At weekends I'm quite close to Duxford, where the Imperial War Museum's plane collection is kept and where they have displays through the summer, so it's not uncommon to hear the wonderful throaty sound of Merlin engines over the house - especially when the Battle of Britain Memorial Flight is going over on its way from Lincs.
For those in the US, the BOBMF is a Lancaster, Spitfire and Hurricane kept in pristine condition and flying around 600 hours a year at displays and over state events and the like. As for the difference between the Spitfire and the Hurricane, I've heard it described as between a fesity thoroughbred and a realiable old carthourse - the Hurricane wasn't as manoeuvrable but was a lot more forgiving and could absorb a lot more damage than the Spit. Not as pretty, though (and, sorry Owlkat, but there can be a terrible beauty even about things which are designed to deal in death - IMO at least).
The Lancaster is a wonderfully noisy beast, and I can only boggle at what it must have been like with the sky was full of them.
My step-grandfather flew Lancs (the rotten sod was responsible for much lf the damage inflicted on Milan and Turin - so on his behalf to anyone there, sorry). On the subject of blivets and what to do with the waste matter of the crew on a long op, he would wax lyrical. Apparently, on some planes, the pilot and co-pilot were allowed a piss-tube which led to the outside and down which they'd relive themselves while not leaving the flight deck. It paid to be pleasant to the ground crew, for those buggers that weren't would find that some erk had put a cork in the external opening of the piss-tube - meaning that the call of nature somewhere over occupied Europe would end up with a lap-full of freezing piss and some stinking flying suits once the tube backed up.
The bigger bombers also had chemical toilets on board - the old-fashioned Elsans. My grandfather used to swear (though it may be apocryphal) that some crews would chuck the bugger out through the bomb-bay on the way back rather than have it slopping its contents around the plane in rough weather - and that the Nazis actually put in a formal protest through the Swiss Red Cross to the effect that the Brits were using chemical or biological weapons in contravention of the Geneva convention after finding some impacted Elsans in France and the low countries.
That's why, in my step-grandfather's honour, I always try and have a dump over Birmingham when flying north-south. The thought of all that blue ice falling on England's unloveliest cities... *BG* ;^)

(Ducks and runs, chased by angry Brummies!)