Periscopic drift sight.

[canti44]

Any ideas to what these drift sights are from? I'm assuming an aircraft but that's all I know about it. Cheers.

[Battery Command Post]

It's definitely RAF, whatever it is. The stores code leaves no doubt on that: Code No 6B/356.

RAF stores with the prefix 6B/ are "Aircraft Navigation Equipment, Accessories and Spares", so it's something to do with that.

Rob

[canti44]

Cheers Rob,

nice bit of information there. That gives me something to work on. I can't find a date on it anywhere - any ideas?

[dogdog47]

Hi these were used on bombers. i think a smoke flare was dropped and this was used to calculate drift due to weather and wind conditions etc for the bomb run.
the results would be fed into the bomb sight.
at least that is how i understand it.
hope this helps.
Andy

[canti44]

Hi Andy thanks for that. What era are we talking here do you think? 'Made in Great Britain' at the foot of the serial number plate sounds post-war to me.

[Battery Command Post]

I think it's more af a general navigation item than part of the bombsight per se, although, of course, accurate navigation is crucial when bombing. I did a bit of reading up on this and found that drift is the angle between the plotted heading and the plane's actual heading, the difference being caused by the wind blowing the aircraft sideways. The principles for calculating 'drift angle' in terms of aircraft navigation are explained nicely here: Wind triangle - Wikipedia, the free encyclopedia.

All kinds of aircraft had drift sights, including non-military ones. I have an RAF manual of Air Pilotage somewhere, I will see if it has anything in it.

Rob