[Tony Williams]

Originally Posted by smidon

My question ... was Schräge Musik operational for the best part of two years without the RAF being at all aware of it ? What a coup.

Another quote from FG:WW2

"The RAF has been criticised for its slowness in identifying the cause of these losses and finding some countermeasure. In Luftwaffe circles it was assumed that Schräge Musik would be of value only as long as the RAF was unaware of its existence, a consideration which prompted a panic when, on 28 April 1944, a Bf 110G with oblique cannon and Lichtenstein SN‑2 radar landed in Switzerland. (A deal was reached in which the Swiss were sold 12 Bf 109G‑6 fighters for a price of six million francs, and the aircraft was destroyed.) As mentioned above, there was a long history of experiments with upward-firing firing guns in Britain, and even some operational use. It should not have been a surprise that the Germans would employ a similar weapons system. On the other hand, this knowledge alone would not have produced an effective countermeasure. If the crews of Bomber Command were unaware of the existence of Schräge Musik right until the end of the war, the cause is probably that those in higher ranks felt that no useful purpose was served by informing them."

Tony Williams: Military gun and ammunition website and discussion forum