WWII saw massive, revolutionary engineering development, and by 1945 the future of combat aircraft lay with the new jets, but there were some superlative and fast piston powered fighters being designed, developed and a lucky few entering service. James Kightly surveys some of the most important and remarkable examples, and highlights significant survivors, as well as noting those gone forever.
By 1945 the fighter aircraft had reached a level of performance that we now know as the peak available to aircraft fitted with conventional piston engines. These engines themselves were also at the peak of development for reliable reciprocating machinery. The rate of development meant that the preceding half-decade had seen remarkable acceleration of design, systems and performance, as well as entering a regime where aerodynamics and metallurgy faced challenges hitherto unseen.
As is clear today, the future for combat aircraft was with the jet engine, but there was a twilight period when the best piston-engine fighters offered capabilities that the early jets could not. It is generally agreed that the Hawker Sea Fury and the Grumman F8F Bearcat were the ultimate production piston-engine fighters that entered service (see page 36 and 61) and there are numerous examples of both types preserved airworthy and static around the world. Bearcats have been rarer in the air, ironically, as Furies have been a cheaper option to restore and operate in the US. It was only last year that we got to see a gathering of five Bearcats at Chino.
Meanwhile, there were many other designs that were conceived or built in this period which could have been contenders for the title. Many were of conventional construction and layout, but there were many unusual designs as well, some offering particular advantages that sometimes remained unexploited.
Making the most of Meredith Several nations came up with potentially excellent designs which were not developed. Australia famously had the CAC CA-15 (see Flightpath Vol.19 No.3) and leading into that design was CAC’s development of the Boomerang (see page 30). Of similar layout to the CA-15 was the Martin Baker MB-5, another example of progressive design development, resulting in a remarkable high performance fighter with numerous useful innovation in the cockpit design and serviceability – to mention just two – which was unable to gain a production contract.
Both prototypes were scrapped, and are both much lamented by enthusiasts. Both the MB-5 and CA-15 had very obvious Meredith Effect radiator ducting configurations whereby the engine cooling provided a net thrust rather than drag, bubble canopies (the best option in 1945) and square cut tapered wings. The original of this layout was of course the P-51 Mustang, the late war developments of which followed two routes – the P-51H and example of the regular impulse to develop a ‘lightweight’ fighter and the P-82 Twin Mustang, a contrasting innovation to achieve extraordinary range, but later to find a niche as a night fighter.
While the Commemorative Air Force (CAF) operated F-82 has been returned to the National Museum of the USAF, there is some hope of seeing a Twin Mustang and there are a couple of P-51H models airworthy in the US, if elusive.
Thirties stalwarts By 1945 the Spitfire was still recognizably the same aircraft that had first flown in 1936, nearly a decade earlier, but with significantly greater performance. Bubble canopy, Rolls Royce Griffon engine and many other innovations made it essentially a new aircraft in an old shape, and even that shape was to change. A new wing, as seen on the twenty-series Spitfires was coupled with a new fuselage making the Supermarine Spiteful and Seafang, again, like the MB-5 the types not being able to win orders. No twenty-series Spitfires are airworthy, but a Seafire 47 flies in private hands in the USA. There are a handful of static examples of both preserved, but the Spiteful and Seafang are no more.
The Messerschmitt Bf 109 was also still in front-line service in 1945, and still a competitive design, but was showing the limitations of the performance stretch more than the Spitfire. Postwar derivatives and 109G and K Messerschmitts exist in preservation, but probably shouldn’t be included in the ‘ultimate’ listing. There were other developments of established types that were contenders on this plateau. The Focke Wulf Fw 190, first flown in 1939, had been developed into the Fw 190D and Ta 152, both among the best German fighters of the war’s end, the D model being seen as an interim before the more developed Ta 152 came on line. A single Ta 152 exists in the NASM collection, while there are three surviving Fw 190D models, the Flying Heritage Collection example, Wrke Nr 836017, being regarded as airworthy but has not been flown since restoration in the 1990s.
The Republic P-47N looked like the earlier P-47, but with a new wing. This internal-tanked wing proved successful in extending range to about 2,000 miles (3,200 km), and the squared-off wingtips improved the roll rate. The P-47 had been the fastest diving American aircraft of the war, reaching 550 mph and claims by pilots (due to pitot head misreadings) of going supersonic. Half a dozen P-47Ns survive, one under restoration to fly with the CAF. Meanwhile the Russians had developed several stalwart designs to a highly competitive standard – the late Lavochkin series, as seen on page 64 being one example.
