1:72 Saab J27A - Sweden's last piston engine fighter design

Dizzyfugu · July 27, 2016, 11:41:18 PM

Is it a Spitfire? No! Is it a P-51 Mustang? No!

It's the the 'Blå Rudolf', a Swedish Saab J27A from F9!!!

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

Some background:
At the end of WW2, Sweden was in search of a new fighter offering better performance than the J21 could offer. The latter was an indigenous fighter/attack aircraft from SAAB that first took to the air in 1943 and dated back to a requirement from 1941. The J21 was designed as an unusual twin boom pusher configuration, where the propeller was mounted in the rear of the fuselage, pushing the aircraft forward. The advantages of a pusher design were that the view forward was unobstructed and armament could be concentrated in the nose, while the heavy engine was placed close to the center of gravity for better handling and agility. A major drawback was the difficulty in escaping from the aircraft in an emergency, though, as the pilot could get drawn into the propeller blades. SAAB deliberated between systems that would eject the pilot, or jettison the propeller or even the whole engine, via a system of explosive bolts, and eventually installed an early, explosives-powered ejector seat developed by Bofors for this purpose.
However, the SAAB 21 had its share of trouble (overheating an unreliable DB 605 engine), and in 1944 a new requirement for a more powerful and conventional fighter was issued. Selecting the Rolls Royce Griffon as the powerplant, SAAB initially looked into adapting the engine to the J21. However, this proved impractical, so SAAB started work on a clean-sheet design.

>1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

The L27, as it was known in the project stage, ended up closely resembling the latest designs to come from Britain like the Supermarine Spitfire or the Martin Baker MB 5, as well as the North American P-51 Mustang. The Griffon engine, chosen for initial development and flight tests, drove a contra-rotating propeller and sat in the nose. Top speed with the Griffon was expected to be around 700 km/h (435 mph). Later production aircraft were to be powered by a domestically developed, new H-24 cylinder motor similar to the British Napier Sabre engine and delivering output in significant excess of 2.200 hp (1.640 kW). With this machine, the aircraft was expected to reach a top speed of 740 km/h (460 mph) or even more.

The wings were similar to those used on the Fairey Firefly, complete with Fairey's characteristic Youngman flaps, but with small wing root extensions and a thicker profile than the late Spitfires' wings, and with more rounded wing tips. Similar to the P-51, the L27's landing gear with a wide track retracted inwards into the wings, and the tail wheel could be fully retracted, too.
Armament, consisting of four 20mm Hispano cannons, was to be concentrated in the wings just outside of the propeller arc, and unlike the Spitfire's arrangement with underwing coolers, the L27's single radiator was placed in a ventral tunnel position, very similar to the arrangement on the P-51.

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

A total of three prototypes were ordered, and the aircraft was now formally designated J27A; two were to be powered by Rolls-Royce Griffon 83 engines, and one as a test structure and earmarked for the development of the 24 cylinder engine and its integration into the projected J27B.
The first flight of a J27A took place in March 1945, and the promising results kept the project evolving until late 1946, when the aircraft was cleared for service and production in January 1947. 70 aircraft with Griffon engines were ordered.

Anyway, in early 1945, SAAB had also launched a project to determine how to provide the J21A with a jet engine to get the experience of jet engines and flying at high speeds. The goal was to catch up with the development of jet aircraft, which were moving ahead fast in England, where, among others, de Havilland already had the de Havilland Vampire in production. The resulting J21R, SAAB's first jet, made its first flight on 10 March 1947 and it marked the death knell for any piston-engine fighter development and use in Sweden. Consequentially the 24 cylinder engine never made it from the drawing board, and after the initial production run of the Griffon-powered J27A was completed until early 1949, further production was stopped and the whole J27 program terminated. Serial production J27As differed only slightly from the prototypes. The most obvious change was a taller vertical stabilizer and a small fin fillet, less obvious was a modified landing gear cover arrangement, because the original design with a single, large cover of the main wheels tended to bulge outward at high speed. A split design mended this problem.

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

While the J27A's projected top speed of 700km/h was impressive for a piston-engine fighter and frequently confirmed in service, it was inadequate in the oncoming jet age. In the end, SAAB opted to pursuit jet fighter endeavors that soon led to the very modern and innovative SAAB J29 that soon became Sweden's standard jet fighter.
In frontline service the J27 was, even though it was popular among its pilots and maintenance crews, almost immediately replaced by jets, at first with the J28B Vampire (from 1951 on), which were in turn quickly replaced in 1952 with the indigenous J29 Tunnan.

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

The last J27A was, after serving with fighter units primarily in southern Sweden, already retired from frontline duties in 1955. Some aircraft, though, were kept in service as target tugs, liaison aircraft for the air staff and for dissimilar air combat training. The last machine was finally decommissioned in summer 1961.

