Hawker HURRICANE Mk II B
Design of the
Hurricane had begun in 1934, and its first flight had been made, from
Hawker's establishment within the confines of the historic Brooklands
motor racing circuit at Weybridge in Surrey, on November 6, 1935. Sydney
Camm's design team at nearby Kingston upon Thames already had long
experience of fighter design for the RAF, and drew heavily upon this
experience to produce what was at first seen as a "Monoplane Fury" --
the Fury being the elegant biplane that still epitomized the equipment
of Fighter Command upon its formation within the RAF in, July 1936, Such
advanced features
as an enclosed cockpit and retractable
undercarriage were combined with traditional methods of construction
using a tubular metal structure and fabric covering, that meant that the
Hurricane could be easily and rapidly produced in existing facilities --
an advantage not enjoyed by the Spitfire with its advanced stressed-skin
construction and complex shapes.
In February 1936,
the prototype Hurricane (as yet unnamed), powered by an early Merlin C
producing 900hp and driving a Watts fixed-pitch two-bladed wooden
propeller, was tested at the Aircraft and Armament Experimental
Establishment (A & AEE) at Martlesham Heath, giving Service pilots their
first opportunity to experience the improvements in performance and
handling that were to become available.
At a weight of
5,6721b (2,572kg), the prototype demonstrated a speed of 315mph
(506km/h) at the Merlin's rated altitude of 16,200ft (4, 937m)with 61b/sq
in boost, After taking off into a 5mph (8km/h) wind with a run of 795ft
(242m) to reach the 81mph (180km/h) lift-off speed, the Hurricane
climbed to 15,000ft (4,570m) in 5.7 minutes and to 20,000ft (6,100m) in
8.4 min. Service ceiling was 34,500ft (10,515m) and the estimated
absolute ceiling was 35,400ft (10,800m).
Convinced that the
RAF would buy the new fighter in the prevailing mood of rearmament, the
Hawker company decided, in March 1936, to proceed with the production
drawings and to make plans for large scale production. Three months
later in July, that action was vindicated when the Air Ministry
confirmed that 600 Hurricanes were to be included in its expansion Plan
F (which also provided for 300 Spitfires). By the time the Battle of
Britain began, every single fighter in the hands of the RAF counted, and
the early launch of Hurricane production had helped to ensure that just
enough machines were in fact available to Fighter Command.
Even so! meeting
the RAF's rapidly expanding needs proved to be no simple matter and the
Plan F target of 600 Hurricanes to be delivered bv March 1939 was missed
by some six months. There had been a succession of relatively minor but
time consuming problems with prototype development, especially related
to the Merlin, and the early intention to fit the Merlin F (Mk I) in the
production Hurricane was changed to make use of the improved Merlin G; (Mk
II)- which required a redesign of the installation and the front
fuselage profile before production could begin. The cockpit canopy also
produced its share of problems, with five failures recorded on the
prototype before a satisfactory design was evolved.
The first
production Hurricane I flew at Brooklands on October 12th 1937, fitted
with an early example of the Rolls Royce Merlin II that was rated at
1.030 hp at 16,250 feet (4,955m). This power unit drove a fixed pitch
two bladed propellor and at a weight of 5,459lb (2,476kg) the aircraft
attained a maximum speed of 318 mph (512 kph) at 17,400 feet (5,305m).
In January 1939,
the Merlin II gave way to the Merlin III and with the fitting of a
constant speed three bladed propellor and it was this amended
specifications that was adopted and all Hurricane Mark I's were
constructed using this configuration. Other alterations/additions being
the armament which was four Browning .303 machine guns mounted in the
wings, metal stressed- skin covered the wings instead of fabric which
also covered the fuselage.
By the 27th
September 1939, Hawker had delivered 497 Hurricanes to the RAF against
the initial order of 3,500 and was enough to equip 18 Fighter Command
squadrons. But despite the need to bring Britain's fighter strength to
its potential, quite a number of Hurricanes were exported to other
countries. 15 went to Turkey, another 15 went to Finland, 12 went to
Romania while 1 went to Poland.
During late 1939
and early 1940, 1,924 Hurricanes had been constructed by the Hawker
works while Gloster Aircraft who also took on construction built 1,850.
Hawker also put out tenders for the construction of the Hurricane
overseas. One of these successful tenderer's was the Canadian Car and
Foundry Works (CCF) and a licence was issued for the construction of
both the Hurricane and the Sea Hurricane. A total of 1,451 machines were
built and of these, 60 were flying by 10th January 1940. The Canadian
company built the Hurricane in a number of different versions. The
original accepted design of the Mark I, the Mark X which were powered by
the Merlin 28 engine and built by the Packard Car Co, the Mark XI which
was built with Canadian equipment and the Mark XII's that now
incorporated the Merlin 29 engine and 12 Browning guns. (8 guns in the
Mark XIIA).
