Lawmakers want a rapid fleet-wide upgrade to traffic collision-avoidance system (TCAS) software in a bid to avoid the potential of a mid-air collision over Europe on average every three years.
In a written question, Brian Simpson UK MEP and leader of the Socialist group of the European Parliamentary transport committee, requested an indication of how and when the European Commission planned to take action with the European Aviation Safety Agency to resolve two known critical weaknesses that had been identified through Eurocontrol's Safety Issue Rectification Extension Plus (SIRE+) project.
"[We are] aware of the findings of the SIRE+ research project undertaken by Eurocontrol," says the EC. "Therefore, the Commission agrees to an urgent need to integrate related two improvements called CP112E and CP115 to mitigate this situation via a fleet wide TCAS software upgrade."
Researchers identified eight other occurrences in Europe over a recent five-year period resulting in severe losses of separation where collision was only avoided by chance. Recommending an "aggressive" transition to a new version of the TCAS 7.1 standard, they estimated that without the upgrade, aircraft in European airspace faced a risk equivalent to a mid-air collision every three years, while a revision of the standard could increase that interval up to 12 years.
The first modification, CP112E, would resolve geometries similar to the "vertical chase" scenario that led to the mid-air collision between a Tupolev Tu-154 and a Boeing 757 over ¨Überlingen, Germany in July 2002. Both aircraft descended and collided when the Tu-154 crew failed to obey a TCAS 'climb' instruction.
A second modification, CP115, would replace TCAS's ambiguous "adjust vertical speed" instruction with a simpler "level off" order, preventing pilots' inadvertently responding incorrectly and making the conflict worse.
The EC is now examining whether an amendment of the related EASA technical certification requirements for airborne equipment could provide "the adequate solution" to address this safety issue or whether it would need to wait until EASA is given the go ahead to extend its rule-making and control remit to air traffic management safety.
Source: Flight International