General characteristics:
Crew: One
Length: 9.90 m (32 ft 5 in)
Wingspan: 11.84 m (38 ft 9 1/2 in)
Height: 4.19 (13 ft 9 in)
Wing area: 22.2 m² (238.87 ft²)
Empty weight: 3,250 kg (7,165 lb)
Loaded weight: 4,150 kg (9,149 lb)
Max. take-off weight: 4,413 kg (9,730 lb)

Powerplant:
1× license-built Rolls-Royce Griffon 83 liquid-cooled V-12 engine, 2,340 hp (1,745 kW),
driving a six-bladed contraprop

Performance:
Maximum speed: 435 mph (700 km/h) at 20,000 ft (6,100 m)
Cruise speed: 495 km/h (265 knots, 308 mph)
Range: 1,100 mi (1,770 km)
Service ceiling: 40,000 ft (12,190 m)
Rate of climb: 3,800 ft/min (19.3 m/s)

Armament:
4× 20 mm Bofors cannon (license-built Hispano Mk.II cannon) with 200 rpg in the outer wings
Underwing hardpoints for 8-12 × 3inch "60 lb" rocket projectiles
or 2× 1,000 lb (450 kg) bombs
or a pair of 45 gal (205 l) or 90 gal (409 l) drop tanks.

The kit and its assembly:
This is a "real" what-if model, or at least the attempt to build a phantom aircraft from single parts! The SAAB 27 is a bit of a mystery, because valid information is sparse, especially concerning details about its shape. You find some drawings or profiles, but IMHO these are based on guesswork and rather vague. The J27 is frequently described as a "Swedish Spitfire with a P-51 radiator" or a "Swedish Super-Spitfire", but that leaves much to be desired, because the similarity is only superficial. Hence, this model here is rather a free interpretation of what a service J27 could have looked like.

Here's some reference material - not the subtle differences between all of them, despite the similar outlines:

Some SAAB L/J27 illustrations by dizzyfugu, on Flickr

For long time I fought with two building options: either convert a Fairey Firefly (Airfix' Mk. 5 would have been my bet), or use a Spitfire Mk. 22. After long considerations I settled for the latter one, because I feared that the Firefly would result in a rather massive aircraft, and the Airfix kit itself is vintage and worth a building fight on its own.

So I used an Airfix Spitfire Mk. 22, but from this (very nice!) kit just a few things were taken, because I wanted a more individual look. Only the fuselage, cockpit interior and landing gear survived, and I even inserted a 2.5mm wide "wedge plug" around the cockpit and wedge-shaped inserts at the fuselage halves' seams in order to add some beef to the sleek (if not spindly) Spitfire. I think it's hard to notice, but the overall proportions look good. At the tail and the front end, the original fuselage width was kept, though.

Reason behind this was the P-51 radiator's width (leftover from a Matchbox kit) that was considerably wider than the Spitfire fuselage. Furthermore, the thicker/more massive wings from a P-47 (from an early MPM kit) also called for a more massive body.

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) - WiP by dizzyfugu, on Flickr

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) - WiP by dizzyfugu, on Flickr

For the new wings, some adaptations to the Spitfire wing roots had to be made, though, e.g. a bulged mid-wing section under the fuselage. The Thunderbolt parts also had the benefit of wells for a landing gear that retracts inwards. I also used P-47 landing gear parts, even though the struts were shortened at their bases by 3mm and the covers accordingly. For the sake of a different look (the Spitfire wheels are very characteristic) I used different main wheels from a Revell G.91R. The landing gear cover arrangement differs from J27 sketches (as far as I can tell, it must have been similar to the P-51's), but I stuck with the P-47 parts because they match well with the rest of the aircraft.

The contraprop belongs to a late mark Seafire, left over from a Special Hobby kit. The propeller was in so far modified that I added a metal axis and a styrene tube adapter for the fuselage, so that both propeller parts can (theoretically) spin. OOB, the Special Hobby solution is simply to be glued onto the nose, fixed, despite being constructed in two separate parts?

Furthermore, the carburetor intake was changed: the Spitfire's scoop at the wings' leading edge was replace by a Firefly-style lip intake right behind the propeller.

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) - WiP by dizzyfugu, on Flickr

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) - WiP by dizzyfugu, on Flickr

The whole tail section was reconditioned, too. Descriptions of the J27's tail are corny, but "more square than a Spitfire's". Instead of simple cosmetic surgery I thoroughly replaced the OOB fin with a Supermarine Attacker's (Novo kit) with some mods to the outline, which fits well in size and is ...more square!

