Accidents and incidents involving the JAS 39 Gripen
On 20 September 1999, a JAS 39A Gripen (serial no 39-156[2]) from Skaraborg Wing (F 7) crashed into Lake Vänern during a dogfight exercise.
The Swedish Accident Investigation Board (SHK) could not fully determine the cause of the crash until the black box was found some 15 months later.
The pilot never realized that the plane had entered a stall and only noted that his pitch inputs had no effect, so when he saw the ground collision warning he elected to vacate the aircraft in accordance with the flight manual.
The period when the angle of attack was above 20° lasted 3.2 seconds; coincidentally the airplane returned to a controllable condition almost exactly when the pilot released the stick to pull the ejection seat handle.
The report considers a few different hypotheses, for example the high angle of attack could have caused the altimeter to measure an incorrect value, leading to a miscalculation of the sink rate.
The flight status at 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. 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, Lieutenant colonel Axel Nilsson.
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 speed was too low, and the aircraft ended up in an inverted (upside-down) deep stall, and started to descend slowly.
[10] On 19 April 2007, a JAS 39C Gripen (serial no 39-259) from Norrbotten Wing (F 21) crashed at the Vidsel airfield in northern Sweden.
[11] The pilot, Captain Stefan Kaarle, was involuntarily ejected out of the aircraft in mid-air while approaching the airstrip in order to land.
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 the ejection.
For the C and D models of Gripen, the ejection seat handle had been moved and redesigned to make room for larger cockpit displays.
Both crewmen (Brigadier general Csaba Ugrik and Major Gergely Grof) ejected safely with no injuries.
[14][15] On 14 January 2017, a Gripen crashed during an air show for the Children's Day in Hat Yai, Songkhla province, Thailand.
Squadron leader Dilokrit Pattavee was killed when the aircraft crashed on a runway at Wing 56 during the air show at around 9.20 am.
The ground proximity warning system activated 8 seconds before touchdown, but the pilot disregarded it because it was known to sometimes give false alarms.
The aircraft gained considerable speed before rolling off the hard surface and onto nearby soft terrain, where it then flipped over.
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 in northern Sweden.
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.
