By
1945, it was clear that in the future all Swedish combat aircraft
would be jet powered, so all propeller projects were cancelled.
STAL was already working on jet engines, but they wouldn't be
ready until 1952, which is to say too late for any aircraft project
started in 1945. As a quick fix de Havilland Vampires were purchased
in 1945 and licence production of its Goblin engine was started
for the jet engined variant of Saab's J 21 fighter. It was from
the outset clear that Goblin would be too small for the new "JxR"
fighter beeing planned, and in December 1945 the De Havilland
Ghost engine, still in the early stages of design, was selected
and chosen to for licence production in Sweden. The earliest
design work decided the relative merits of a "Vampire"
or "Shooting Star" configuration, but finally the choice
was to stand between project R 1001 "The Cigar" of
a "Shooting Star" layout and R 1001 "The Barrel".
December 1945 saw the latter as the victor, and it looked much
like the production items, but the tail was a little bit longer
and the wings had a shorter chord near the tips.
The very first "Barrel" concept in October 1945 had
straight wings, but in November Saab came into possesion of German
research material, via Switzerland (the same material that was
handed over to USA, but we got ours in a slightly less official
manner, and put it to use much earlier), which showed advantages
of swept back wings. The 45 degree sweep the Germans planned
was deemed to be too extreme from a standpoint of stability,
likewise it would affect the weight of the wing negatively, so
a 25 degree sweep back was selected, together with leading edge
slots. At first the fuselage was to have a continous curve like
a barrel, but it was found that it was better to have the centre
section of the fuselage cylindrical. This was area rule, a few
years before the name was coined. Saab 201 was a Saab 91 Safir
with a scaled down wing to prove that swept wings worked well,
first flew on April 28:th 1946. The first Saab 29 prototype first
flew on Sept 1:st 1948. It had full span flaperons, but later
prototypes and the production machines had separate flaps and
ailerons, not because it worked better, but rather that the customer
was more familiar with it and had required it on the second prototype.
The reasoning behind the flaperons was that since the ailerons
had to be powered anyway, and artificial feel introduced, combining
them with flaps wouldn't change the feel of the controls, and
would lower landing speed by 10 km/h.
At first when the reconnaissance version was designed, the Air
Staff had a very modest requirement for camera equipment, and
only minimal changes to the fighter was envisioned. Luckily,
a reconnaissance wing commander loaded a truck with everything
he thought would be needed, and together with the chief designer
and an axe, he proved that there was room for it in the wooden
mock up. "You're a good designer, you'll solve the details!"
The whole front lower fuselage was redesigned, with the bottom
beeing flat and the sides near vertical. Up to five cameras of
different types could be carried at the same time. To begin with,
only a pair of cameras salvaged from our Spitfire PR.XIXs were
used, without sights even. All camera ports were covered by shutters,
the forward ones opening down and forward, thus beeing usable
as air brakes as well. Later on camera sights were introduced.
The use of "camouflage detecting" IR colour film was
investigated, but found to be much too expensive (USD1000 per
roll was a lot of money then). What was done was to let the left
forward looking long focal length camera use black and white
IR film, the right panchromatic film. By comparing the pictures,
some anti-camouflage effect was attained. IR film also gave the
camera a longer useful range during conditions of haze.
A pair of S 29Cs set a world record for a 1000 km closed circuit
on March 23:rd 1955 with 900.6 km/h (the old record beeing 822
km/h taken by a RAF Gloster Meteor in 1950). Well done keeping
two aircraft together and still getting the fuel to stretch.
The external tanks were dropped at the point were they were estimated
beforehand to have run dry, as there was no separate meter for
them. S 29C was the first Swedish combat aircraft to be equipped
with radar warning recievers. All were rebuilt with -E wing during
1955-56, permitting maximum speed to be raised from Mach 0.86
to 0.93, but they never got afterburners.
15 A 29Fs were sold to Austria in 1961. The second batch of 15
was delivered in 1963-64. They were modified to let the left
two cannon be exchanged in 30 min for a set of three 70 mm Vinten
cameras in 30 minutes. There were two side facing camera ports,
two down facing and one down and forward. Twelve such camera
sets were delivered.
In spite of beeing purchased for their suitability for close
air support, neither rockets nor bombs were ever purchased for
them. Air interception was only a tertiary role, reconnaissance
a secondary.
A trainer version, SK 29, was planned in 1950, but it was cancelled
the same year. It was to have had side-by-side seating, no armament
and reduced fuel. Aft of the cockpit it would be identical to
the fighters.
Saab had a very tight delivery schedule for the fighters to the
air force, which made it impossible for them to also build the
required 20 trainers. The air force on the other hand, didn't
think it would be a good idea to modify the aircraft into trainers
themselves, which was suggested as a solution. Probably not a
good idea, as there were quite a few landing accidents.
A radar equipped all-weather version was also studied and cancelled
in 1950, for the same reasons as the trainer version. The favoured
installation consisted of a bulge over the air intake. Wavelength
were to be 3 cm with an effect of 100 kW. It was to have a spiral
scan pattern. These capacity problems later on led to Saab having
to cancel their Saab 90 Skandia airliner in favour of building
Tunnans for the air force.
As part of a UN operation, five J 29Bs were sent to Kongo in
1961. They were followed by two S 29Cs and four additional J
29Bs in 1962. The operation, the only one involving Swedish made
jet combat aircraft, ended in 1963.
Country: Sweden
Constructor: SAAB
Type: fighter
Crew: 1
Length: 10.23m
Height: 3.75m
Wing Span: 11.00m
Wing Area: 24.15m2
Max t-o weight: 8375kg
Engines: 1 SFA RM 2B (De Havilland Ghost) rated 2800kg
Max Speed: 1060km/h
Range: 1100km
Armament: 4 20mm guns with 180 rnds each, AIM-9 Sidewinder, rockets,
napalm bombs, bombs, rockets and droptanks
