The demands of WWII generated rapid development in allied fighter technology and performance. Gus Larard, a former RAAF F-18 pilot, has been fortunate enough to display a number of the best restored examples of these aircraft at airshows in Australia and the USA. He compares the experience of flying several of these icons.
HAWKS On the ground, the 1933 design P-40 has quite limited forward visibility due to the long high nose. At take-off power of 45 inches at 3000 RPM the V-12 Allison sounds like a hard revving tractor engine. If the tail is kept down, it lifts off without too much yaw or roll control difficulty. You don’t need to actually do anything with the P-40 to fall in love with it once airborne.
Just sit there and look around – at the famous classic canopy frame – at the WWII camouflage and markings, and at the long snout of the growling V-12. It just exudes a no-nonsense, highly reliable, solid killing machine feel. Maneuvering is fantastic – it rolls with the crisp rate and control of a jet fighter – easy to see why the AVG Flying Tiger pilots said the best tactic against the Japanese fighters following a gun attack was a half roll, hard pull then look. The opposition could never match the roll rate. The five spar wing construction with no g-limit means that if you need to turn, pull as much as your body can take – there isn’t even a g-meter fitted or needed.
The high airframe feedback makes aggressive maneuvering to the wing AOA limit, or balanced energy maintenance straightforward for a half-competent fighter pilot. In a high speed dive the P-40 will go to a stunning Vmo (for its time) of 480mph. Considerable amounts of left rudder is needed to keep the sight on the simulated target, but as long as some trim is wound in advance, it can be held rock steady for strafing – no wonder it was so feared in this role. At a cross country power setting of 28in at 2350 RPM it indicates a respectable 240mph and burns about 45 gph.
Landing – a curving base turn is best so the aim point and runway can be kept in sight, aiming to roll out just at the flare point. With 100 mph at the threshold, it can be wheeled on, or if you are current, confidently flared to reach a 3 point attitude about 90mph and it settles beautifully – heaven! Perhaps the P-40’s major limitation is the lack of a supercharged engine. Doesn’t matter much for 2010 peacetime flying operations, but does mean the Allison P-40 versions are effectively combat limited to below 17,000ft.
PONIES So much is known about perhaps the most famous fighter of all time, and there are plenty of pilots around with lots of Mustang time to talk about it. All that will be added here is a comparison of the Mustang with the P-40. There is some common ancestry between the two aircraft enginewise. Jonathan Glancey, in his 2006 masterpiece on the Spitfire, describes how a V12 Curtiss D-12 engine was disassembled under the eyes of Henry Royce, eventually leading to the development of the Rolls Royce Merlin.
Walking up to the Mustang should of course be done very slowly as the whole machine is such a work of art, and the anticipatory moments are to be savored. It is hard to believe it only took 100 days (instead of years) to get those lines looking so nice. On the ground, visibility from the P-51D is much better than from the P-40, and wide track landing gear makes ground handling straightforward. Above 45 in of boost, the famous crackling Merlin note settles into a jet like roar in the cockpit. In formation take-offs with the P-40 the 2 are dead equal in acceleration at full take-off power. As long as the tail is held down as per the USAAF Training Manual recommendation, take-off handling is easy.
Cross country cruise at 35 in at 2400 RPM gives 240 mph at about 60gph, depending on the version. Again, you don’t actually need you do anything with the Mustang, just sit here and soak it up. Those 4 magnificent paddles up front thumping away – you need to pinch yourself sometimes. Looking around – the visibility is just glorious. That bubble canopy alone must have saved so many young pilots lives from Messerschmitts and Focke-Wulfs. Looking at those pretty silver wings sends shivers through the spine. Roll handling – heavier forces are needed than the P-40, and rate is noticeably slower.
Substantially more attention is needed than in the P-40 during hard maneuvering – the laminar flow wing gives much less warning approaching its angle of attack limit, and if not well balanced with rudder, in the subtle loaded stall the aircraft can flick wildly. Not a good thing to happen during pullout from a low level display loop. Energy maneuvering – in sustained low level aeros, energy management is harder – the laminar wing bleeds energy more than the P-40’s under g – clearly this was a wing designed more for higher speeds and altitudes than for low level turning. At higher speeds though, the much more slippery P-51 will get away and top-out faster.
Of course, the P-51 has two generational capabilities the P-40 doesn’t have – with its massive 268 gallon internal and 489 gallon total fuel capacity it is a combination fighter and fuel tanker, and the supercharged Merlin extends its useful combat envelope to high altitude.
BENT WING GULLS The Corsair must take the prize for the greatest amount of fighter you get per aircraft. A masterpiece of hydraulic engineer ing, with cowl flaps, oil cooler flaps, wing fold, hook, supercharger, intercooler, and so on and so forth, there are plenty of levers and gauges to monitor. In the earlier WWII models, you sit up on what feels like a bracket in the top of the fuselage – the cockpit has no “floor”, so dropping of maps, approach charts, pens or torches can be lethal.
