The Bureau of Aeronautics struggled to find surplus production capability for the US Navy's Douglas-designed TB2D-1 shipboard torpedo bomber. The XTB2D-1 was based on the A-20G Havoc airframe but Douglas was phasing out A-20 production at its El Segundo plant in favour of the new A-26 Invader. An enquiry to Boeing paid off. Before the end of 1944, Boeing Aircraft Canada Ltd (BACL) was scheduled to have delivered its final production PB2B-2 flying boat to the USN (the last Catalina VIB to British contracts having already been completed).
Boeing Canada was scheduled to replace flying boat production with the building B-29 fuselage centre sections for its parent company. Instead, it was arranged that BACL take on Havoc production. This plan could be brought to fruition quite quickly since Boeing held tooling for the A-20 in storage outside Seattle. [1] It was arranged for jigs and tooling to be shipped north to BACL's Plant 3 on Sea Island, BC.
Initial BACL production would be for A-20L Havocs - roughly equivalent to the in-service A-20K and RAF Boston Mk Vs. Compared with A-20Ks, these R-2600-29-powered aircraft were hybrids - retained some early-model A-20C features and having the capability to carry both US and British aerial torpedoes. No A-20Ls were ever delivered to US forces. Instead, all A-20Ls were provided to allies through Lend-Lease. The RAF was scheduled to receive the first Boston TB Mk VIs but Coastal Command preferred its Bristol Beaufighter TF.Xs.
There was no prototype Boston TB Mk VI but the first aircraft was retained by BACL for test use. The next dozen Boston TB Mk VIs went to the RAF but stayed in British Columbia. These Mk VIs replaced ancient Hampden TB Mk Is used for training by No.32 OTU (RAF) at Patricia Bay on Vancouver Island. The Boston TB Mk VI was a three-seater fitted with US-supplied perspex nose caps. Fixed armament consisted to twin forward-firing 0.50-inch Browning machineguns with another pair of 'Fifties' in a Martin dorsal turret. The 18-inch Mk XII torpedo was used for training at No.32 OTU. [2]
(Top) First production Boeing Canada Boston TB Mk VI (107850) with BACL Boston Test Unit badge on its nose. Note that only the first aircraft had the enlarged, squared-off elevators (which were found to be unnecessary).
Other than No.32 OTU, BACL Bostons were surplus to British needs. Later Bostons were diverted for use by RCAF Western Air Command. These were all 2-seat Boston TB Mk VIAs which had 'solid' noses armed with eight 0.50-inch Brownings. The TB Mk VIA retained its torpedo lugs but there is no record of operational RCAF Boston TB Mk VIAs carrying torpedoes. Assigned to No.8 (BR) Squadron at Sea Island, the RCAF TB Mk VIAs flew patrol missions. Schemes to produce dual-control trainer model Boston T Mk VIBs and cannon-armed TB Mk VICs were eclipsed by the pressing need for carrier torpedo bombers for the impending invasion of the Japanese home islands.
Boeing Canada T2B-1 for the US Navy
'Productionizing' the Douglas-designed shipboard torpedo bomber took longer. The first Sea Island-built T2B-1 was not delivered to the US Navy until July 1945. The T2B-1 was virtually identical to Douglas' XTB2D-1 prototype other than incorporating some Boston TB Mk VI components. The first T2B-1 was deliver to NAS Seattle at Sand Point Airfield where VT-70 had been formed to operate these shipboard torpedo bombers. Actual training of VT-70 took place at NAS Whidbey Island - first on A-20J Havocs on loan from the USAAF, then on actual T2B-1s as they arrived from British Columbia.
Plans were underway to develop a more advanced version - the T2B-2. This variant differed in having a more advanced defensive armament system. The T2B-1's Martin dorsal turret was to be replaced by a remotely-operated General Electric system based on that of the A-26 Invader. In place of the Invader's twin GE turrets, the T2B-2 would have only the dorsal components. The Central Fire Control System was adjusted to compensate for the 'halved' GE Mark 33 gunsight (employing only the upper half of the Invader sight). An order was placed for an XT2B-2 prototype to demonstrate the remotely-operated armament system.
T2B-1 production was proceeding slowly when the Pacific War ended in mid-August 1945. Remaining production orders for the A-20J Havoc were cut by the end of the month. US Navy contracts for the T2B-1 were cut in September 1945 as was the development contract for a prototype XT2B-2 meant to demonstrate the more advanced defensive armament system. A final dozen semi-completed T2B-1s were delivered to the US Navy but went almost immediately into storage before scrapping. And that seemed to be the end of the Boeing Canada Havoc story.
All production contracts for Boeing Canada-built A-20L Havocs [3] were cancelled in late August 1945. As Lend-Lease aircraft, all RCAF Boston TB Mk VIAs were to be returned to the US (where most would be scrapped before the year was out). Contracts for USN T2B-1s were amended in Sept 1945 while the development contracts for the XT2B-2 prototype were cancelled outright. Twenty near-completed T2B-1s were finished and delivered to the US Navy by the end of Oct 1945. Those aircraft went directly into storage and the career of the 'Sea Havocs' seemed to be at an end.
