It wasn't only senior NATS managers that got the sharp end of her tongue.
I remember a GATCO seminar where she shared the platform with several senior management types including one gentleman from BAW. When in response to a question from an ATCO in the audience, he whispered to her that he'd prefer to discuss the issue outside of the meeting, in an authoritative and almost majestic manner, she told him in a loud voice that the questioner wanted to discuss it there and then, and so he should provide the answer.
With an amazing intellect and ability to assess the issues from 'outside the box' Gwyneth D was one of only a handful of post-war UK politicians who had true integrity and principles.
The Labour Party and the Commons will be all the poorer for her passing away.