• Freeware Focus On Kirk Olsson's Sabre

    Freeware Focus: Kirk Olsson North American F-86 Sabre

    By Andrew Herd (1 May 2006)

    North American, having almost accidentally delivered the world one of its greatest piston engined fighters in the form of the Mustang, found itself watching the development of the jet engine with great anticipation. Sketches of single and twin fuselage jet powered Mustangs were being made as early as 1943, but by the following year the decision had been taken to develop a jet fighter from scratch, under a contract which would deliver hulls to both the Army Air Force and the Navy - the latter aircraft being known as the Fury. By June 1945 an XP-86 mock-up was in existence, with the cockpit positioned ahead of the leading edge, above an intake duct that roller-coasted over the nosegear, under the pilot's feet and then back up to the engine; but despite winning approval, this prototype had straight wings, which meant that it was little faster than the P-84 or even the P-80 at around 560 mph.

    At NAA the design team was lead by Lee Atwood and Ray Rice and in their quest for speed, this pair found it hard to ignore the rumors that the swept wings on German jets got around the (at the time) ill understood problem of compressibility. In fact, the data needed to design swept wings had been in the public domain for several years at that stage, but the war had distracted Allied aerodynamicists and it wasn't until teams had been despatched to comb through the technological rubble of the Third Reich that serious attention began to be paid to the idea. Between the jigs and the reels, the XP-86 was rebuilt with a 33 degree swept wing and to the astonishment even of Atwood and Rice, proved capable of 613 mph in level flight - interestingly, its gross weight was only slightly more than that of a P-47. The customers were impressed and the initial order for 33 hulls was rapidly converted into one for 221, which may or may not have been helped by the frequent sonic booms that could be heard around LA at the time, as NAA test pilots experimented with half rolls and diving pull-outs. The first production example flew as a P-86A on May 20, 1948, becoming an F-86A when the designations were changed four weeks later and that September, an F-86A took the absolute speed record at 670.98 mph in combat ready state.

    Pilots loved the Sabre, one going so far as to describe it as the only plane he ever totally trusted. The outbreak of the Korean war ensured that phenomenal numbers were built, the only Western aircraft of the period beating it on sheer numbers being the Bell Huey. 554 As were built, powered by the GE J-47. The next model was to have been the F-86B (later redesignated F-86C and eventually F-93A), the fuselage of which was much altered to accommodate a P&W J48 Turbo-Wasp, which was a rebadged Rolls-Royce Tay, but this ended up being cancelled. Meanwhile, Sabres were shooting down MiG-15s wholesale in Korea, largely due to better pilot training, gunsights and radar, but also because the Sabre outclassed even the excellence of the MiG in many respects. The F-86E first flew in Fall 1950, with all-flying tail surfaces that improved control at high speed and 333 of these were delivered by April '52, together with 60 almost identical Canadair CL-13s. The Canadians eventually built nearly 800 Sabre 2s and 4s, using the F-86E hull as a starting point for systems and engine modifications, and the RAF took another 430. The F-86F flew in March 1952, with an uprated J47 and a modified wing with the leading edge slats removed and they built 2,540 of them in various guises, with over 300 supplied to European air forces - some later Fs were fitted with 20 mm cannon instead of the fifties which had been standard up until then. Sabres were also built in Australia, the final total reaching 112.

    A lot of lessons had to be learned when the Sabre was first pitted against Soviet jets. Although the Sabre didn't have any bad habits, the MiG-15 was faster, and had a better rate of climb and had a higher service ceiling than the F-86 - but the North American plane could turn, dive and pull out faster, which meant that as long as US pilots started with an altitude advantage, they could initiate and break off combat at will. F-86 pilots also benefited from having air conditioning, G-suits and far better gunsights and radar than their enemies, together with far better training, which tipped the balance substantially in their favor. The A model had cable controls, which meant that it might not be possible to recover a dive commenced above 35000 feet until the plane was in the denser air under 20000, a problem which was fixed by installing hydraulic controls in the E. Another problem was that damaged MiGs frequently escaped back across the Yalu River, which US pilots were forbidden to cross until November 1950 and on top of that, fuel was always a problem - to the extent that many pilots ran so low they experimented with shutting down the engine at altitude, gliding back to base and then relighting to complete the circuit. Hair raising stuff.

    The amazing Kirk Olsson, who earned an early place in our Freeware Focus series, given his tremendous commitment to Flight Simulation, has just released his best package yet, featuring two versions of the F-86 in a ton of different liveries. As you can see from the screenshots, its is no understatement to say that this is his best package yet and in this reviewer's opinion, the best Sabre ever released for Flight Simulator.

    The package is a 28 Mb download and comes complete with a self-installer that means that even the most inexperienced simmer should be able to set the plane up. When the installer is done, the package creates a new program group with an uninstall icon, the documentation being found in the .zip file - there isn't much, just a couple of text files, but the addon is simple to fly and you won't need any more. In addition to a list of fairly standard hot key combinations, there are a few words on how to takeoff and land and that is it; since a great deal is available about the F-86 on the web and in print, you can look forward to having fun doing some additional reading, because the Sabre belonged to the last generation of planes that depended more on their pilots than computers to stay airborne.

    Two variants of the Sabre are included in the pack: one with a 'hard' wing, and one with slats. The hard wing version is provided with eleven different liveries, including seven US schemes, and one each for the Japanese, Norwegian, Yugoslavian and Korean air forces. The slatted model introduces a real mixed bag of Canadian, German, Norwegian, Pakistani, Korean and South African F-86s, along with even more American liveries, for a total of 18 schemes. You could hardly want for more, but Kirk's kind inclusion of some paint help files will doubtless make this addon a target for advanced repainters.

    The visual model is... well, perhaps the best way to put this is that if payware developers always delivered the same quality, reviewing would be a much easier process, but the long and the short of it is that I am hugely impressed. Every inch of the airframe has clearly had Kirk's full attention, the result being absolutely stunning and the Sabre has the best visual model I have ever seen on a freeware plane, period. The fine detail in the cockpit, the gear bays and around the air brakes and control surfaces has to be seen to be believed and the quality of the textures is up there to match - you could spend hours looking at all the planes, appreciating all the hard work that has gone into them, and I did. Animations include the pilot - who ducks as the canopy opens - the slats, air brakes and a 'parking mode, which puts the engine covers in place and chocks the wheels. The slat operation is particularly neat and is shown in the very top left screenshot.

    The Sabre was interesting to fly, one of the key differences between aircraft of the fifties and modern jets being that the F-86 didn't have the tremendous reserves of power we take for granted now, so takeoffs were done with full flap after running the engine up against the brakes. Failure to do this can make a 6000 foot runway look really short. Initial climb is done in a shallow ascent, allowing the airspeed to build up from 120 to 300 knots, following which the climb angle can be increased, although not beyond 35 degrees. Speed brakes are used to slow down to 230 knots on approach, with long final entered at 200 knots and touchdown at 125 - 145 depending on weight. The flight model is very reasonable, although Kirk's skills really lie in making FS planes look real. You get both a 2D panel and a VC, to which the same comments apply, although the 2D panel includes some extremely good quarter and side views, rather than relying on VC screengrabs as many commercial developers seem to feel is sufficient.

    The sound set is aliased to the Lear and Kirk tells us in the readme that he uses an F-16 freeware set by Christoffer Petersen. I notice we have an FS2002 sound set for the Sabre done by Aaron Swindle which might be worth a try.

    Verdict? Compulsory download, I am afraid - and all the more extraordinary because this addon is the work of a single individual. Just explain to your significant other, parent, or favorite pet that you are going to be busy for a while. And give Kirk your vote in the monthly contest, because if anyone deserves a Developer's Award, he does.

    Andrew Herd
    andy@flightsim.com

    Download here