Accidents and incidents involving the JAS 39 Gripen

The JAS 39 Gripen is a 4.5 generation fighter aircraft manufactured by the Swedish aerospace company Saab.

This is a complete list of crashes as of June 2008. Apart from the other incidents documented, five Gripens have crashed, two of them before the delivery to the Swedish Air Force; one prototype, one production aircraft and three in service with the Swedish Air Force.

Crashes in the test series

February 1989

On 2 February 1989, the first prototype JAS 39-1 crashed on its sixth flight, when attempting to land in Linköping. The accident was filmed in a now famous recording by a crew from Sveriges Television's Aktuellt. [http://svt.se/svt/road/Classic/shared/mediacenter/index.jsp?d=37267&a=399477 News footage of the 1989 and 1993 crashes] , Sveriges Television sv icon. ] The pilot, Lars Rådeström, remained in the tumbling aircraft, and escaped miraculously with just a fractured elbow and a few other minor injuries. The crash was the result of pilot-induced oscillation (PIO). Extremely gusty winds were also a contributing factor. Lindqvist, Gunnar & Widfeldt, Bo, "Rikets flygplanköp - JAS 39 Gripen", Nässjö, Sweden: Air Historic Research AB, 2003, ISBN 91-973892-5-0, pp. 164-168 sv icon. ]

August 1993

On 8 August 1993, a production JAS 39A Gripen (serial no 39-102) crashed on the central Stockholm island of Långholmen, near the Västerbron bridge, when the aircraft stalled after a slow speed manoeuver during a display over the Stockholm Water Festival. The crash was, like the first one, caused by PIO, and caught on film. The pilot − Rådeström again − ejected from the aircraft, and landed safely by parachute, though he became stuck in a tree. The aircraft fell to the ground and caught fire on impact. Despite large crowds standing by watching, no one on the ground was seriously injured, and the fire was soon put out.

The aircraft had been delivered to the Swedish Defence Materiel Administration in June, only two months prior to the crash. The display flight was not classified as in-service, because it was being flown at a display by a test pilot, rather than a Swedish Air Force officer.

Crashes in service

The only in-service crashes so far have involved the Swedish Air Force.

wedish Air Force

eptember 1999

On 20 September 1999, a JAS 39A Gripen (serial no 39-156) from Airwing F 7 Såtenäs crashed into Lake Vänern during an air combat manoeuvering exercise. After passing through the wake vortex of the other aircraft, the aircraft abruptly changed course, and the pilot, Capt. Rickard Mattsson, got a highest-severity warning from the ground-collision warning system. He ejected from the aircraft, and landed safely by parachute in the lake, where his colleague observed him getting into the inflatable life raft. He was picked up by a rescue helicopter 27 minutes later.

The Swedish Accident Investigation Board (SHK) could not fully determine the cause of the crash until the crash protected memory was found some 15 months later. The preliminary report is available in English. [http://www.havkom.se/index-eng.html Statens haverikommission] , SHK (Swedish Accident Investigation Board). ]

SHK's final report – not available in English – concluded that the plane had passed through the other aircraft's wake vortex while in a steep (−70 degrees) dive. When passing, the pilot's pitch command was "up", but instead the vortex inflicted a large aerodynamic transient on the aircraft, throwing it "down" into an almost vertical (−85 degrees) dive. These factors combined to create an angle of attack that was too large for the command to be obeyed, and so the ground-collision warning system alerted the pilot that a turn to avoid a crash would require more than 10 "g". He then chose, in full accordance with the flight manual, to eject. At the same moment, however, the vortex effect ceased as suddenly as it had appeared, instantly reducing the angle of attack to within limits, and thus the plane was flyable again, and could in theory have been saved.

The flight status in the moment of ejection was: altitude 750 m, flight angle −75 degrees, speed 350 km/h, angle of attack −8 degrees, and load −1.5 "g". [ [http://www.havkom.se/virtupload/reports/rm2002_02.pdf "Rapport RM 2002:02"] , Swedish Accident Investigation Board sv icon. ]

June 2005

On 1 June 2005, a JAS 39A Gripen (serial no 39-184) from Airwing F 17 Kallinge, when acting as a target in a dogfight exercise, apparently ceased to obey commands from the pilot, LtCol Axel Nilsson. After attempting to regain control while the aircraft slowly descended, the pilot ejected from the aircraft and landed safely by parachute.

SHK's investigation — report published in June 2007 — showed that the aircraft initially travelled at Mach 0.6 in a shallow dive at an altitude of 5500 m. When attacked, the pilot, not fully aware of the rather low speed, tried to escape by taking the plane into a steep (60 degrees) climb. This led to a "low speed"-warning, for which the pilot tried to compensate by lighting the afterburner and manoeuvering into an offset looping, briefly applying maximum angle of attack. The intent was to regain speed at the top of the loop. However, the speed was too low, and the aircraft ended up in an inverted (upside-down) superstall, and started to descend slowly.

