<p>Sight Log Book from the Royal Air Force.
</p>
The "spotter" creation I suppose.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/38862883@N07">Carlos Menendez San Juan</a>
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/carlos346/3874340376/">Sight Log Book</a>