I just wonder why they continued to climb on the BPK SID when they lost the cowlings right after takeoff
In addition to overstress's valid comments:
I've operated out of Northolt many times. The CPT 4Y departure that we use steps from 3,000 to 4,000 then 5,000ft while flying North then North West from runway 25. This SID cuts straight across the path of the BA flight. If he hadn't climbed he might have had to deal with a TCAS in addition to everything else. Just because one aircraft has an emergency doesn't mean all the others disappear. It takes time to move them out of the way. He made a good call to stay with the clearance. That's what ATC would expect so they would vector other traffic on that basis. He couldn't know that as it transpired there were no departures from EGWU at that time.