Because of the
weather conditions in Canada and especially Nova Scotia where many of
them were based, the normal retractable undercarriage was dispensed with
and fixed ski's were used in there place. This allowed the aircraft to
take off and land on snow and ice.
During 1939 and
1940, 24 Hurricane Mark I's were delivered to Yugoslavia, and Belgium
was also granted a licence to build the fighter although 20 had been
acquired from Britain only 15 of these had been delivered.
Hurricane Mark II through to Mark V
June 11th 1940 a
Hurricane Mark I was fitted with a two stage supercharged Rolls Royce
Merlin XX engine that at sea level was rated at 1,300hp rising to
1,460hp at 6,250 feet. After numerous tests the aircraft was given the
designation of Mark II, the improved power plant being the only
difference from the Mark I. This first model of the MkII was known as
the Series I. Further modifications took place as designers tried to
make improvements to the Hurricane. The next model was given the title
of Mark II Series 2. The fuselage was given added strengthening which
was needed to accommodate the redesigned wings that incorporated
attachment points for external stores. A bay was also introduced into
the fuselage that also increased the length by a additional 7 inches
(7.7mm).
In November 1940,
the Mark II Series 2 was given additional firepower by the inclusion of
12 .303 machine guns mounted in the wings. This version was known as the
Hurricane IIB.
The Hurricane IIC
followed by having four 20mm Hispano cannons also mounted in the wings.
Many of these versions flew during the Battle of Britain with a number of Mark II's being fitted with drop-tanks, some being fitted with light to medium bombs while other had increased stores such as additional room for bullets for the machine guns.
After the Battle of
Britain, the Hurricane was further developed, mostly up to and including
1942 even though it was relieved as a front line attack aircraft in the
air to air war, and was used mainly as a ground attack aircraft. The
Mark IIC served until June 1942 when the Hurricane IID appeared which
was basically a IIC but with two 40mm cannons and two .303 machine guns.
The Hurricane II
gave way to the Hurricane III with a Packard Merlin power plant, then
came the Hurricane IV, the first prototype flying on 14th March 1943
which had been previously known as the Hurricane IIE, but after the
designation change was fitted with reinforced under wing attachments to
carry bombs and rockets and was given the new Merlin 24 engines that put
out 1,620hp. A further alteration saw the Mk V which was a Mk IV but
given even more power by the fitting of the 1,700hp Merlin 32 engines
and having four bladed propellors.
In all, 8,406
Hurricane II's were produced, with 3,000 going to the Soviet Union. In
all, only 794 Hurricane IV's were made.
In conclusion, the Hurricane was a fighting plane that pilots agreed would be having a great future. At the time when the first prototype took to the skies, it had performance not yet seen in combat aircraft. Many were, even in the mid-thirties, were looking towards the Spitfire which was already in prototype stages and being based on earlier designs that had won the Schnieder Trophy race and it looked as if it was a race to see what aircraft would be first in production. But the Spitfire was taking longer to produce
in the early stages, and it was the Hurricane that entered service first.
In the hands of a skilled pilot, the Hurricane could achieve great success. In fact during the Battle of Britain between July and October 1940, 1.720 of them took part and had the honour of claiming 80% of enemy aircraft shot down by Fighter Command.
The Hurricane's
performance was increasing all the time. It was believed that if the
Battle of Britain had continued longer, the performance difference
between the Mk IIA and the Bf109 was constantly being reduced. Had the
Mk II's been powered by the Merlin 32's during the Battle of Britain,
then many feel sure that it would have been a certain match for the
Bf109.
MORE ABOUT IT
As expected
the first Mk.I production machines were ready fairly quickly, and
deliveries started in October 1937. They mounted the 1,030 hp (768 kW)
Rolls Royce
Merlin Mk.II or
III engine and were armed with eight
.303-in Browning
machine guns. These early planes were rather simple, with fabric-covered
wings, a wooden fixed-pitch propeller, and without armour or
self-sealing tanks.
