Re:Norden bombsight transportation on airfields.
I was waiting for Bill Runnels to answer....my experience in Italy with the 15th AAF was the same as Bill's...the bombsights remained on the aircraft between missions.
If I recall correctly, the time period when the Norden Bombsights were guarded so highly secretive, was pre-war....(actually the Norden Bombsight was a developement of the U.S. Navy).
If one will look closely, on the data plate of each bombsight is a small Navy Anchor Inspector Stamp.
James S. Peters Sr. T/Sgt B-17 Flt Engr, 27 missions 99 BG, 348BS, 5th Wing, 15th AAF Tortorella, (Foggia#2), Italy My Tour was from 12/03/44-06/19/45 M/Sgt USAF (Retired)