Twenty of the thirty eight B-17Cs produced were delivered to the RAF in the spring and early summer of 1941 where they received the designation Fortress 1. Eight of the twenty aircraft were lost in two months during daylight bombing raids and the Fortress was withdrawn from operations over Europe in the bombing role.

The aircraft were transferred to Coastal Command. with No. 220 squadron took over the Fortress Is operating them in the Far East for two months, before receiving the Fortress II, which was used for anti-submarine patrols over the Atlantic.

RAF Fortress 1 of 90 Squadron. Designated by the squadron code WP. 206 had the squadron code VX from Sep 1939 – Mar 1944.

These were augmented starting in July 1942 by 45 Fortress Mk.IIA (B-17E) followed by 19 Fortress Mk II (B-17F) and three Fortress Mk III (B-17G).

Fortress Mark IIA, FK212 ‘V’, of No. 220 Squadron RAF based at Benbecula in the Outer Hebrides, in flight over the Atlantic Ocean. FK212 failed to return from a patrol on 14 June 1943. IWM Archive.

In August 1942 whilst based in Benbecula, 206 Squadron began to convert to the Fortress, and in October it moved to the Azores.  A Fortress IIA from No. 206 Squadron RAF sank U-627 on 27 October 1942, the first of 11 U-boat kills credited to RAF Fortress bombers during the war. The squadron remained on the Azores until March 1944, and during this period achieved five of its seven confirmed U-boat sinkings, all of which came in the North Atlantic and the waters around Iceland and the Faroe Islands, a long way to the north of its new base.

Publicity shot purporting to show the captain of a Boeing Fortress Mark II of Coastal Command holding a final crew brief before taking off. The photograph was taken at Benbecula in the Outer Hebrides in front of a Fortress Mark II, FL462 ‘W’ of No. 220 Squadron. The ‘crew’ were, in fact, an ad hoc group drawn from No. 206 Squadron. IWM Archive.

Coastal Command Fortresses were equipped with ASV.II with a forward looking or “Homing” Yagi aerial configuration. It normally featured a single transmit aerial in the nose and a receiving aerial under each wing angled out by 20-45 degrees from the airframe centreline.  The second aerial array was the sideways looking “Search” array. This had a transmitter array or four aerials along the spine of the aircraft and two rows of four receiver aerials along each side of the aircraft. This gave longer detection range. This was used to search for a target then, when something was found, the aircraft would turn and use the shorter range forward looking Yagi array to home in on it for an attack.

Credits:

Header Image: Gaëtan Marie. Boeing Fortress Mk II FA704 Commanded by Wing Commander R. B. Thompson, 206 Squadron, flown from  RAF Benbecula, Outer Hebrides, Scotland. Sank German Type VII C submarine U-417 on 11 June 1943.

Fortress outlines: Weapons and Warefare

Photos: Imperial War Museum Archive