WWII items from my Grandfather

[Gatorade]

Originally Posted by Night Owl

I think the 3” card is a compass correction card. Most aircraft have a primary compass system and a backup compass system. The backup system was very inaccurate and the easiest way to correct for the error was to fly a slight correction, or deflection, for the actual heading the pilot wanted to fly.

North can be shown either as 0 degrees or 360 degrees since there are 360 degrees in a circle. 180 degrees represents South. The error for this compass flying due north or due South is zero. That means to fly a course due North or South, the pilot didn’t apply any correction.

This compass had primarily an error when flying East or West. If the primary compass system failed and the pilot had to fly off of the back-up system, this card indicated the indicated course to fly to get the desired result.

To fly north, the pilot would fly an indicated 360 heading. The fly southeast on a direction of 120 degrees, there is a correction of 4 degrees. Usually -4 means the pilot would indicate 116 degrees on the compass. To fly a southwest course of 240 degrees, the pilot would fly a corrected heading of 244 degrees.

To determine the corrections, the technicians would paint a compass rose on the ramp and taxi the aircraft out to the rose. They would point the aircraft to each heading, and then let the 'whiskey compass' settle down and read the indicated heading. They would write down the corrections for each heading and then mount this card on the instrument panel next to the compass. The card could easily be replaced in case the stand-by compass needed to be replaced. After replacement, they would have to ‘swing’ the new compass around the compass rose and install a replacement card. That's why your grandfather could easily swipe this one from the cockpit.

Today they ‘swing’ the compasses with electronic test kits.

The name and serial number of the individual that swung the compass and published the new card was entered at the top of the card. Usually the technician and his supervisor both entered their names and serial numbers to prove that the work was double checked. Since I don’t read or speak German, so I can’t translate the data at the top of the card.

You should be able to Google the German words by typing “Translate Ablenkungstafel” into the search box. The answer is “deflection panel.” We call this card a correction card and apparently the Germans called it a deflection panel.

I hope this helps.

Owl

Outstanding information! I now know what this is and why it was important. All I ever knew was where he got it and it was a compas card. I am guessing it was not exclusive to the Messerschmidt 262 but all aircraft that had that type of a back up compas. Still his eyes light up when he thinks back to being in that cockpit. I will relay the information to him so he knows exactly what it is as well.