was retired in 1951.

Some ideas are just hard to give up. The British were not the last to think that a jet seaplane fighter would be a good idea. Despite the SR.A/1’s lack of performance, the American Navy tried to build one in the early 1950’s. You would think they would have noticed that every such attempt, no matter how skillfully done like the SR.A/1 project was, never succeeded.

Guess they didn’t because Convair tried to build a delta wing seaplane fighter. Instead of floats, it had skis! It was supposed to fly at Mach 1.5 but never got above 600 mph. The very high takeoff and landing speeds required for a delta wing meant that the skis vibrated so badly they almost fell off and the aircraft was nearly impossible to control at speed when on the water. If the aircraft slowed too much, it sank into the water until the wing was less than 2 inches above the surface. It could still move but any wave would put out the fire. Who thinks of these things anyway?

Someday, an effective operational seaplane jet fighter will be built. But it will use VTOL technology, composite structure and innovations not yet discovered. None of these technologies existed when the SR.A/1 was designed.

As for the clues:

In May 1944, the British Air Ministry issued a specification for a jet powered seaplane fighter for use in the Pacific war. The result was the Saunders-Roe SR A/1 with two jet engines mounted inside a very large fuselage and retractable wingtip floats." -- The contest aircraft had a very large fuselage and twin jets at the wing roots. The wingtip floats were not visible so they must have been retracted. The whole aircraft just looked like a seaplane.

"As far as we know, Sikorski never made a jet fighter." – And, as far as we know, it still never has. The XF-97 Sea Thunder was a made-up name.

The Saunders-Roe SR-53 was a delta-winged jet/rocket powered aircraft that also had a vertical tail – This aircraft existed as Saunders was still trying for military business. The SR-53 was a land aircraft that could reach over 1,300 mph, for short periods, using rocket power. Obviously, the contest airplane did not have a delta wing.

The Sea Vixen had two jet engines mounted in the wing roots and also had twin tail booms supporting a P-38 style tail with the stabilizer mounted high above the center fuselage – The Contest airplane had a conventional fuselage, not twin tail booms. The Sea Vixen was an improved model of the Sea Venom, who thinks of these names, and was a carrier/land based derivative of the DeHavilland Vampire. The Vampire was one of the most successful first-generation jet fighters.

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