The Gripen – an all-rounder

As previously mentioned, Saab had presented a proposal for a new multi-role aircraft as an alternative to the foreign aircraft that were being studied for the Swedish Defence department in December 1979. This was basically the same concept that FMV, the Defence Material Administration, had proposed several years earlier. The new aircraft would be smaller than the Viggen, but have similar or better performance. The new aircraft would also be cheaper than the Viggen!

The Swedish Air Force Commander-in-Chief now received a new directive to investigate both indigent and foreign multi-role aircraft alternatives. A problem that arose was uncertainty as to how the economic responsibility should shared, where the state thought that industry should bear the largest part of the costs of the development of a new aircraft. How much responsibility should the Defence Material Administration (FMV) take in respect of Saab, and how would the project be managed?

There was much debate between 1980 and 1982. A consortium, the industrial group IG-JAS was formed to manage the project. FMV saw with some concern the trust that IG-JAS had that new technology would make it possible to produce a smaller, better and cheaper aircraft compared to the Viggen and foreign alternatives. FMV had itself during the 1970s brought up the possibility, with the aid of technological improvements, to a smaller aircraft that could take over after the Viggen, but not to the level of ambition proposed by Saab.

For Saab it was also a matter of maintaining its presence as a manufacturer of modern combat aircraft in the future, too. Saab needed the JAS. To bring about co-operation with foreign manufacturers was something that was seen as necessary, but there were none that initially wanted partnership. However the engines would, as before, be manufactured under licence by Volvo Aero and the ejection seats and wings bought from British Aerospace (BAe). Later BAe would become a partner, but at the beginning of the 1980s this had not come about.

Saab decided to continue with the canard wings, as in the Viggen, in front of a delta wing. However the canard on the Viggen was fixed, whereas that on the new aircraft would be movable. All three tasks, Interception, Ground Attack and Reconnaissance, could be carried out by one and the same aircraft. This led to the Swedish abbreviation JAS that became almost a nickname for the aircraft. Reconnaissance cameras would for example be carried in pods hung below the aircraft as necessary. This meant that there was no need for a special version with built-in cameras.

The Swedish Parliament approved the JAS 39 project in May 1982. A year later the project was approved by the Parliament once more. The ball was now rolling and the journey had seriously begun. Saab invested a great amount in technical development that was either budding or predicted. Promising that the aircraft would be smaller, more efficient and cheaper than the Viggen were lofty goals. A competition was announced to name the new aircraft, and the winning alternative was “Gripen” (Griffin in English). A griffin is a mythical animal made up of two or more different animals, most often the forebody of an eagle and the rear part of a lion.

The Gripen (Griffin) is a legendary creature with long historical roots. Illustration from the 1660s.

New solutions

Saab focused on a design with a moveable canard wing on the nose in combination with a delta main wing. The company had a lot of experience with delta wings and canards but not with movable canard wings. This combination was seen as the best compromise that among other things would provide good manoeuvring characteristics at both subsonic and supersonic speeds. A computer-based control system to assist the pilot would be required to assist the pilot in managing the movable nose wing,

Now in retrospect one could say that Saab truly led the way within aviation development, in such a way that could be described, paraphrasing a line from the science fiction series Star Trek “To boldly go where no one has gone before!” The target was set very high, and the aim after all was to build an aircraft that could carry out everything the different versions of the Viggen could do but even better. This required the development of technology and software that did not so far exist and that also had to be both robust and reliable.

One aspect that the flight control system would need to take care of was to prevent the pilot making sudden control inputs that would result in high G forces. A human can cope with up to 9G, i.e. 9 times the normal gravitation force. Regardless of the pilot’s input the system must prevent the aircraft from being exposed to manoeuvres generating more that the defined 9G.

Hence the level of innovation in the project was high. However the aim was also to design an aircraft that could be effective for forthcoming decades, during which each individual aircraft, by the exchange of the equipment it carries, would be able to perform interception, ground attack and reconnaissance missions. Thus instead of differently designed aircraft, every individual aircraft would be able to act as the ultimate multi-role machine. In 1982 there did not exist any aircraft with this capability. But Saab was not afraid to try. Perhaps it was sensed that this was make or break for Saab’s future as a manufacturer of advanced combat aircraft, or even as an aircraft manufacturer at all.

