J 19 - Saab L-12 A Swedish "Zero"
What stopped this project was in fact the outbreak of the war, as the intended engine was to be a Bristol Taurus II, giving 1400 hp with 100-octane fuel. The British had to concentrate on known engines (and the Taurus would have been overweight and underpowered anyway), and as a replacement P&W Twin Wasp was considered (and well, the US didn't want to sell us any engines at that time). Also, Saab had to concentrate on B 17 and B 18, so there was never even a wind tunnel model built.
It looked very much like a Zero, and was an all-metal construction with fabric covered control surfaces. Span 10.5 m; Empty weight 2015 kg; Operational weight 2690 kg; Max speed 605 km/h; Engine 1065 hp Bristol Taurus; Armament four wing-mounted 13.2 mm guns and possibly two 8 mm MG:s on top of the engine.
J 23 - Saab L-23 A Swedish "Bf 109/Mustang"J 21 (which hardly was a fighter, but became a passable ground attack aircraft). This was a technological risk, with ejection seat and all, so a more conventional fall-back design with the same engine was needed. In December 1941 the fall-back design was cancelled, as it was considerably less manoueverable than the J 21. Both designs were to use the same engine, DB 603, and interestingly the J 23 was to have an ejection seat too!
In front of the wing trailing edge it was just like a Bf 109, except the canopy which looked like the J 21's and that the landing gear folded the other way. Rear of that it was just like a P-51B, but with a slimmer oil cooler.
Span 11.3 m; Empty weight 2535 kg; Operational weight 3445 kg; Max speed 626 km/h; Armament one 20 mm engine-mounted gun and four 13.2 mm wing mounted.
B/J 24 - Saab L-24 A Swedish "Bf 110"
Span 15.6 m; Armament as a bomber 1000 kg + four 8 mm MG:s and two 20 mm guns, as a fighter six 13.2 or 20 mm guns and a radar.
J 27 - Saab L-27 A Swedish "Super Spitfire"
Most of all, it looked like a Spitfire 22 or a Spiteful, but with a more squared fin and with the oil cooler under the after fuselage. The wings looked more like those of the Fairey Firefly, and like it had Youngman flaps (well, Youngman worked for Saab at the time). A butterfly tail was considered. Max speed would have been 700 km/h, which of course made it outdated in the jet age.
Sweden's nuclear bomber (that never was) or A 36, the 'missing' aircraft between 35 and 37
In the late 1940's work was started on getting Sweden nuclear weapons, which studies showed would be technically and economically feasible. In 1952 Saab started designing an aircraft with long range, large weapon load and high speed as 'Project 1300'.
It was equipped with a single seat, straight delta wing with 62 degrees sweepback, chin intake and internal weapon bay. (The latter _only_ because of concerns about accidental detonation due to the high temperatures air friction would cause.) Primary weapon would be a 600-800 kg free fall nuclear weapon.
Length: 17 m Span: 9,6 m Wing area: 54 square meters Empty weight: 9000 kg Max load: 1500 kg Fuel: 4000 kg Max take off weight: 15000 kg Engine: Bristol Olympus Thrust/weight ratio (take off): 0,73 Max speed: Mach 2,14 above 11 km; mach 1,2 at low altitude Radius of action: 410 km Ceiling: 18 km Take off run: 490 mThe project was cancelled in 1957 and all resources concentrated on Viggen. However, it wasn't until 1966 parliament finally decided Sweden wasn't going to get nuclear weapons.
A 38/Sk 38, another "missing" Swedish Air Force designation.
At the same time, a completely new advanced light attack/trainer (project 'B3LA') was to be developed, replacing the 1960's Sk 60/Saab 105. It was to have a very sophisticated avionics system, with a FLIR as main sensor, including automatic target recognition and multiple missile lock-on.
The 'A20' was cancelled, since it wouldn't be much cheaper to develop than a new aircraft, and just as expensive to operate as the 'old' Viggens. Instead development of a 'next generation' aircraft (=Gripen) was timed to an in-service date in the 1990's instead of 2000's, first replacing attack Viggens and then Fighters, instead of the other way round. (The first Fighter-Viggens won't be withdrawn till at least 2005, and some will certainly serve until after 2015.)
The B3LA was cancelled on cost grounds, instead a simplified trainer/attack version of it was suggested, and this got the designation A 38/Sk 38. It was cancelled as well, but sort of a 'B3LA' flies today as the Aeritalia-Aermacchi-Embraer AMX. (Saab cooperated with Aermacchi during the development.)
Note: This document was written in 1995; The predictions for how long Viggen would remain in service was far off, in fact the fighter Viggen was retired in 2004 and the last Viggen version, SK 37E, in 2005.