Brian: Reykjavik at 64.12 degrees N and 21.86 degrees West. This website for March 15, 1945 provides an estimate of -27.3 degrees for magnetic declination.

https://www.geomag.nrcan.gc.ca/calc/...e_direction=-1

So a heading of 345 degrees True (NNW) would equate to 345+27-360 or a compass heading of 12 degrees, i.e. NNE. Does my logic make sense?

"D: magnetic declination, defined as the angle between true north (geographic north) and the magnetic north (the horizontal component of the field). D is positive eastward of true North." This makes sense as Magnetic North is over Canada, pulling the compass bearing considerably "West" in the vicinity of Reykjavik that far north. In order to correct, you would have to steer considerably East, so a compass heading of 12 degrees, QDM makes sense.

Here are a couple of other considerations. 1) the nature of the metals on the aircraft will affect the compass. A compass card was used to correct for these but I have not been able to determine how this was corrected in calculations. 2) there would undoubtedly be local magnetic anomalies that would affect compasses. These may not have been properly charted in WWII. Edit: update. Charted magnetic anomalies in the region of the crash site:

https://notendur.hi.is/leo/pdf/J67p43-49LKGJ.pdf

NB: I have found the estimates for magnetic declination from this Gov't of Canada model provide results within a degree or so of those indicated on Bomber Command navigation charts.

Jim

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