It's worthwhile mentioning the use of the Contact Altimeter Fl.22317 in Luftwaffe Dive Bombers. I didn't see it mentioned in the Ju87 A-1 manual above but possibly because that manual was for an early Ju87 model published in 1937. The Contact Altimeter was used in Ju87s and probably Ju88s and some Me110s during the 1940's. The altitude would be set to electrically actuate the bomb release mechanism upon descending to the selected altitude so that the pilot could concentrate on the dive maneuver.
In the image below, the center of the two-part knob marked with the "K" was used to set the trigger altitude shown by the red pointer. The knob's outer rim adjusted for barometric pressure using the inset center scale.
What I don't know is how the contact circuit was set to only trigger on a descent into a dive-bombing run and not when ascending or descending through that altitude in normal flight maneuvering. One might speculate that there was a switch on a panel somewhere to enable the contact altimeter release. Anyone know?
Contact Altimeter
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Here is a close up of the Ju87 blind flying panel showing its location.
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