I agree with dididothat. The TBL should never be attached whilst the engines are running. Why exactly would the engines stay live until you've connected it up?? for a start, it means putting the bypass pin in, and relying on the captain to have actualy set his brakes. The aircraft should be chocked by the mains wheels whilst the tug is connected, and then removed....none of which can be done while the engines are running for obvious reasons. ive towed aircraft in to the apron before because of the proximty of the engines to other aircraft or buildings etc, but they would ALWAYS shut down before connecting even a conventional tug. all sounds very dodgy to me.....a few SOP's need looking at and rewritting id say