Bristol Blenheim part two, the Bollingbrokes and Canadian Blenheims

 

The Bristol-Fairchild Bollingbroke was a maritime patrol aircraft which was also used as a trainer by the Royal Canadian Air Force (RCAF) during World War 2. It was built by Fairchild-Canada and was, itself, a licensed version of the Bristol Blenheim Mk.IV bomber.

Its origins can be traced back to 1937 when, in order to modernize and expand the RCAF, the Canadian Government selected the Bristol Type 149 (internal designation given by Bristol to the Blenheim) which was offered by Bristol, though they proposed the type to be powered by Bristol Aquila engines to have an improved range. This was made to meet the official requirement G24/35 which sought for an aircraft with coastal reconnaissance and light bomber functions to replace the Avro Anson. The Canadian Government also acquired a production license for the Bristol Blenheim by Fairchild-Canada. The first batch of 18 was shortly after ordered and components to begin production were shipped, so in the latter half of 1939 a complete production chain was already set up.

The RCAF held the original name of the Blenheim (Bollingbroke) and applied its own mark numbers. The production variants were as follows:

• Bollingbroke Mk.I: The Bollingbroke Mk.I was the original Bristol Mercury VIII-powered variant, which was intended to be used in the maritime reconnaissance role and had British equipment. A total of 18 machines were built, but, eventually they were only used in the trainer role, for which purpose two of them were fitted with dual controls. 
• Bollingbroke Mk.II: The Mk.II variant were five Mk.I modified with internal US equipment. This served as the prototype for the Mk.IV.
• Bollingbroke Mk.III: One Bollingbroke Mk.I was fitted with floaters and received the denomination of Mk.III.
• Bollingbroke Mk.IV: The main production variant. It was powered by two Bristol Mercury XV radial engines rated at 920 hp each. This version was fitted for the long-range reconnaissance role and was equipped with anti-icing boots and, in some cases, a dinghy boat. A total of 134 machines were built at Fairchild's factory in Longueil, Quebec. 
• Mk.IVW: In order to cope with the possible interruption in supply of Mercury engines, a sub-variant was made by fitting an American-built Pratt & Whitney SB4G Twin Wasp Junior Radial engines rated at 825 hp each. This was the Mk.IVW variant of which a total of 14, plus one prototype were made. 
• Mk.IVC: Another single aircraft was also fitted with a 900 hp Wright R-1820 Cyclone engine and was designated Mk.IVC. 
• Mk.IVT: The most numerous sub-variant of the Mk.IV.  In this sub-version, 350 machines kept the original Mercury XV engines, while 107 additional ones were powered by the Bristol Mercury XX engine modified to be fueled by low-octane fuel. It was fitted for the gunnery and navigation training role and made a big contribution to the Commonwealth Air Training Plan. 
  A total of 457 Mk.IVT were built with a further 51 cancelled. Six Mk.IVT were fitted with dual controls and 89 of them were converted to the target-tug role, for which they were fitted with winching gear in the rear cabin and target drogue storage in the bomb bay. They were unofficially refferred to as Mk.IVTT.

The following combat squadrons of the RCAF were equipped with the Bollingbroke at any time of their existence:

• No.8 Squadron: This was the first RCAF squadron to employ the Bollingbroke operationally. It was formed at RCAF Station Sydney, Nova Scotia in December 1940. When Japan declared war on the Allied, the squadron was transferred to the Canadian west coast and between June 1942 and December 1943, it served alongside US forces in the Aleutian Campaign. 
• No.115 Squadron: This squadron was reformed with Bollingbrokes in August 1941 and served in Alaska too. An aircraft of this squadron damaged a Japanese submarine off the Aleutians on 7th July 1942.
• No.119 Squadron: The No.119 which was formed at RCAF Yarmouth, Nova Scotia. This squadron had its Mk.Is fitted with gun packs to serve as heavy fighters, just like the Blenheim Mk.IVf. No.119 remained with the Eastern Command, flying patrols over the Gulf of St. Lawrence until it was re-equipped with Lockheed Hudsons in mid-1942.
• No.147 Squadron: Formed at RCAF Sea Island, British Columbia, in July 1942. This unit operated the Bollingbroke from its inception until March 1944 and flew around 560 operational patrols on the Canadian west coast.
• No.13 Squadron: This unit provided Operational Training at RCAF Patricia Bay, British Columbia between October 1941 and June 1942.

Apart from those unit, the MK.IVT was also extensively used by various bombing and gunnery schools and service flying schools of the British Commonwealth Air Training Plan.

The RCAF was also equipped, albeit partially, with British-made Blenheim in their Europe-based squadrons. It's known that Nos.404, 406, 407 and 415 RCAF squadrons, serving under Royal Air Force's Command, operated the Blenheim too in the United Kingdom.

 

Sources:

1. https://en.wikipedia.org/wiki/Bristol_Bolingbroke

2. Hall Park Books - Warpaint 26 - Bristol Blenheim

3. Osprey - Combat Aircraft 5 - Blenheim Squadrons of World War 2