In 1949 the Swedish Air Force asked for something that did not exist anywhere in the world: an interceptor capable of Mach 1.4 to 1.5, able to operate from dispersed road bases, to meet a Soviet bomber threat crossing the Baltic.

Saab’s answer was a wing nobody had ever flown. Erik Bratt’s double delta had an inner section swept at 80 degrees and an outer panel at 57. For comparison, the wing on Saab’s own J 29 Tunnan was swept 25 degrees.

The wind tunnel could not settle whether it would work. So Saab built a small one and put a man in it.

Before the aeroplane, a model on a string

The 210 was not the first attempt. Saab’s aerodynamicists, working partly under the German aerodynamicist Hermann Behrbohm, began with a pulsejet-powered double-delta model flown on a tether, whirling in a circle while cameras recorded it. Small scale models were flown before that.

The results were suggestive and inconclusive. A model on a wire cannot tell you what an aircraft will do on approach with a pilot trying to land it, and low-speed handling was precisely the unknown. A double delta with that much sweep was expected to behave strangely at high angles of attack, which is where landings happen.

Built cheap, deliberately

Nothing about the 210 was precious. It existed to answer one question as quickly and cheaply as possible.

Parts of the internal structure were plywood. Instrumentation was pulled off a J 29 Tunnan. The landing gear came from a J 21R. The engine was a single Armstrong Siddeley Adder of roughly 1,050 pounds of thrust, which is a modest figure for a jet aircraft carrying a person.

One Swedish account describes it as the smallest aircraft ever fitted with an ejection seat, which is a single-source claim but a plausible one given the dimensions.

The nose was painted black, and for a practical reason: Saab’s theodolites had to track the aircraft along the flight-test corridors at Kolmården, and a black nose against the sky was easier to follow.

21 January 1952

Bengt Olow, who had run Saab’s flight test department since 1950, took the 210 off from the company field at Linköping on 21 January 1952 and flew it for about half an hour. Every source agrees on the date, which in a story with this many contested numbers is worth noting.

The wing worked. In the words of the Swedish technical press, the 210 essentially verified the wind-tunnel results and the calculations that had been made for the design. Two months after that first flight, the Air Force placed its first order for what would become the Saab 35.

The Swedish Air Force Museum, which owns the aircraft, tells its story above.

The two things it actually fixed

A testbed that only confirms what you already believed is a waste of money. The 210 earned its cost by finding problems.

The first was visibility. In its original 210A form the intakes sat at the nose and wing roots, and in the landing attitude they blocked the pilot’s forward view, which for an aircraft intended to operate from stretches of public road was unacceptable. Saab rebuilt it as the 210B with the intakes moved aft alongside the cockpit. Look at any Draken and you will see intakes beside the cockpit; that is the 210 talking.

The second was stopping. A drag chute was added in spring 1952 and subsequently adopted on every full-scale Draken variant.

Both fixes are small. Both would have been considerably more expensive to discover on a full-size supersonic prototype, and one of them would have been discovered by a pilot who could not see the runway.

What it became

The Draken first flew on 25 October 1955, again with Olow at the controls. It went on to Mach 2 in January 1960 and remained in service for decades, with production totalling somewhere around 612 to 615 aircraft depending on whose count you accept.

Bratt was almost ninety when he said that, and the aircraft he had designed was still flying.

The double delta never became entirely docile, mind. A former Draken pilot describes the handling in terms that explain why the 210 was built in the first place.

The aircraft that is still there

The 210 flew somewhere around 900 sorties over four years. The exact figure is disputed, with counts ranging from 887 to about a thousand, and the retirement date is given variously as 1955 or 1956. The commonly cited last flight of 25 October 1955 is worth treating with caution, since that is also the date of the Draken’s own maiden flight and a conflation is easy to imagine.

It sits today at Flygvapenmuseum near Linköping, in its 210B form. The red paint it currently wears is wrong, applied by a local workshop after a loading accident at a ground exhibition, without reference to the original colours. The museum has said it intends to restore the black scheme.

There is something fitting about the survivor of this particular story being the small one. Saab needed to know whether a wing shape could be landed by a human being, and rather than model it, argue about it, or risk a full-size prototype, they built a cheap little aeroplane with plywood inside it and borrowed landing gear, and went and found out.

The answer was yes, with two corrections. Both corrections went into every Draken ever built.

Sources: Flygvapenmuseum; Saab AB press releases, 1955 and 2005; Lennart Berns, Teknikhistoria (Ny Teknik), December 2023; Arboga Elektronikhistoriska Förening; Svensk Flyghistorisk Förening; Populär Historia; avionslegendaires.