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« Last post by apophenia on Today at 04:31:26 AM »
This one is partially based in reality. The RCAF really did consider the Bell Model 1 'convoy fighter' - aka Airacuda - as a potential long-range, over-ocean heavy fighter. With US military aircraft export attitudes of the day that choice all but guaranteed failure. However, that brief foray by DND into heavy fighters in 1938 opened the way into my playing with a domestic Bolingbroke heavy fighter. And who could resist that?
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Brock - The Bolingbroke Fighter (Part 1)
In February 1938, the RCAF issued a requirement for a fast, 2-seat, twin-engined, long-range fighter aircraft of all-metal construction. This machine was to be capable of mounting on wheels, skis, or floats. According to RCAF Specification C/3/38, armament would consist of fixed nose- and wing-mounted machine guns as well as a mid-upper turret.
With no suitable British designs then available, a Canadian delegation went to Washington in April 1938. Discussions with USAAC representatives revealed that the Curtiss A-18 was the only available US twin-engined design which might match the RCAF specification. However, the Canadian delegation was more interested in the experiment Bell Model 1 'convoy fighter' - a long-range, multi-seat, twin-engined bomber destroyer.
An Airacuda for the RCAF?
First flown in September 1937, the Bell Model 1 was adopted by the Air Corps as the XFM-1 Airacuda. This was followed by 8 x modified Bell Model 7s taken on as YFM-1s. However, deliveries would be slow - with the last Airacuda not being turned over to the USAAC until October of 1940. The US Neutrality Act also complicated matters, since no American-made aircraft could be approved for export - in whole or as a production license - until after its second production airframe had been delivered to the USAAC.
Beyond the challenges of US export approval, the Department of National Defence also concluded that the large and complex Airacuda was also much too expensive - a common issue with American-built aircraft of the day. The head of the RCAF Aeronautical Engineering Division, Group Captain E. W. Stedman, made a recommendation to examine Bell Aircraft's Model 9 - a proposed simplified Airacuda development. The Model 9 eliminated the Model 1's forward-firing cannon stations. This, in turn, allowed for tractor propellers - which both improved handling (due to slipstream air flow) and more engine options. [1]
An Almost Was - the Bell Model 9(CAN) Barracuda
The initial Model 9a concept was to be powered by 2 x 1,050 hp Pratt & Whitney R-1830-S1C3-G Twin Wasp radials driving constant-speed Hamilton Standard 3T50 tractor propellers. Balance was restored by shortening the nose (the navigator being relocated to the central fuselage, leaving only the pilot in the extreme nose). To the rear was an observer/gunner who would also be responsible for reloading and troubleshooting the main, forward-firing armament.
Although the RCAF was uncertain about including a third crew member, this Model 9(CAN) - or Bell Barracuda for its mooted service name - had promise. However, even though the Model 9 was not on the USAAC order books, the American government was still less than happy at the prospect of exporting such an advanced machine. [2]
Top: The Bell Model 9(CAN) Barracuda concept in its final form. Neither forward-firing armament nor undercarriage arrangements had been fully decided when the Model 9(CAN) project was cancelled.
Turning Inward if not Exactly Homeward
In the meantime, the RCAF had ordered a similarly-sized twin-engined aircraft for the recce-bomber role. This was the Bristol 149 Blenheim IV which was to be built in Canada under license by Fairchild Aircraft at Longueuil, QC, as the Bolingbroke. G/C Stedman now turned his attention to the potential of adapting the Bolingbroke airframe to meet the objectives of RCAF Spec C/3/38.
At the request of the Department of National Defence and the Department of Trade and Commerce, Fairchild engineers provided briefs on three possible long-range fighter adaptations. The first option was to take on a supply of British-built, short-nosed Blenheim Mk.Is fitted with belly packs for 4 x .303-inch Browning guns. One alternative was fitting the Bolingbroke airframe with a narrower nose - clearly based on Bell's design - which would provide space to the sides for armament blast tubes.
The final option employed that new nose concept in combination with the lower-slung engine installation from the Bristol Beaufort torpedo bomber. While the first option was the simplest, its performance promised to be marginal. The ideal option was the third - which, with its lowered engines, would also have much superior visibility from its cockpit. [3] In the end, the second option was accepted and quickly implimented.
Fairchild's Bristol 149C Brock Heavy Fighter
To speed production of the Canadian-built Bolingbroke bombers, Fairchild acquired several partially-complete Blenheim Is as pattern airframes. Once they had served their purpose, Fairchild used four Blenheim I airframes to rapidly create pre-production trials aircraft for the RCAF's heavy fighter programme. Although not fully representative, these aircraft were redelivered to the RCAF for testing. Initially referred to as 'Blenheim HFs' while on trials, once accepted for service, the pre-production machines became Bristol Brock Mk.Is. [4]
The Brock Mk.I was in no way fully representative of the type. Being based on Blenheim I airframes, the pre-production Brocks lacked the Bolingbrokes long-range wing tanks (and their associated fuel-dump pipes). As a result of this slightly-reduced range, the two Brock Mk.Is tended to be employed by No.118 Squadron on closer-in patrols of the approaches to Bedford Bay. However, the main value of the Brock Mk.Is was to test the heavy fighter modifications to establish whether any other changes would be needed.
Bottom: A Fairchild (Bristol) Brock Mk.I heavy fighter in service with No.118 (Fighter) Squadron RCAF at Dartmouth, NS, in early 1941. Technically, Brock 9034 was a Mk.IA (having been re-fitted with the Mk.II's 3-part windscreen). Note the early-type DF loop and that this aircraft has been equipped with Bolingbroke-like US-supplied radio kit.
This Brock Mk.IA suffered a ground looping accident upon landing at RCAF Station Derbert, NS, in April 1942. The damaged airframe, with its undercarriage locked down, was then shuttled to Relief Landing Field Scoudouc-R1 (10 miles NE of Moncton, NB). There, after assessment by personnel of No.4 Repair Depot, Brock 9034 was stripped of usable components. The hulk was then transferred to BCATP Station Moncton for fire-fighting practice.
The pre-production Brock Mk.Is would be quickly followed by full series production Brock Mk.IIs based on Fairchild's Bolingbroke Mk.I airframes.
(To be continued ...)
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[1] An unwillingness to share the Model 1's pusher-prop Allison V-1710-23 engines had been a major hurdle in gaining export approval for the Bell 'convoy fighter'.
[2] It turned out that this American reluctance had more to do with concerns over distracting Bell Aircraft from perfecting their promised XP-39 Airacobra single-engined fighter for the USAAC.
[3] The Beaufort had also been designed to accept alternative American engines - the same P&W R-1830 radials put forward in the aborted Bell Model 9(CAN) proposal.
[4] The aircraft was named for Major-General Sir Isaac Brock, KB, a hero of the War of 1812.
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