Cliffnemo.
I have finally tracked down a beam approach procedure in writing. It’s for a Halifax but I am sure that a Lancaster would have been the same.
Looking at that the modern equivalent of decision height would have been 100 ft.
My father once explained to me the ‘Timed Circuit’. This was a procedure to get his Halifax on to the runway when there was a sheet of low stratus over the airfield, especially at St.Eval or Brawdy.
You would be homed on to the airfield using a manual homer so that you were approximately on the runway heading and when they heard you coming they would fire a ‘porker’, a parachute flare, vertically upwards from the tower. Seeing this above the cloud you would aim to just miss it and as you passed it you turned downwind on the runway reciprocal heading using about 30 degrees of bank. Rolling out you would fly for one minute dropping the Dunlops etc and at the end of that you would do a descending turn using 25 degrees of bank so as to keep the radius of turn the same. If everything worked out you would be pointing on the runway heading with the flare gasping its last in front of you. You then descended into the murk At about 2-300 feet you could pick out the wreckage from the people who had tried it before and then you followed that to the runway.
I tried it a few times in the early sixties, not for real, but it worked out every time.
My father’s biggest claim to fame was that he changed the date of D Day. He was on 517 (Met) Sqn. On June 1/2 1944 he did a special weather reconnaissance flight off Western Europe and as a result of this the decision was made to postpone the Normandy Invasion by 24 hours.