F2b 50th Anni first UK Regular Air Mail Service Folkestone to Cologne

The covers were flown from RAF Northolt via Coloogne to RAF Wildenrath in Pembroke XK734 and return. The covers were cancelled during the flight with BFPS 1077 handstamp.

Unsigned variant
This is the error version - with BFPS 1077 postmark and received Folkestone - should have had BFPS 1076 and Received Koln. Cover has red border