A federal judge has ruled to keep in place an order requiring that American Airlines mechanics' unions work to achieve productivity levels equal to 2018 levels.

The 16 July order from US district judge John McBryde strikes another blow against the unions, which have been accused by American, in a legal suit, of orchestrating a work slowdown.

American's suit names the TWU-IAM Association, the International Association of Machinists and Aerospace Workers (IAM) and the Transport Workers Union (TWU). The TWU-IAM Association is negotiating with American to bring the TWU and IAM work groups under a single contract.

Judge McBryde had ruled on 10 July that the union must work to meet the 2018 productivity levels.

But the union quickly filed a motion asking that the productivity benchmark be struck out on the grounds of negative effect on safety.

McBryde has now denied that motion.

"Defendants have expressed concern that if they take actions contemplated by the modification of the temporary restraining order, they will cause their members to take actions that could adversely affect the safety of the travelling public," notes McBryde's ruling.

"However, they have provided nothing in support of that position that would cause the court to believe that the members of defendants do not have good enough judgement to know when they are doing something that would adversely affect the travelling public."

The unions did not immediately respond to a request for comment.

Source: Cirium Dashboard