In hindsight one could see that the costs became higher than had been hoped, but it cannot be said that the Gripen turned out to be more expensive than the Viggen, so the expectations were met, if at least partly. On December 9th 1988 it was at last time for the first flight. The first prototype, designated as 39-1, performed a successful first flight, so that a major step had been taken. 

Disaster strikes

However the project unfortunately took a serious hit within the following 3 months. On February 2nd 1989 Saab test pilot Lars Rådeström was coming in to land from its sixth flight when the aircraft began to swing violently from side to side. Lars Rådeström tried to abandon the landing and save both himself and the aircraft by lighting the afterburner to get more power and climb away ready to attempt another landing. But he had no more time than to switch on the afterburner when the aircraft rolled and one wing hit the ground. The aircraft rolled over, both wings broke off and the fuselage continued rolling with added power due to the afterburner being lit. Everything was filmed and the film shown on the TV news.

Rådeström had no chance to leave the aircraft and save himself. Also there was a cameraman standing next to the runway who missed death by inches. For bystanders it seemed that the catastrophe had claimed at least one human life and maybe two.

There were however despite the accident two saving graces. The cameraman was unhurt and by what was almost a miracle Lars Rådeström also survived the crash, even though he had a broken arm. He was saved by the cockpit’s robust structure as it protected him while the aircraft rolled over and over on the ground. On that point, the aircraft lived up to expectations. But what had caused the violet swinging from side to side? Investigations showed that the flight control system and the pilot had come to oppose each other. The control system was not programmed to halt a manoeuvre if the pilot made a rapid alteration. When Rådeström hastily made such an alteration the flight control system rapidly swung the rudder from side to side. So when Rådeström corrected his first manoeuvre the control system made a full power change to one side, followed by a similar move to the other side. This caused the large swings to left and right, causing the aircraft to roll uncontrolled and strike the ground.

This event illustrates how ground-breaking the JAS flight control system was. The fact that the prototype crashed at such an early testing stage was considered by some as a sign that this was a bad aircraft.

The truth is however that more or less all aircraft have crashed at least once while at the prototype stage. This is even more common when it comes to the development of advanced combat aircraft that must be at the cutting edge of what is technically possible in order to have an advantage over their competitors in future air warfare. It is really only in the last few decades that accidents involving prototypes can be counted on the fingers of one hand. But due to the enormous costs that result from development of combat aircraft, even the slightest mishap is a sensitive matter.

Jas 39 Gripen

39-2 in its previous location at the Swedish Air Force Museum. This is now the oldest JAS aircraft and is currently housed in the Aeroseum. Photograph: Rikard Kalm, Swedish Air Force Museum.

The project continued, and after full use had been made of this experience, the second prototype 39-2 appeared. This is the aircraft that is now on display in the Aeroseum. Test flying could successfully resume and in 1992 the Swedish Parliament ordered 110 aircraft from Saab to equip the Swedish Air Force. This took place against the end of the Cold War and the start of a reduction in Swedish armed forces. However the JAS 39 Gripen was an important project, and even though not as many aircraft were ordered as originally expected, the affair began. A and B versions were also just a start. A modern combat aircraft has to be designed so that it can be upgraded several times in order to keep pace with developments. It is no longer a question of years of life, but decades.

Lightning never strikes twice in the same place… or does it?

When the decision on the JAS project was taken in 1982 the FMV ordered 5 prototypes and 30 production aircraft. 10 years later in 1992 a second batch was ordered, comprising 96 aircraft, to be called the JAS 39 Gripen A. 14 of these were built as a two-seat version for pilot training and called the JAS 39B. However before all these aircraft had been delivered, two newer versions, the JAS 39 C and D appeared, being the last 20 on the line. By 1993 the Swedish Air Force had received the first production aircraft, although they had not so far been issued to operational units. It would still take a little time before the JAS 39 Gripen could be considered an operational part of the Air Force. Production aircraft bore the serial number starting with 100, i.e. the first was assigned the 39-101, the next 39-102 and so on. This was the difference between the prototypes and production aircraft.