While there are measures to get out of this situation, those taken by the not-fully-trained pilot were either inadequate, insufficient or counter-productive, and he ultimately had to abandon the aircraft. [ [http://www.havkom.se/virtupload/news/rm2007_03.pdf "Rapport RM 2007:03"] , Swedish Accident Investigation Board sv icon. ]

April 2007

On 19 April 2007, a JAS 39C Gripen (serial no 39-259) from Airwing F 21 Luleå crashed at the Vidsel airfield in northern Sweden. [http://svt.se/svt/jsp/Crosslink.jsp?d=22620&a=810111 "Jas aircraft crashed in Norrbotten"] , Sveriges Television sv icon. ] The pilot, Stefan Kaarle, was involuntarily ejected out of the aircraft in mid-air while approaching the airstrip in order to land. He landed safely by parachute.

SHK's investigation confirmed initial suspicions that the ejection seat handle − placed between the pilot's thighs − had been activated by the motions of the pilot's flight suit. Repeated jerks on the handle, resulting from the G-suit inflating and deflating during the flight, had ultimately exerted enough force on it to cause an uncommanded ejection. Moments before the ejection, the pilot had taken the aircraft into a tight turn, thus causing the G-suit to activate.

For the C and D models of Gripen, the ejection seat handle had been moved and redesigned to make room for larger cockpit displays. The investigation showed that the new handle was prone to these kinds of uncommanded ejections. A survey among the airwings that fly the Gripen revealed that the handle on other Gripens had become dislodged before, though not far enough to cause an ejection. The investigation concluded that the quality assurance procedures between the Swedish Defence Material Administration, the Swedish Air Force and Saab were not adequate to discover the error in time and were therefore cited as the main reason for the accident. [ [http://www.havkom.se/virtupload/news/rm2008_01.pdf "Rapport RM 2008:01"] , Swedish Accident Investigation Board sv icon. ]

Other incidents

November 2004

On 17 November 2004, a Swedish Air Force Gripen had a birdstrike in the airspace south of Gotland. A seagull was sucked into the right air intake, and the pilot decided to make an emergency landing at Visby Airport.

October 2006

On 11 October 2006, a pilot from the Czech Air Force flying a Gripen almost hit a target-towing Learjet 35 in a live fire exercise at Vidsel airfield. When practicing using the on-board automatic cannon, the Czech pilots mistakenly targeted a reserve target close to the towing plane instead of the intended target 600 meters behind the Learjet. After several "dry runs", live firing commenced, and the first pilot fired on the reserve target. Several rounds hit it, and were calculated to have passed within 10 meters of the Learjet. After this the Czech pilots discovered the actual target they were supposed to fire on, and proceeded to attack it instead. The crew of the Learjet did not notice anything out of the ordinary besides hearing the sound of the cannon, without making the connection that they had been fired upon. The incident was discovered after landing.

SHK's investigation concluded that the causes of the incident were that too many activities were scheduled for too short a time span; that the safety regulations concerning live fire exercises were outdated; and that the assignment of responsibilities and duties of the Swedish Armed Forces, the Swedish Defence Material Administration, Saab Special Flight Operations and the Czech military units were unclear. These causes put together resulted in the Czech pilots not being fully aware of the true configuration of the Learjet and the targets, which in turn led to them targeting the wrong target and one of them eventually firing on it. Contributing causes were that the Czech pilots had little to no experience of this kind of exercise, and that the target towing Learjet had no means of monitoring the exercise. For instance the Learjet lacked a radar warning receiver that could have revealed that they had been targeted by the Gripens. [ [http://www.havkom.se/virtupload/reports/rm2007_04.pdf "Rapport RM 2007:04"] , Swedish Accident Investigation Board sv icon. ]

April 2007

On 10 April 2007, just nine days before one of the crashes mentioned above, a Swedish Air Force Gripen had a birdstrike in northern Sweden. The collision with the bird dented lower parts of the fuselage, and the pilot made an emergency landing at Luleå Airport/Kallax Airbase (combined public/military), after which he also made an emergency exit from the cockpit by removing the canopy with built-in explosives.

October 2007

On 3 October 2007, a Swedish Air Force Gripen almost collided with a passenger aircraft, [http://svt.se/svt/jsp/Crosslink.jsp?d=33731&a=950262 "Jas aircraft near collision with passenger aircraft"] , Sveriges Television sv icon. ] a Saab 340 from Avitrans Nordic on its way from Ronneby to Bromma, in the airspace south of Oskarshamn. The pilot on the passenger aircraft was alerted by the collision warning system that another aircraft was approaching at the same altitude. Preliminary data indicate that the aircraft may have been less than a nautical mile apart.

SHK classifies the incident as serious, and has initiated an investigation.

References

External links

* [http://www.havkom.se/index-eng.html Statens haverikommission (SHK), Swedish Accident Investigation Board]