A product of John
Northrop's influence on Douglas design philosophy, the Dauntless
stemmed from the Northrop BT-1 which began to enter service with the US
Navy in spring 1938. One of the production BT-1s served as the
prototype for a new naval dive-bomber, allocated the designation XBT-2,
however, by the time that this entered production in 1940, Northrop had
become a division of the Douglas Company, resulting in the SBD
designation to identify Douglas as the manufacturer of the new
scout/dive-bomber.
There had been
structural and engine changes, and while the SBD retained a general
family likeness to its progenitor, it was really a very different
aeroplane. Of low-wing cantilever configuration, it was of all-metal
construction except for fabric-covered control surfaces. Features of
the wing design included slots adjacent to the leading edge forward of
the ailerons, and hydraulically actuated perforated dive-brakes above
and below the trailing edge of the wing outboard to the ailerons, and
below the wing centre-section and beneath the fuselage. Fuselage
construction included a number of watertight compartments, the tail
unit was conventional, and the main units of the tailwheel type landing
gear retracted inward to lie flush within wells formed in the wing
centre-section. Arrester gear was provided for shipboard operation.
Accommodation was provided for a crew of two in tandem cockpits, housed
beneath a continuous transparent canopy, and provided with dual
controls. The powerplant of the prototype was a 1,000 hp (746 kW)
Wright XR-1820-32 Cyclone radial engine.
Testing of the
prototype showed not only its superiority over the earlier Northrop
BT-1, but performance and flight characteristics that immediately
singled it out as an exceptional aircraft. Initial production orders
for 57 SBD-1s and 87 SBD-2s were placed on 8 April 1939, the SBD-2s
differing by having increased fuel capacity and armament revisions.
SBD-1s began to enter service with the US Marine Corps in late 1940,
equipping Marine Squadron VMB-2, with deliveries to VMB-1 following in
early 1941. The SBD-2s went to the US Navy, and by the end of 1941 were
serving aboard the USS Enterprise with Squadron VB-6, and with VB-2 on
the USS Lexington.
An improved SBD-3
version began to enter service in March 1941, introducing self-sealing
tanks (and with increased fuel capacity), armour protection,
bullet-proof windscreen, a 1,000 hp (746 kW) Wright R-1820-52 engine,
and armament changes that initiated the standard of two 12.7 mm (0.50
in) and two 7.62 mm (0.30 in) machine guns. The SBD-3 was followed into
production by the SBD-4, which differed only by having a 24-volt
instead of 12-volt electrical system. Production of these two versions
totalled 1,364 units, making possible a wider distribution of these
much needed and important aircraft to US Navy squadrons which included
VB-3, VB-5, VS-2, VS-3, VS-5 and VS-6, as well as to many US Marine
Corps squadrons.
Most extensively built
was the SBD-5, produced in a new Douglas factory at Tulsa, Oklahoma.
This differed from earlier versions in having a 1,200 hp (895 kW)
R-1820-60 engine and increased ammunition capacity as well as
introducing illuminated gunsights for both the ; fixed forward-firing
and rear cockpit flexibly-mounted machine-guns. A total of 2,409 were
built for the US Navy before Douglas turned to the final production
variant, the SBD-6, with an even more powerful R-1820-66 engine and
increased fuel tankage. Also supplied to the US Navy in small numbers
were photo-reconnaissance variants of the earlier production versions,
with camera installations and related equipment, under the designations
SBD-1P, SBD-2P and SBD-3P. Nine examples of the SBD-5 version were
supplied for service with the Royal Navy's Fleet Air Arm in January
1945, these being designated Dauntless DB Mk I, but none of them was
used operationally. Another small quantity was supplied to Mexico.
Although the US Navy and US Marine Corps use of the Dauntless in a
first-line capacity tailed off in late 1944, many late-version aircraft
remained in use for some years after the end of World War II.
A Douglas SBD-5 V.C.40 US Navy Air Force - Torokina, Bougainville, New
Guinea April 1944
The success of the
German Junkers Ju 87 as a dive-bomber, when Hitler's armoured columns
raced over much of Europe in 1940, made the US Army conscious of the
fact that it possessed no significant aircraft within this category.
Accordingly 168 of the US Navy's SBD-3 version were ordered from
Douglas as a matter of some urgency, these being delivered in the
summer of 1941 under the US Army designation A-24. They were virtually
identical to the SBD-3, except for the deletion of the arrester hook,
and the provision of an inflated tailwheel tyre instead of the solid
rubber favoured by the US Navy. About a third of these aircraft were
despatched to the Philippines in November 1941 for service with the
USAAF's 27th Bombardment Group, but as they were still at sea when
Pearl Harbour was attacked, they were diverted instead to Australia,
equipping the 91st Bombardment Squadron in February 1942, and
subsequently the 8th Bombardment Squadron. Both of these units found
the A-24 lacking in performance and range for operational deployment in
this theatre.
Despite these apparent
shortcomings, the US Army continued to procure A-24s during 1942,
receiving first 170 A-24As (equivalent to the US Navy's SBD-4), and
finally 615 A-24Bs (SBD-5). None were deployed with significant
success, confirming the experience of Ju 87 usage in Europe and Africa,
that their role was strictly confined and within that limited role, of
course, they were indeed the 'tool for the job'. Their failure in US
Army service was due to the fact that there was no identical job for
them to do. Despite this, a number remained in USAAF/USAF service for
some years after the end of World War II.
Nicknames:
Barge; Clunk; Speedy-D; Speedy-3;
Slow But Deadly; Banshee (A-24).
Specifications (SBD-6):
Engine: One 1,350-hp Wright
R-1820-66 Cyclone 9-cylinder radial piston engine
Weight: Empty 6,535 lbs.,
Max Takeoff 9,519 lbs.
Wing Span: 41ft. 6in.
Length: 33ft. 0in.
Height: 12ft. 11in.
Performance:
Maximum Speed: 255 mph
Cruising Speed: 185 mph
Ceiling: 25,200 ft.
Range: 773 miles
Armament:
Two forward firing 12.7-mm
(0.5-inch) machine guns;
Two 7.62-mm (0.3-inch) machine
guns on flexible mounts;
Under-fuselage mountings for up to
1,600 pounds of bombs;
Wing hardpoints for up to 650
pounds of bombs.
Number Built:
5,936
Number Still Airworthy:
3 |