Fokker were trying to market the civil F.27 Friendship for military use.  This one for maritime patrolling as the 'Maritime Enforcer' and the one behind as a 'sort of' mini AWACS' as the 'Fokker Sentinel'. (sorry about the people... you can't really get rid of them at an airshow!)
Ken Fielding
CC BY-SA 3.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/kenfielding/12431271473/">Flickr</a>