One of the fleet had a de-icing failure on a trip back across the alps. The tail got steadily heavier and the speed fell down and down - but the stall warning never operated at the speed (or lack of it) quoted in the manual. We then spent many happy hours investigating, measuring and test flying to set up the stall warning to operate at a higher margin. I recall putting our test gear on the flight deck with loads of wires sprouting out of the electrical "wardrobe" next to the Flt Eng's station. We then went flying or I should say stalling, all over Oxfordshire and Wiltshire. One stall at each flap setting on each stall warning system nearly a dozen each trip I think...
In the course of this adventure we discovered that the Belfast loses 5,000 feet in recovering from a clean stall. I did manage to hang on to my breakfast but kept my packed lunch to eat in the crew room later. When the Belfasts went onto the civil register the CAA were so alarmed by these stall characteristics they insisted on a stick pusher - but then the Redhill mob would have wanted a stick pusher on the Spitfire if they'd had any say.
The Belfast was a dreadful beast to work on but we got lots of overseas detachments doing engine changes. Up until 1974, 364 held the record - five engine changes on one Eastabout through Oz and Honkers. I did the one in Gan - it took us five days to adjust the take-off power. Rolls Royce provided charts that went right down to minus 35 but only went up to plus 25. The lowest temperature ever recorded at Gan was 27, so we had to interpolate and do the runs at 2 am until we got it right. (The Rolls Royce charts worked fine for the guys who got the engine change in Gander though.)
The Belfast was a good test of engineering skills, that's for sure...
BTW, in the 70's we didn't call them Belslows, on Brize LSS they were known as "Belslugs."