sys read up on the lanc, many a pilot have said she handles like a much smaller twin engined plane, she could very easily be barrel rolled and there are examples of her being put through an entire loop-the-loop at night to evade german fighters................
also it's generally accepted that 90% of attacking fighters would break off an attack if they knew the rear gunner of the bomber had seen them (normally indicated by a burst of fire), it was much easier for the attacking fighter to go off and look for another plane with a less vigilant crew, why? because he knows once he's spotted, unlike the Americans, the RAF bombers would go into evasive manoeuvres so...
You do it once and the fighter comes around for another pass
...isn't true at night..........
Of course you have also now bled off a lot of energy doing it and youre not going to pick up airspeed quickly unless you dive. And you can only do that for so many times before you run out of altitude.
let me introduce you to one of the more common "evasive" manoeuvres, it's actually very simple and quite hard to counter, ok, so, the rear gunner of a lanc at night sees an attacking fighter getting into position, he gives it a few bursts to see if he can scare jerry off, but jerry's more determined, so, the rear gunner sees the fighter closing in (they often had to get in close in order to identify the target) so he shouts to the flight engineer over the intercom "attacking fighter- prepare to drop" to which he hopes to get the reply "prepared to drop", then, when the rear gunner shouts "DROP" what do you think the flight engineer does? speed up? tells the pilot to go into violent manoeuvres? no, he all but closes all the throttles! this causes the aircraft to slow down very quickly, what's the point of this? well now jerry's going to overshoot! and will more than likely not come round again, and don't even think about a head on pass! opening of the throttles would then bring the aircraft beck to normal, total time for manoeuvre? 5-10 seconds? so not only was loosing speed used as a defence, this would only be done if the aircraft would gain speed quickly again, which the lanc did, this move was sometimes combined with a corkscrew, sometimes it would be very effective, sometimes jerry was a bit wiser, well, you win some you loose some...............