Super Navy Another development of an essentially conventional aircraft (albeit with an unusual wing) was the late Goodyear F2G Corsair, another bubble-top that failed to reach mass production. Goodyear test pilot Don Armstrong recorded the type as “Like a homesick angel”. Unlike many other of these ultimate developments, a couple of F2G ‘Super’ Corsairs had a brief but effective post-war racing career. Cook Cleland’s NX5588N won the 1947 Thompson Trophy Race and the 1949 Tinnerman Trophy Race. Three F2G Corsairs survive, including Cook’s, which is airworthy.
As well as the conventional F8F Bearcat, Grumman had also developed the Grumman F7F Tigercat. Grumman’s object was to produce a fighter that out-performed and outgunned all existing fighter aircraft and that was also effective in ground attack capability. They succeeded, as the Tigercat was one of the highest performance piston-engine fighters, with a top speed well in excess of the US Navy’s single-engine aircraft, being over 70 mph faster than a F6F Hellcat at sea level. The head-on view illustrates partly how the Tigercat managed it. As well as a number of static examples, there has been a renaissance in Tigercat numbers, just like the Bearcats. However Tigercats owe their survival to many years use as firefighting aircraft.
Twins , Pushers & Oddities Another conventional layout twin that is often cited among the best fighters was the de Havilland Hornet and Sea Hornet family. Captain Eric Brown recalled: “For aerobatics the Sea Hornet was absolute bliss. The excess of power was such that manoeuvres in the vertical plane can only be described as rocket like. Even with one propeller feathered the Hornet could loop with the best single-engine fighter, and its aerodynamic cleanliness was such that I delighted in its demonstration by diving with both engines at full bore and feathering both propellers before pulling up into a loop!” Sadly only parts survive.
But the ultimate twin piston-engine fighter was probably the Dornier Do 335 Pfeil. From a company building marine aircraft and a fast bomber at the war’s start, the ‘Arrow’ seems an oddity, but was the result of Dornier development of shaft-driven pusher propellers. The 335 had excellent handling characteristics and avoided many of the engine asymmetry issues that twins usually faced, and was very fast, famously outpacing chasing Tempests at the war’s end and a captured example leaving behind the P-51 Mustang escort postwar. Only one survivor, restored in Germany and on show at the NASM Udvar Hazey in Washington, DC. The Dornier was not the only pusher contender, the Japanese Kyüshü J7W1 Shinden being another unusual pusher design.
Another pusher type worth mentioning is the SAAB J-21. While not among the fastest fighters by any means, it was the only aircraft that saw service with piston power, and after much modification (but still essentially the same design and configuration as the J-21R) with jet power, bridging the piston-jet revolution. Several SAABs survive in Sweden, while the second (unflown) prototype Shinden is in store with the NASM.
Racing and records While all the piston engine powered fighters were eclipsed by jets in a short period, there were two areas where they were still pushing the envelope. Firstly an exclusive group of racers fly every year at the Reno National Air Races in Nevada, and the majority of the ‘Unlimiteds’ are still selected from the top fighter types of the late, and just post, WWII period.
Here, Furies annually battle Bearcats with massively modified Mustangs still holding ground, while a selection of other exotics occasionally appear. Secondly there was the piston-power absolute air speed record, competed for over a twenty year period. In 1969 Darryl Greenamyer broke the 30-year-old speed record for piston-engine aircraft held by the German Messerschmitt Me 209 when he reached 483 mph. In 1979, Steve Hinton, the well known race pilot, took the heavily modified Griffon-powered Mustang RB-51 Red Baron out and broke the existing record with an average 499.018 mph, frustratingly close to 500 mph. With further engine development and ideal conditions, the RB-51 could have exceeded 525 mph, but was lost at that year’s Reno races.
The tweaked, streamlined and re-engined Bearcat Rare Bear, flown by Lyle Shelton took the record on August 21, 1989 at 528.33 mph. Some of those top fighters are still showing what engineering ingenuity is capable of.
The XP-47N Thunderbolt, showing the square-cut wings to advantage. (NMUSAF)
