The 8-Group Form "B" for 5/6-March-1945, Chemnitz, refers to the "Y" method, which I am pretty sure is the release, variously, of Flares, T.I.'s or bombs, blindly using Radar. For example:
"2. Supporters at H-6 1/2 Must be on time. They will bomb the aiming point on their first run and will do so visually or blindly according to the Y method...
3. Blind Illuminators at H-6. Will drop blindly flares flares illuminating across the aiming point (6 second intervals) and drop bombs on the aiming point using the Y Method Passed [Sic]. If Y is U/SS [Sic] They will revert to illuminating blindly at H-5..."
Examination of the ORB's and other entries in this Form "B", I am pretty certain the Y method requires a functioning H2S. The 405 Squadron ORB for this operation refers to two A/C that were unable to mark "as S/E U/S" and therefore bombed as Main Force.
Has anyone come across documents that describe the "Y" method?
Edit: My speculation on the meaning of "Y" removed as per my next post.