The new tail is a bit taller and has a fin fillet, making it look very P-51-ish, but that's O.K. for me. At least it's different from the round Spitfire shape.
I also exchanged the stabilizers, the round Spitfire parts gave way to differently shaped pieces from a Hobby Boss La-7. Their shape is similar to a P-47's, but they are smaller and match J27 illustrations well.

The canopy was also changed. Through the widened fuselage around the cockpit the tight OOB Spitfire hood would hardly match, anyway. The bubble layout remained, and I adapted a bigger Matchbox P-51 canopy to the new fuselage contours, and moved forward as far as possible.

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) - WiP by dizzyfugu, on Flickr

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) - WiP by dizzyfugu, on Flickr

Painting and markings:
The Swedish Air Force as operator was settled, as well as early post-WWII markings. But I did not want the standard, uniform olive green/blue grey livery, so I painted the upper surfaces with camouflage scheme made from two green tones: a medium green tone (Humbrol 102, Army Green, ~FS 34096) and a bluish, dark green (Humbrol 91, RLM 70 equivalent), applied in bands – somewhat inspired by a scheme carried by some SAAB 32 Lansen in the early 60ies.

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) - WiP by dizzyfugu, on Flickr

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) - WiP by dizzyfugu, on Flickr

The underside was kept in the typical Swedish blue-grey, for which I used Humbrol 87. The waterline was placed very low so that the upper camouflage was also taken to the radiator flanks under the fuselage and wings. The cockpit was painted in very dark grey (Humbrol 32), while the landing gear and the wells were kept in Aluminum (Humbrol 56).

As a 2nd squadron machine, the code letter became blue, as well as the two-part spinner, latter's paint was mixed, based on the squadron code letter decal's tone on the tail.
The roundels and the 'R' codes come from an RBD Studio aftermarket sheet from Sweden, further decals like the yellow '9' code, the squadron's 'Bonzo' dog mascot emblem as well as most stencils come from a Heller SAAB 21.

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

1:72 SAAB J27A; 'Blå Rudolf' ('Blue R', s/n 27044), Swedish Air Force Göta Flygflöttilj 9/2nd squadron; Säve airfield (south-western Sweden), summer 1949 (Whif/Kitbashing) by dizzyfugu, on Flickr

A complex build, yet the model aircraft looks so innocent... Anyway, the goal was IMHO achieved: this J27 model just looks like a "Swedish Spitfire with a P-51 radiator", and at first glance you cannot be certain if this is a modified Griffon Spitfire or a P-51D. Both is true, to a certain degree, but also not correct, because the changes are more fundamental and the wings are completely different from either. So, the mission's been accomplished.

The finish is a bit rough, but that's the price to pay for mating parts that were never meant to be put together. And I feel inclined to tackle a J23, too, a Bf109/P-51B design hybrid that was designed as a conservative alternative to the pusher J21.

TomZ · July 28, 2016, 02:05:30 AM

Oh yes!!!!!!!
This is absolutely fabulous

TomZ

Knightflyer · July 28, 2016, 02:13:29 AM

Love It!

I saw the photos on your website last night whilst idly browsing, and it's great to see the story behind the aircraft and the kit build

To agree with what you say ...at first glance, is it sort-of a Spitfire? is it sort of a Mustang? no it's sort-of (but neither!) both! Well done Sir, a brilliant build as always

loupgarou · July 28, 2016, 03:00:55 AM

Very interesting and "historical" whif. Well done!

zenrat · July 28, 2016, 03:50:42 AM

Very nice - both the build and the words.
Shouldn't Rudolf have a red spinner though?

When I looked at the drawing my first thought was Airfix Yak 9 wings.

PR19_Kit · July 28, 2016, 05:32:01 AM

What a splendid device, LOVE that prop!

NARSES2 · July 28, 2016, 06:20:48 AM

Superb build. Must admit there is something about contra-props which just screams "Power"

su27rules · July 28, 2016, 07:16:54 AM

Captain Canada · July 28, 2016, 03:31:21 PM

Great stuff Dizzy ! What an interesting mash up of parts. Love the colour scheme as well.

Dizzyfugu · July 28, 2016, 11:34:56 PM

Thank you very much, gentlemen.

Tophe · July 28, 2016, 11:45:37 PM

Wonderful!

Amphion · July 29, 2016, 03:37:58 AM

Well done, sir!

DogfighterZen · July 29, 2016, 06:07:55 AM

Very good, as always!

The two tones of green make a very nice camo, and the Swedish markings fit it like a glove.
The story's a good read too!

Dizzyfugu · July 29, 2016, 06:49:59 AM

Again, thanks a lot.

Currently checking the kit pile - I like the J27 a lot, and building a J23 sister ship (the conservative alternative to the J21 pisher) is tempting...

SPINNERS · July 29, 2016, 01:08:06 PM

Top drawer whiffing! Great work Dizzy.