Mid Air Collision Typhoon & Learjet 35
During ‘Renegade’ air interception training a civilian Learjet 35, D-CGFI, collided with a Luftwaffe Eurofighter Typhoon. The German Federal Bureau of Aircraft Accidents Investigation (BFU) have issued their final report and we attended an excellent briefing by the BFU at the ISASI 2015 conference. In Germany, as in the UK, air accidents involving both civil and military aircraft are investigated by the civilian accident investigation body.
The mid-air collision occurred on 23 June 2014, over Olsberg, North Rhine-Westphalia. The civilian aircraft crashed and both crew members died. The damaged Typhoon performed an emergency landing at Nörvenich Air Base.
The Learjet was operated by GFD, a German defence contractor that provides target towing and other training services. The company, founded in 1966, operated 13 civil registered Learjets for military training support. They gained a German Air Operators Certificate (AOC) in 1989, but that AOC covered passenger and cargo operations (commercial air transport), not their actual training support activity (aerial work).
The Learjet and two Typhoons were involved in an ‘Renegade’ interception exercise (with the Learjet simulating a potentially uncooperative airliner) when the collision occurred between the Learjet and the lead Typhoon.
The collision occurred shortly after the intercepted target began to comply with the instructions given (as part of the exercise it initially ‘failed’ to obey).
The Learjet Captain was Pilot Monitoring and the Co-Pilot, Pilot Flying. Both were ex Luftwaffe fighter pilots. The Captain was using a portable computer, effectively an unapproved Type B Electronic Flight Bag, for navigation purposes throughout the flight.
Having started to ‘obey’ the intercepting fighters commands, about 15 seconds prior to the collision the autopilot was disengaged and the Co-Pilot flew the airplane manually to follow the Typhoon into a left-hand turn. The BFU concluded the slant range of the two aircraft was initially approximately 30 m. The turn continued, but the Co-Pilot was unable to maintain visual contact with fighter once the Learjet reached a 4° bank angle. The Learjet was turning more sharply than the fighter and was accelerating. Control was passed to the Learjet Captain but at this critical moment he had to pass the laptop to the Co-Pilot. The two aircraft came into contract, 2 seconds later, with the Learjet being catastrophically damaged.
The BFU say:
The operator’s safety management had not sufficiently analysed the use of the computer, and the cross cockpit procedure in regard to flight safety risks.
The company had issued an Safety Management Handbook on 1 June 2012. However, at the time of he accident, just over 2 years later, “a concrete hazard and risk analysis had not been conducted in the company”, even though a functioning SMS as required of AOC holders by 28 October 2014. In this case it appears the SMS was still in development. In other organisations it has been apparent after accidents that the documented SMS was not an effective, living system but in practice was just ‘shelfware’ (as we recently discussed in the case of Metro-North).
Equally the German military procedures for Renegade interceptions “were neither described in detail nor assessed by way of risk analysis”.
The BFU concluded that the ‘Immediate Causes’ were:
- During positioning for the intervention the collision risk due to unexpected manoeuvres of the intercepted airplane was not sufficiently taken into consideration.
- The Learjet crew did not take into account the risks due to possible limitations of the field of vision and the distraction by using the computer [i.e. an Electronic Flight Bag] when deciding about the task distribution.
- Due to insufficient situational awareness during the intervention, the Learjet crew continued the turn with an excessive bank angle despite the loss of visual contact with the Eurofighter flying at the inside of the turn.
The BFU identified the following ‘Systemic Causes’:
- The operator had not specified in detail how the crew should distribute their tasks during Renegade exercises.
- Neither the operator commissioned to conduct the aerial target demonstration nor the Air Force had sufficiently described the Renegade training nor had a commensurate risk analysis been done.
The BFU issued a six safety recommendations. These are addressed to the operator, the Luftfahrt-Bundesamt (German civil aviation authority, LBA), the European Aviation Safety Agency (EASA), and the Luftfahrtamt der Bundeswehr (the German Military Aviation Authority, LufABw).
Mid air collisions are a significant military air safety risk and are the UK Military Aviation Authority (MAA) has identified this in all their annual reports since their formation.
UPDATE 20 November 2016: We report on a Military Airprox in Sweden
UPDATE 2 June 2017: Avoiding Mid Air Collisions: 5 Seconds to Impact