This is also an aircraft that deserves a thoroughly slow walk up, it possessing a similar raw menace as the Bearcat. The best part is starting Pratt & Whitney’s magnificent R-2800 18-cylinder twin-row radial. Turning the ramp ‘IMC’ in blue smoke as the cylinders slowly catch and those huge blades thrash the blue clouds rearwards is a sensory overload. It takes practice, careful attention, and experience on the individual engine to get the starts right. Visibility ahead on the ground is poor, but there is plenty of reference through the forward quarter panels to assess pitch attitude and yaw. The short coupling between the small fin and all that weight up front demands 100% attention to taxi, and to manage during crosswind take-offs and landings.
Taking off at a modern fuel power setting of 50 in at 2700 RPM generates a highly acceptable throaty roar from the R-2800, with afterburner like acceleration. As long as the tail is kept down, as recommended by the original manuals for most of these fighters, the rudder and aileron inputs needed are not too extreme. It cruises cross country at a comfortable 30 in at 2000 RPM, giving 220 KIAS at about 55gph. Again, there is no need to do anything with it but enjoy – you sit up high in the huge fish bowl canopy, with an inspiring view of that huge inverted gull wing ahead, and that very long nose leading to that famous 13 ft+ prop. At endurance power setting, you can even see the individual blades turning.
Handling wise, once you get used to the stick with the large amount of throw from the pivot in the depths of the plumbing below, it is delightful. The wings talks clearly through the airframe – even easier than the P-40 to fly to the sustained best turn AOA, or pull hard to fly at the edge of the loaded stall. Stick forces are lighter than the Mustang or P-40. Roll rate is clearly superior to the Mustang’s, though does not match the P-40’s. Lots of rudder is needed during maneuvering flight, especially with turn reversals. Not difficult to maneuver hard, but if a pilot gets a little ham fisted in pitch or behind with the rudder it will let go with a most impressive snap at the loaded stall.
Turning performance and energy maintenance feels similar to the Mustang’s. The aircraft also top ends at similar speeds to the Mustang, and has similar altitude capability. It doesn’t quite have the internal range of the Mustang, but with a significantly superior external load capability, can be amply tanked up for long range work. A major combat benefit is the radial engine. One hit in the V-12’s coolant and it is all over. R-2800s regularly brought Navy or Marine pilots home with whole cylinder blocks shot off. Again, due to the blocked forward visibility in the landing configuration, a curving base turn to the flare is necessary. Once current on the aircraft, at full flap with a 100 KIAS threshold speed the Corsair can be 3 pointed sweetly. The huge amount of drag from the barn door flaps pulls her up pretty swiftly, but again 100% attention is needed to keep it straight as the fin is largely blanked during the rollout. The long soft shock absorbing makes even a firmish touchdown feel like a greaser, enhancing pilot satisfaction – unrealistically, but most acceptably.
BEARS The Bearcat will never be described as “pretty”. Born out of an urgent operational requirement for an interceptor that could crank, launch, high speed climb and cruise to intercept inbound Kamikaze, the Bearcat was a cut-down version of the Hellcat. R-2800 powered, the weight loss regime saw the loss of 2 guns, external load capability, and most systems to maximise thrust/ weight and speed. This resulted in a quantum leap in performance.
Perhaps the most intriguing design feature is the “snap-off” wing outer sections, designed to shed the outer 40 inches of each wing at very high speeds or if more than 7.5 g is pulled. Suffice to say operational fighter pilots were not impressed with this feature and had them ‘welded’ back on. Unless the Bearcat has been lovingly polished for some time, even the dark blue Navy paint scheme cannot conceal the thick streaks of oil running from the exhaust stacks to the tail. Start-up exhaust stack fires also blow straight back to the cockpit, so do not try to look cool by starting this aircraft with the canopy open, especially if wearing a white shirt. Just like with the Corsair, starting the R-2800 is an art, as backfiring can cause serious damage.
Being seated much closer to the engine than in the Corsair with its intervening fuel tank, forward visibility is better – assuming last flight’s oil was thoroughly cleaned from the windscreen. During start, as the cylinders kick in one by one, just sit there and enjoy the clouds of blue smoke blanketing the bystanders behind for at least a solid minute. Taxiing the stubby fighter is straightforward, with the solid rubber tailwheel transmitting every bump on the surface with great fidelity. No amount of warning can prepare you for the deafening crescendo as the throttle is advanced towards the target of 50 in at 2700 RPM for take-off.