However although none of the aircraft played an active part in the Air Force, it was decided that one example should participate in the Stockholm Water Festival, a major public event that was held in the Swedish capital city each year between 1991 and 1999. So it was that on August 8th aircraft 39-102 took off to perform an air display over the city. Despite the aircraft now belonging to the Air Force, it was Saab’s test pilot Lars Rådeström who flew it. This was not so strange, since Lars now had over 100 hours flight time on the type, with several having been displays. But the flight control system was still being tested and there were limits to certain manoeuvres. The person who made the decisions on the display was the head of the Air Force and the aim was not to demonstrate the maximum performance, partly for technical reasons but also not to reveal everything to foreign observers.

What happed is described in detail (although in Swedish) elsewhere, such as in the book “JAS 39 Gripen” by Gunnar Lindqvist and Bo Widfeldt. For anyone who is not really familiar with the technology, it may be confusing, but here follows a simplified description of what happened.

After showing off a number of rolling and swooping manoeuvres, the aircraft’s nose reached a relatively high angle of attack in relation to its forward motion. That is to say that the nose pointed upwards. While landing, most aircraft approach at a certain angle of attack in order to touch down with the main wheels first, before the nose wheel. Before this particular Gripen flight, the governing FMV-Prov, had stated that the greatest permitted angle of attack would be 20 degrees. But now the aircraft had an angle of attack of 21.7 degrees, thus exceeding the limit, so the pilot tried to quickly correct this by rolling the aircraft to get it back to level flight.

He succeeded and the angle reduced, but while he was trying to get back to level flight the aircraft continued to roll beyond and despite Lars giving full rudder to correct, the aircraft continued to roll. There followed a series of movements with the aircraft tipping and rolling, resulting eventually in the nose pointing down and the aircraft leaning over 35 degrees to the right in relation to the direction of movement. In a final attempt to regain control of the aircraft the pilot pulled on the control column in order to bring the nose up and level out, but instead it stalled and ended up with the nose pointing high up while flying very slowly. This was fatal situation for the aircraft. If an aircraft flies too slowly it loses lift, or stalls, as it is called. In this case the height above ground and water was relatively low, a little above 300 metres, so there was virtually no chance of saving the situation. Added to this was the fact that the aircraft was not responding as expected to the attempts to rectify the situation, and all was lost. For Lars Rådeström there only remained an attempt to save himself, so he ejected and came down under a parachute. The aircraft continued to stall and in front of thousands of terrified spectators crashed to the ground on the small island of Långholmen, in the centre of the city.

Everything has a price

This could well have been disastrous, with many deaths. We shall never know what went through Lars’ head as he swung under the parachute on the way down to the water. In an interview he gave in 2002 he said that he felt no guilt about what happened. But he added that this was probably due to what must be seen as yet another miracle. Despite the violent crash and the subsequent firestorm, only one spectator was injured, a woman who suffered burns. There were no fatalities and no other physical injuries.

Thanks to fact that the technical equipment that recorded the flight survived, and that so many spectators filmed the events from many different angles, the investigators had an excellent picture of what exactly had happened. It turned out that within that particular speed range the flight control system became unbalanced. Resulting from the pilot’s commands, the rudder’s actual limits and the control column’s characteristics there began what is called Pilot Induced Oscillation (PIO). Broadly speaking, this was a similar situation to that which occurred in the first accident. The aircraft did not respond as expected, due to the unbalanced control system when Lars tried to save the situation.

The whole episode led to a halt in Gripen flying for the following five months, but during that time a solution was successfully found to prevent the pilot and the flight control system opposing each other.

Nevertheless this was the end for Lars Rådeström. Test flying is extremely demanding work and is associated with a great deal of risk. Test pilots are flying in aircraft with characteristics that are not completely defined, so they are constantly flying into the unknown. Thus test pilots normally retire at the age of 50. Lars was 49, with only a short time left, so he decided to stop flying. He didn’t want to tempt fate more than he already had. He had cheated death twice by a hairsbreadth, and both times without killing an innocent. But how would it end the next time?