Post-WW2 Use of the Boeing Canada 'TBs'
With the end of the Lend-Lease arrangement, the RCAF lost most of its land-based maritime patrol capability - not only the Boston TB Mk VIAs had to be returned but also those Lockheed Venturas and Consolidated Liberators which Canada was unwilling to pay for. In the heady days immediately following the end of the war, most of the RCAF patrol fleet was eliminated. Boeing Canada was also at a loss with the completion or cancellation of all of its production contracts. BACL was also left with large stocks of semi-completed T2B-1 components. In early 1946, Boeing proposed that the most complete 'Sea Havocs' be finished as RCAF maritime patrol aircraft.
The first Boeing Boreal Mk.1MR for the RCAF was a hybrid of Boston VI and T2B-1 features. The fixed wings were those of the Boston, while the fuselage was based on that of the carrier aircraft. The forward fuselage fuel tank of the T2B-1 was eliminated, allowing a third crew position directly behind the pilot. That third crew member operated the ASV (Air-to-Surface-Vessel) radar - a US AN/APS-3 (ASD-1) set. The radar radome was retractable - occupying, when retracted, what would have been the forward section of a Boston's bomb-bay.
The Boreal Mk.1MR were assigned to the newly-formed No.407 (Maritime Reconnaissance) Squadron based at Comox, BC. [4] Later, the terminology would be changed to 'Maritime Patrol' and the Boeings were redesignated Boreal Mk.1MP. The aircraft performed well but were really too cramped for the maritime patrol role. Despite this rather serious limitation, a naval variant of the Boreal was also devised for use by the Royal Canadian Navy.
The Boeing Boreal Mk.2 for the RCN was essentially the same as the RCAF Mk.1 but re-introduced the folding wings of the T2B-1 and featured ASW equipment. This included a retractable MAD 'stinger' in the tailcone and extended nacelles with aft-launched sonobuoys. Like the RCAF Boreal Mk.1, the Navy's Mk.2 were equipped as maritime patrol aircraft. However, the Boreal Mk.2 had catapult lugs allowing it to operate from aircraft carriers. At that point, the RCN's shipboard ASW requirement was being fulfilled by its Grumman Avengers and the Navy saw no need for twin-engined carrier aircraft.
The Boreal Mk.2A was a short-term conversion fitted with the Avenger's lightweight AN/APS-4 (ASH) radar. Although slight, that ASV's performance loss was deemed unacceptable and benefits were marginal. With the ASD-1 set re-installed, the test aircraft was returned to Mk.2 standard.
(Bottom) Boeing Boreal Mk.2 of FRU 745 at Shearwater, Nova Scotia. Note the retracted ASD-1 radar and disabled Martin turret used as an observation cupola. For some reason, '465' has had its retractable MAD tail boom removed.
The Boreal Mk.2 flew with two RCN Fleet Requirement Unit squadrons - FRU 743 at Dartmouth, NS and, later, FRU 745 at Shearwater, NS. The Fleet Requirement Units were composite squadrons with the Boreals operating alongside the preferred, single-engined Avengers. With the Boreals, the RCN found itself flying similar aircraft to the RCAF in an identical role. In a unique division of labour, the RCN Boreal Mk.2s flew medium-range maritime patrol missions off the East Coast, while RCAF Boreal Mk.1MP were their West Coast counterparts - with detachments flying from Prince Rupert and Sea Island before being moved to RCAF Station Comox.
The Boeing Boreal was really too cramped for its patrol role. RCAF crews preferred the more capacious Lancaster 10MR while RCN crews want out of 'landman' operations altogether. The Navy crews got their wish in the RCN's 1951 re-organization of its air assets. The Navy's Boreal Mk.2s were passed on to the RCAF to back up the Boreal Mk.1 fleet. Most of the Mk.2s were stripped of useable spares (and employed as ground instructional airframes). Even so, the RCAF Boreals were living on borrowed time.
No.407 (MR) Squadron had initially fallen under Western Air Command. When WAC was disbanded in March 1947, No.407 (MP) came under 12 Wing (Comox) of North Western Air Command. NWAC was itself disbanded in August 1951 and, in the re-organization, No.407 (MP) Squadron gave up its Boreals. There were a range of replacement plans [5] but, in a final indignity, the Boreals were replaced by Beech Expeditors.
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[1] At the Seattle plant, Boeing had built 165 x Boston Mk.IIIA for the RAF and another 139 x A-20C-BO Havocs.
[2] There was provision for twin wing racks (for 500 lb GP bombs) but these were never fitted to TB Mk VIs.
[3] With RCAF requirements satisfied, it was planned to divert future A-20L-BOs to the Soviet Union via Alaska.
[4] No.407 (MR) initially fell under Western Air Command. When WAC was disbanded in March 1947, No.407 (MP) came under 12 Wing (Comox) of North Western Air Command
[5] One unrealized RCAF plan was to re-equip No.407 (MP) with North American Mitchell Mk.IIs and IIIs. Alas, the RCAF brass regarded VIP Mitchells as sacrosanct and there were insufficient aircraft in the photographic sections and auxiliary squadrons to replace the Boreals.