Apophenia's Offerings

[apophenia]

(Continuing ...)

Whif: The Arsenal VG 32 was Constructed in Canada?

To head the effort to build VG 32 fighters in Canada, representatives of the Anglo-French Purchasing Board sought out experienced British engineer Wilfrid Reid. [1] Reid was to become head designer at CABMA - the Compagnie d'avions en bois moulé d'Acadie (or Moulded Wooden Aircraft Company of Acadia). With production space at a premium around Montréal-area airfields, the Moncton area in Acadia - the French-speaking region of New Brunswick - was chose as the location for VG 32 production in Canada. [2]

Top: A view of what the unarmed Arsenal VG 32C1 N°1 might have looked like had it been completed. (This image is based upon a Arsenal VG 30 profile by Ed Jackson.) No main undercarriage fairings are shown (as none seemed ever to be fitted to production VG 33 airframes).

To aid Canadian production, Reid has contracted the services of US-based Aircraft Research Corp. to help redesign the VG 33's complicated, double-skinned fuselage structure for Gene Vidal's technique of using heat-activated phenol formaldehyde (PF) resins to bond wooden aircraft skins and stiffeners at the same time. [3] For its part, Arsenal de l'aéronautique provided a sample airframe - the engineless VG 33 N°03 - along with drawing for the planned Allison installation in the VG 32C1.

Meanwhile, a new manufacturing facility with its own airstrip was being created a few miles to the east of Moncton in Scoudouc, NB. Besides offices, this plant was comprised of two woodworking shops, a dedicated fuselage moulding facility, and an assembly hall. As the moulding hall was completed, work had already begun on wing components. These wings were based directly on the sample airframe. But this presented a problem - the resulting wings held only 4 x machine guns.

Once informed that insufficient HS 404 cannons were available to arm Canadian made VG 32s, CABMA began devising an alternative armament (with W. T. Reid calculating stressing). Upper cowl guns were rejected as, even in the absense of a cannon breech, there was inadequate space directly in front of the cockpit. The CABMA drawing office's solution was to mount a pair of synchronised guns in the lower cowling. To approximate the HS 404's weight of fire, twin 13.2 mm FN Browning guns were recommended.

Bottom The prototype 'Vidal-Arsenal' fighter - CABMA's VG 32 N°02. Removed cowling sections reveal the Allison V-1710-C15 engine and portside 0.50-inch Browning heavy machine gun (standing in for the planned 13.2 mm FN gun) with its spent casing collector box to the rear. Note also revised tail fin, refined tail cone, and great clearance provided by the new tailwheel.

The revised Vidal-Weldwood fuselage featured a structural join in the transverse plane. This approach greatly simplified fuselage construction but the fasteners joining the upper and lower segments (which connected level with the horizontal tail) reduced the overall weight savings of the Vidal-Weldwood Process.

(To be continued ...)

_____________________________________________

[1] In 1928, Wilfred Reid had left his chief aircraft designer's position at Canadian Vickers to form W T Reid Aircraft Co. in Montréal. By 1931, that firm had, in part, been acquired by the US-based Curtiss Company - becoming Curtiss-Reid. When the Depression killed Curtiss-Reid, W. T. Reid had turned his attention to diesel engines.

[2] Locating CABMA near Moncton also provided easy access to New Brunswick timbers - including aircraft-quality red spruce. However, some wood components required the use of sitka spruce which was shipped east from British Columbia.

[3] Anticipating, a need for wooden aircraft structures in wartime, W. T. Reid had licensed the Vidal-Weldwood Process from Aircraft Research Corp. in late 1938. Reid's initial plans to design a new, wooden training aircraft for the RCAF would be eclipsed by the French VG 32 contract. Similarly, CABMA absorbed a recently reformed W T Reid Aircraft Co. Ltd.

[apophenia]

(Continuing ...)

'Vee-Gee': Canadian Arsenal VG 32s into Production

To accommodate Canadian commerce rules, the Compagnie d'avions en bois moulé d'Acadie was majority-owned by Montréal-area businessmen (49%) including Wilfrid Reid himself (10%), leaving the French government with a minority 41% share. However, Paris - through the government's Arsenal de l'aéronautique - retained ownership of the basic VG 32 design. The production 'Vidal-Arsenal' VG 32C1 was identical in most respects to the VG 32 N°02 prototype.

Top: VG 32C1 N°04 served as an armament testbed for CABMA prior to its delivery to the French. It was fitted with the full intended armament of 2 x 13.2 mm FN Browning lower cowl guns and 4 x 7.5 mm MAC 34 machine guns in its wings. VG 32C1 N°04 was finally delivered to France in June 1940 but was still awaiting assembly at a Base de Stockage outside Saint-Nazaire when that Armée de l'Air facility was over-run by the Wehrmacht.

Only the first half dozen CABMA-built VG 32s were armed as originally intended. The AdA preferred to fit six 7.5 mm guns - generally 4 x MAC 34s in the wings and a pair of small-bore FN Brownings in the nose. [1] Weight of fire was reduced as a result but, the AdA reasoned, ammunition supply at the squadron level would be simplified.

Dans la mêlée - the Arsenal VG 32C1 in Service

On 13 May 1940, GC II/7 began re-equipping from MS 406 fighters to VG 32s. By 01 June, the Groupe had completed its transition to Arsenal fighters - but with some French-built VG 33C1s mixed in with the Canadian-made VG 32C1s. Blanc 3 was the personal mount of Sergent-Chef René Panhard - a pilote expert transferred from the VG 33-equipped 3ème to 4ème escadrille on VG 32C1s.

Bottom S/C Panhard's Allison-engined fighter received a red spinner and 'bouche de requin' personal marking. The individual aircraft number was blanc 3. The '4' on the vertical fin's disque noir denoted SPA 78 - the 4ème escadrille of Groupe de Chasse II/7. During the Battle of France, S/C Panhard had scored 5 x confirmed kills and 1 x probable.

After retreating to Algeria with GC II/7, S/C Panhard was demobilized on 15 Aug 1940 and returned to la métropole. His mount - VG 32C1 N° 26 - was eventually reissued to CG II/3 which then deployed to the Levant. In May 1941, an unserviceable VG 32C1 N° 26 was destroyed on the ground during an RAF strafing attack on the Vichy airfield at Alep (Aleppo).

(Fin)

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[1] This mix of machine gun types was dictated by the French MAC 34s lacking propeller synchronisation gears which the FN guns did have.

[GTX_Admin]

 

[apophenia]

Another 'palate-cleanser' ... and a rather goofy one at that!

I am imagining a post-March 1944 Erla Maschinenwerke GmbH's Leipzig area facilities flattened by Allied bombing. Amongst the ruins (or perhaps in Erla's Werk III at Abtnaundorf which survived largely intact?), a number of Bf 109G-10 fuselages were spared. Some would be incorporated into damaged 'G airframes before return to the Luftwaffe ... but how to employ the rest?

As it happened, Mitteldeutsche Metallwerke had Fw 190D-9 'Dora' wing sets on hand - which differed sufficiently from the wings of planned 'D-13 production to make them surplus. [1] Most of these wing sets would be delivered by road the 156 km from the 'Mimetall' factory in Erfurt to Abtnaundorf. There, these wings would be incorporated into a hybrid fighter design based on Bf 109G-10 fuselages and Jumo 213A powerplants similar to those of the 'Dora'. [2]

This hybrid aircraft was viewed as a lightweight fighter which was reflected in its armament of 4 x wing-mounted MG 151/20 cannons (no motorkanone or cowl guns being fitted). These 4 x 20 mm were considered adequate for counter-fighter duties (even if overly light for tackling Allied heavy bombers). The RLM re-assigned their 8-409 designation from Messerschmitt [3] to Erla resulting in the hybrid fighter being designated Er 409.

Although famous for their late-model Messerschmitt 'Erla Haube' canopies, Erla chose to fit the Er 409 with a Fw 190D-9 sliding canopy modified to suit the Bf 109G fuselage. This also allowed the cockpit to be raised slightly - giving the pilot a better all-around view (including over the longer nose) as well as providing space for a small fuel tank directly beneath the cockpit.

It is not clear whether any Erla Er 409 fighters were ever issued to a frontline Luftwaffe squadron. If they had been, parts would have needed to be sourced from both Messerschmitt and Focke Wulf supplies. Doubtless, the Er 409s would also have suffered from some degree of sabotage from Erla's doomed slave labour force. In any case, the Untergang des Dritten Reiches was imminent and Erla's efforts could do nothing to further that ruinous regime.

__________________________________________

[1] Some wing sets were bound for Weser Flugzeug at Nordenham where the plant devastated in July 1944 had been prepared sufficiently to begin Langnase Fw 190D production. However, due to incessant Allied bombing, no Weser-built Fw 190D-13s were ever completed before the ultimate Zusammenbruch.

[2] The tailplane resembled that of the Bf 109 but was larger (including pushing the stern post aft for extra area) with a primarily wooden structure.

[3] At Messerschmitt, Me 409 had been the original designation for what became the Me 155B (later transferred to Blohm + Voss as the Bv 155 lineage).

[Glanini]

Very nice profiles

[apophenia]

Very nice profiles

Thanks Glanini. A highly improbable scenario ... but the profiles were fun to do 

[elmayerle]

- MV-75 by Bell Textron: Formerly the V-280 Valor, the MV-75 is a tiltrotor design still in the prototype stage for the US Army. Compared with the S-70A Black Hawk it is to replace, the MV-75 is longer-ranged and faster. But to gain that speed, it requires engines more powerful than those of the larger MV-22B Osprey.

Actually, now looking in from the outside, I believe the MV-75 uses the same engines as the MV-22B, but on a smaller and lighter airframe.  I'm rather hoping for tech transfer back to the V-22, yielding a V-22C with the same engine and prop-rotor set-up as the MV-75.

[apophenia]

Actually, now looking in from the outside, I believe the MV-75 uses the same engines as the MV-22B, but on a smaller and lighter airframe.  I'm rather hoping for tech transfer back to the V-22, yielding a V-22C with the same engine and prop-rotor set-up as the MV-75.

Thanks Evan. I read a bunch of statements people were making about relative power between the two types ... but none of them would ever say exactly which engine types were involved 

[GTX_Admin]

See here:  Bell Picks Rolls-Royce Engine for V-280 Valor in Army Black Hawk Replacement Contest

Both appear to be in the same 7000shp category though I suspect the AE1107F in the MV-75 benefits from some newer subcomponents (which may be retrofittable on the earlier AE1107C on the V-22) plus potentially some other mods given the setup on the MV-75 does not require the engines themselves to rotate.

[apophenia]

Thanks for that Greg 

[arc3371]

Great profiles and stories

[arc3371]

Seeing you PZL P51 I was wondering if you could give the Ikarus IK-2 the same treatment? That is replace the high wing configuration with a low wing preferably from the IK-3

[apophenia]

Seeing you PZL P51 I was wondering if you could give the Ikarus IK-2 the same treatment? That is replace the high wing configuration with a low wing preferably from the IK-3

Great idea! I dug around for some research and read that the IK-L1 prototype was originally planned to be a low-winged monoplane with a retractable main gear. I'd never seen that before!

[arc3371]

Seeing you PZL P51 I was wondering if you could give the Ikarus IK-2 the same treatment? That is replace the high wing configuration with a low wing preferably from the IK-3

Great idea! I dug around for some research and read that the IK-L1 prototype was originally planned to be a low-winged monoplane with a retractable main gear. I'd never seen that before!

Interesting, must admit that i never heard that the IK-1 was supposed to have a low wing

[apophenia]

... give the Ikarus IK-2 the same treatment? That is replace the high wing configuration with a low wing preferably from the IK-3

As promised ...

L for Lovački Avion - The Ikarus IK-L Series

The destruction of the prototype Ikarus IK-L1 on 24 April 1935 was a major blow to Yugoslav aviation but opinion on the type had raised strong emotions amongst the fighter pilots of the Jugoslovensko kraljevsko ratno vazduhoplovstvo (Royal Yugoslav Air Force). Many JKRV planners had pushed for an advanced monoplane type but serving pilots still preferred biplane fighters.

Among those who argued strongly in favour of biplane fighters was JKRV test pilot responsible for testing the IK-L1 prototype - Kapetan prve klase Leonid Bajdak. While testing the new fighter at Zemun, kap.VS Bajdak put the high-winged monoplane through a range of violent aerobatic manoeuvres. Having overstressed the prototype airframe, a portion of wing broke off. Bajdak then parachuted to safety as the IK-L1 fell to its doom.

If kap.VS Bajdak believed that his unauthorised aerobatics had secured him the biplane fighter he had demanded, he would be disappointed. The high-winged monoplane layout of the Ikarus IK-L1 had been chosen as a compromise meant to satisfy service pilots. With the demise of the IK-L1 prototype, it was decided to revert back to the original plan - which had been a fully-modern, low-winged monoplane with a retractable main undercarriage.

Back to 'Plan A' - The Low-Winged Monoplane

The French-trained designers of the IK-L1 - inž Ljubomir Ilić and Kosta Sivčev - returned to their drawing boards and revised their high-winged design into the new arrangement. Plans for all-metal construction were dropped (it having become obvious that skilled tradesmen in modern airframe techniques were rare in the Kingdom. Instead, the revised IK-L2 would have plywood-covered wooden wings and a steel-tube fuselage covered in alclad and fabric.

The rear fuselage was essentially identical to that of the lost IK-L1. The forward fuselage was revised to allow for wing mounting and to accommodate cowl guns raised to the uppermost fuselage (although no armament was installed in the prototype IK-L2). [1] First flown on 08 October 1936, the IK-L2 handled fairly well but the tail surfaces lacked authority. It was obvious that the prototype could benefit from a longer rear fuselage and, with that, it lost its remaining structural similarities with the IK-L1.

Top: The prototype Ikarus IK-L2 in its original, short-fuselaged form.

Ikarus Rises - The IK-L2 Into Production

By the time that the IK-L2 prototype was returned to the Ikarus assembly shed for its rear fuselage modifications, monoplane fighters - like the Polikarpov I-16, Fiat G.50, and Messerschmitt Bf 109 - were already flying. Accordingly, it was decided to launch into immediate production based on the design of the revised prototype. Other changes introduced were a stiffer tailplane (to eliminate bracing wires); a new, sliding cockpit canopy; and a Hydromatic propeller - the latter necessitating a re-profiling of the nose for the enlarged spinner. [2]

The first 'serija 1' IK-L2 Vetruška (Kestrel) was powered by a French 860 hp Hispano Suiza 12Ycrs engine and armed with 4 x FN Browning machine guns - 12.7 mm cowl guns and a pair of 7.92 mm guns in the wings. A dozen such aircraft were delivered by the end of 1939. The 'serija 2' fighters were identical other than standardising on four 12.7 mm FN guns. The 'serija 3' Vetruškas were a direct result of the fall of France and Belgium in 1940. Of necessity, substitute engines were sourced from German-occupied Bohemia-Moravia (in the form of 850 hp Avia-built HS 12Ydrs V12s). Armament was reduced to 4 x Czech 7.92 mm Letecky kulomet vz. 30 guns.

Bottom: A 'serija 3' IK-L2 Vetruška fighter assigned to the JKRV's 161.Eskadrilla, 51.Grupa in April 1941.

Prior to the 06 April 1941 invasion of Yugoslavia, IK-L2 Vetruška deliveries had slowed to a crawl due to wartime supply challenges. A planned 6-gunned 'serija 4' stalled when deliveries of Czech-built engines and machine guns ended. Likewise, the proposed IK-L3 powered by a German DB 601A progressed no further than a single IK-L2 'serija 1' conversion. Had the production Ikarus IK-L3 been realised, it would have been armed with twin synchronised 7.92 mm MG 17 cowl guns with a pair of 20 mm MG FF cannons mounted in the wings.

_________________________________

[1] Those raised cowl guns displaced the 20 mm autocannon planned for the IK-L1. It had proved difficult to get the French to commit to selling (or licensing) the new HS 404 moteur-canon and the Oerlikon FF alternative was less appealing to JKRV planners.

[2] The change was prompted by potential delays with French Ratier units. Hydromatic props could be sourced from De Havilland or, in the event of a wide-scale European war, from Hamilton-Standard in the US.

[apophenia]

A pair of Canadian Forces Cougar direct-fire support vehicles devised as fast-reaction vehicles for 4 Canadian Mechanized Brigade Group deployed to West Germany during the Cold War. [1] These Cougar DFSV were primarily meant to be on-road escorts for wheeled reinforcement columns moving forward.

Cougar DFSV armaments reflected their tracked equivalents - the Marder-based Marten C3s. [2] This resulted in the Cougar 30 (right) armed with a 30 mm RARDEN gun and the Cougar 40 (left) armed with a 40 mm Bofors gun. The 30 mm guns were late substitutes for the ordered Royal Ordnance L23A1 'pumpkin launchers'. The 40 mm guns were part of a refurbishment deal with Bofors for ex-BAOR L/70 anti-aircraft guns. [3]

______________________________________________________

[1] 4CMBG was a reserve formation meant to support NATO forces along the Czechoslovak border - either US VII Corps or West Germany's II. Korps (depending upon need).

[2] The tracked Marten C3B had the 40 mm Bofors gun in a KuKa turret while the Marten C3C was fitted with the 30 mm-armed Alvis turret.

[3] The bulk of the former British AA guns were used in a GBAD role at CFB Lahr and CFB Baden-Soellingen. Part of the Bofors refurbishment and modernisation process was fitting the L/70s with BOFI (Bofors Optronic Fire control Instrument).

[GTX_Admin]

 

[apophenia]

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?

___________________________

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 ...)

_____________________________


[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.

[apophenia]

Brock - The Bolingbroke Fighter (Part 2)

The nose of the pre-production Brock Mk.I had featured a beautifully-contoured blown Perspex windscreen. However, this windscreen and the smaller nosegap lacked any armour protection. As it became apparent that, over the North Atlantic, surface attack would be the major role, more protection from the increasing anti-aircraft armament of German U-Boats was required. This resulted in revised glasings incorporating armour glass panels for the full-production Brock Mk.II. [1] This armour glass solved a practical problem but did not address the fundamental flaw in the operational plan for RCAF Brocks.

It had been assumed that Brocks would be mainly employed in deterring and attacking German surface commerce raiders off of Canada's Atlantic coast. However, such Hilfskreuzers never appeared. Instead, the Brocks would be employed on anti-submarine patrols - a role for which they were viewed as inferior to the standard RCAF Bolingbroke recce-bombers. A partial redress was to reintroduce the rear bomb bays on the Brock Mk.IIa series with a plan to carry 2 x depth bombs.

Bottom: A Fairchild (Bristol) Brock Mk.IIa heavy fighter with No.118 (Fighter) Squadron RCAF at Dartmouth, NS, in the Spring of 1942. The obvious identification feature for the Brock Mk.II was the replacement of the dorsal turret with glazed panels (which were jettisonable in an emergency).

This Brock Mk.IIa has all its crew hatches open, ready for a mission. Light Series Stores Carriers are fitted with the forward carrier armed with Sea Markers. On the Mk.IIa, the rear bomb bays had been restored to operation. In the Spring of 1942, twin 250 lb GP bombs would have been carried (awaiting the availability of new 250 lb depth bombs).

Ad hoc Refinements - The Maturation of the Brock

In their occasional encounters with Brocks, U-boat crews came to respect these 'Rundnasen' (Round-Noses). The heavier forward-firing armament forced Uboat commanders to choose between being strafed on the surface or to be bombed while crash-diving. Unfortunately, just as the Brocks' effectiveness was being demonstrated, continued production of the type had come under threat. This was primarily because the Department of Munitions and Supply had allocated all imported Bristol Mercury engines to future Bolingbroke production. [2]

The RCAF belated recognised that, in comparison with the Bolingbroke, the Brock had advantages in both transit speed to patrol areas and, obviously, a heavier forward-firing armament. As a result, the search for an alternative powerplant was underway. Fairchild had already experimented with the American P&W R-1535 but, while acceptable for Bolingbroke trainers, an operational Brock fitted with these engines would be underpowered. The potential replacement engine options were, accordingly, reduced to either the Wright R-1820 or the P&W R-1830.

The Wright GR-1820-G3B was chosen to power the proposed Brock Mk.III. However, the RCAF preferred the P&W R-1830-S3C-4G Twin Wasp which powered the newly-arriving, Lend-Lease Lockheed Hudson Mk.V patrol aircraft. As a result, Brock Mk.III production was passed over in favour of the Pratt & Whitney-powered Mk.IV. The early production Brock Mk.IV was essentially similar to the Brock Mk.IIa other than its powerplants. These new engines were slightly narrower and longer than the single-row Bristol Mercury radials. This led to some loss of pilot visibility to the front-sides but slightly improved the view directly to the sides - helpful when winging over to bear down on a target at sea.

Top: A Fairchild (Bristol) Brock Mk.IV assigned to the Test and Development Flight at RCAF Station Rockcliffe, ON, in late 1942. This Twin Wasp-powered Brock Mk.IV has been partially upgraded to Mk.IVb standards - being fitted with a belly gun for strafing and a small dorsal strake to help balance the longer engine cowlings. However, most such upgrades lacked the propeller spinners' armoured back-plate featured by the production Brock Mk.IVb.

By the Autumn of 1942, Brock production had ended at Longueuil. During that time, newly-arriving Lockheed Venturas began replacing operational Brocks, Bolingbrokes, and Hudsons. Thereafter, all three types were diverted to training programmes.

(Fin)

_____________________________

[1]  The flat armour glass panel also served to reduce distortions inherent in curved perspex. The armour glass panels themselves were kept clear through direct heating and desiccation.

[2] The DMS was allowing for increased Bolingbroke production - especially for British Commonwealth Air Training Plan use.