These issues were addressed in 1939. The new Mk.I included a deHavilland or Rotol constant-speed metal propeller, ejector exhaust stacks for added thrust, metal-covered wings, armour and other changes. At the start of the war the RAF had taken on about 500 of this later design, and it formed the backbone of the fighter squadrons during the Battle of France and into the Battle of Britain. Although it may have been an older design, the Hurricane was still a worthy fighter on its own and a reasonable match for the Messerschmitt Bf 109 it faced. Much of this was the result of the use of the very impressive Rolls Royce Merlin engine, which also powered the Spitfire. The Merlin (using 100 octane fuel) gave more power at low altitude than the Daimler-Benz DB 601 used in the Bf 109. Above 15000 ft, the DB601A-1 had the edge on the Merlin III and XII, though. During the Battle of Britain the Hurricane accounted for the majority of the planes shot down by the RAF, being vectored against the slower bombers whilst the Spitfires kept the defending German fighters occupied, but their day was already over. By the close of the Battle of Britain in late 1940, production of the Spitfire had ramped up to the point where all squadrons could be supplied with new machines. Deliveries of the Spitfire were now outpacing the Hurricane, as it turned out that its all metal construction allowed it to be produced even faster than the mixed-construction Hurricane. Hurricane Mk.IIRolls-Royce was improving the Merlin even before the war started, and in 1940 started production of the Merlin XX (Mk.20). The XX featured a new two-speed supercharger, that could have its impeller-speed changed by the pilot depending on the outside air pressure (altitude). At about 18,000ft (effective) it would be switched to a higher-speed gearing ("FS ratio" — Full Supercharge) for added compression, while below that, at its lower-speed gearing, ("MS ratio" - Moderate Supercharge) it "robbed" less power from the engine. The result was more power at both lower and higher altitudes, dramatically increasing overall performance of the engine, peaking at 1,280hp (954 kW). Although by this time production of the Spitfire had started to ramp up, a Merlin XX powered Hurricane Mk.I was built and first flew on 11 June 1940. The initial Mark II, retroactively to be known as the Mark IIA Series 1, went into squadron service in September 1940 at the peak of the Battle of Britain. Hawker had long experimented with improving the armament of the fighter by fitting cannon. Their first experiments used two Oerlikon 20mm anti-aircraft cannons in pods, one under each wing, but the wooden wings were deemed to fragile to handle the large and somewhat temperamental fitting. A more reasonable fit was made with four Hispano Mk.II 20mm cannons, two in each wing, but the weight was enough to seriously impact performance. Fitting the cannons also proved to be a problem, as the cannon was designed to be drum fed and fired through the propeller shaft, and a suitable belt-feed mechanism hadn't yet been worked out. With the new Merlin XX, performance was good enough to keep the aging Hurricane in production. Hawker soon introduced the new Mark IIA Series 2 with either of two wings, one mounting twelve Brownings, the other four Hispano cannon. The first Series 2's arrived in October, also sporting a new and slightly longer propeller spinner. These were later to become the Mark IIB in April 1941 and Mark IIC in June, respectively, using a slightly modified wing. The Mk.IIC used drums for the cannons to avoid the problems with the earlier attempts and belt feeds, limiting their ammunition. The new wings also included a hardpoint for a 500 lb or 250 lb bomb, and later in 1941, fuel tanks. By this point the design was falling well behind the latest German fighters in terms of performance, and the Hurricane was re-tasked in the fighter-bomber role, sometimes referred to as the Hurribomber. Mk.IIs were used in the ground support role, where it was quickly learned that destroying German tanks was terribly difficult; the cannons didn't have the performance needed, while bombing them was almost impossible. The solution was to equip the plane with a 40mm cannon in a pod under each wing, reducing the other armament to a single Browning in each wing for spotting. The layout was originally tested on a converted Mk.IIB, and flew on 18 September 1941. New-build version of what was known as the Mk.IID started in 1942, including additional armor for the pilot, radiator, and engine. The planes were initially supplied with a Rolls-Royce gun with 12 rounds, but soon upgraded to the Vickers S gun with 15 rounds. Yet another wing modification was introduced in the Mk.IIE, but the changes soon became extensive enough that it was renamed the Mk.IV after the first 250 had been delivered. Hurricane Mk.IIIThe Mk.III was a Mk.II equipped with a Packard-built Merlin engine, intending to free up supplies of the British-built engines for other designs. By the time production was to have started, Merlin production had increased to the point where the idea was abandoned. Hurricane Mk.IVThe last major update to the Hurricane was to "rationalize" the wing, equipping it with a single design able to mount two bombs, two 40mm guns or eight "60 pounder" rockets. The new design also mounted the upgraded Merlin 24 or 27 equipped with dust filters for desert work, delivering 1,620 hp (1,208 kW). Hurricane Mk.VTwo Hurricane "Mark Vs" were built as conversions of Mark IVs, and featured a Merlin 32 engine driving a four-bladed propeller. As the ground-attack role moved to the more capable Hawker Typhoon, production of the Hurricane instead ended, and only a handful were delivered with the Merlin 32. By this time, the Hurricane was no longer equipping frontline fighter squadrons in the United Kingdom itself. However, it still saw extensive service overseas in the fighter role, playing a prominent role in the Middle East and Far East. It was also critical to the defence of Malta, helping to see the island through some of its darkest days. |
