NavList:

One of the strangest decisions with regards to units of speed and distance is that of Bomber Command, Royal Air Force to change from statute to nautical miles and mph to knots on 1^st April 1945, only six weeks before WW2 might have been expected to end in Europe .  You can’t say Bert Harris didn’t have a sense of humour.

Wondering if this might have been quietly shelved by the Squadrons until hostilities in Europe ceased, I decided to check the logs and charts of Fg Off Denis Pybus, the Navigator on the McRae Crew of 463 Sqn RAAF, an Australian Squadron within No 5 Gp, Bomber Command flying from RAF Waddington.  The logs and charts shown are for a raid to Wesel on 23^rd March 1945 and a raid to Nordhausen on 4^th April 1945.  If you compare the rectified air speeds shown as RAS on the flight plans, those on 4^th April are consistently around 30 units less than those on 23^rd March.

Turning to the charts, on 23^rd March the distance from Turning Point D to Wesel measures 39nm using dividers, but Pybus writes 45 on his Flight Plan.  Note also that the 006E Meridian on the chart has two scales, nm on the left and statute miles on the right. Confused yet?  However, on 4^th of April, the distance from point D to Nordhausen measures 42nm, and Pybus writes 42 on his flight plan, thus proving 463 Squadron obeyed the order to covert from mph to kts very close to the date ordered.  DaveP

File:

File: