dogle (welcome back) and Smudge,
On the Vengeance, we used the dive brakes (apart from dives) merely to reduce speed down to circuit speed, or in case of coming up at 150 mph behind a formation trundling along at 130 mph, to avoid ramming the man in front.
Any attempt to use them at circuit or approach speed would result in an alarming loss of lift (any Meteor driver who has dropped wheels and flap, forgetting the brakes were still out, will know the effect).
In the case of a slow-flying Vengeance, it would promptly revert to "brick" mode. Not to be recommended.
As for gliders, from what little I know, the idea was to use them as "reverse throttles", so you always had a bit in hand if needed. But your airbrakes were as puling kittens in comparison with the roaring tigers of the ones on the Vengeance, designed to hold 7 tons, descending vertically under partial power, to a terminal velocity of 300 mph.
My unfortunate mishap in Burma was my own fault. Having got it into my head that all I had was an instrument failure, and nothing to worry about, I came down to circuit height (1,000 ft) instead of holding on to the 3,000 I had. This would have given me a chance of a 'dead-stick' if I got close enough to the strip, or of us going over the side if not.
As it was, I guessed wrong and still bear the scars.
The place with the harbour was Chittagong. I had my prang from some kutcha strip off in the bundoo. Can't remember a name.
Never tried opening a DV panel. Think it would be rather draughty.
Cheers, Danny