When it appears that any more sound must shake the aircraft to bits, a glance at the boost reveals still only 30 inches set – keep pushing that throttle a lot further forward. The thrust line tries to pull the nose down – the Bearcat must be held in a 3 point attitude or the 12 ft 7 in prop may strike the ground – full aft stick is needed. There is just a moment as it rolls to enjoy the deafening roar and the serious amount of muscle being used to keep all three flight controls in the far corners of the cockpit, before it lifts off. The pudgy fighter handles beautifully. Crisp roll rate – at least as good as the P-40.
A very rapid onset is available in pitch. Point it up and it just keeps going up and up. It sustains speed beautifully in hard turns – you seem to be pulling lots more g to keep it in the same piece of airspace. Vne is 425 KIAS, and unlike the earlier generation machines, it is easy to get there. The Bearcat was one of the fastest production piston engine fighter ever built, and (as narrated elsewhere in this issue) established the world climb record to 10,000 ft. This record was broken by a jet ten years later – but the jet could not take off in 115 ft. In the Bearcat, conservative, nosewheel day job pilot style tail high wheelers at speed are not an option – the geometry with that huge prop mandates a three-pointer, every time. So100 KIAS down finals, 90 at the flare, select the 3 point attitude, cross your heart, and have faith. Eventually that feeling of complete helplessness wondering whether you are at 6 inches or 6 feet altitude is relieved by that comforting lower spine crunching sensation from that solid tailwheel.
FURIES The 18 cylinder, 54 litre Bristol Centaurus engine is mechanically a leap forward from the R-2800, transmitting 2550 hp to the 12 ft 9 in Rotol prop, topping the Bearcat’s 2250hp (if water injection is used), but you get a lot more aircraft with the Sea Fury, empty/ max weights being 9250/14850 lbs versus 7600/13500 lbs. In a typical air combat configuration that gives the Bearcat a slight thrust/weight advantage, although the Sea Fury’s four 20mm cannon definitely outgun the Bearcat’s four .50 cals. In the Sea Fury, mixture and RPM are automatic after takeoff as is oil temperature control and fuel feed.
This all makes the SF as delightfully simple as a basic jet to operate. Starting the Centaurus, especially if it hasn’t been run for a while, creates a similarly satisfying amount of heavy radial entertainment, without as generous an amount of sharing of oil with the environment as the R-2800. Taxi is pretty straightforward – the Centaurus at the end of the long nose blocks the view eventually, but the thoughtful angling of the forward fuselage down from the cockpit forward must have been well appreciated by carrier pilots.
In a masterpiece of British understatement, the Pilots Notes say: “full throttle should be used on take-off even though the aircraft may become airborne before the full throttle position is reached”. Pushing the massive long throw throttle lever up to the full position gives +9.5 in of boost at 2700 RPM. Rather than the cacophony of the R-2800, the Centaurus gives a deep jetlike roar. Lots of left rudder and full aileron is needed to try and keep her straight and the wings level, as the half-ton five blade prop tries to march the aircraft off to the right. Tail is kept down as per the book.
There are only sufficient moments for the briefest check of boost, RPM, oil pressure and airspeed before you are airborne. Once the gear is up, throttle lever goes from Max to Auto where it stays for the rest of the flight. Fuel flow on the take-off roll is 300 gph (we’ve switched to Imperial now, by the way). Rate of climb indicates 4400 fpm. Pulling the throttle back to 85 gph gives the brain and heart rate some closure on catching up with the aircraft. Just trying to keep up with the raw performance of the beast takes up plenty of mental capacity; Hawker’s engineering foresight in simplifying aircraft operation is much appreciated.
In the SF, conventional control cables are replaced with push-rods and torsion bars, successfully engineered to make control forces light and steady with g throughout the speed envelope. Roll control is particularly fast and precise – out of all five aircraft, the SF feels like the best air to air gun platform. During hard maneuvering though, everything you have heard about elliptical wings comes to the fore and holds true – sustained turn performance feels better than the Bearcat, and the wing talks most loudly and clearly of any of the five fighters to the pilot about what is happening, energy maintenance and stall-wise.
This aircraft can be flown most aggressively to its sustained and instantaneous limits, and unlike most other pistons, retains easy maneuverability at high IAS, as at least one unfortunate MiG 15 pilot could briefly attest. Cross country in the Sea Fury- you can cruise it at 300 KIAS, but would not do so if paying for the fuel. 85 gph gives a comfortable 250 KIAS. Slowing to 200KIAS gives 60 gph. The Sea Fury is landed from a curving base leg. The book says 100KIAS at the threshold, and it can be flared for a non-demanding tail-low wheeler at 90 KIAS.
TAKE-HOME? So what is your choice? That will depend on entirely on personal preference, but hopefully this will at least form the basis of further research, validation and invalidation, and generally healthy debrief content. Blue skies!
Gus over Wangaratta in a P-40. (Rob Fox)
