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Affectionately nicknamed "Jug," the P-47 was one of the most
famous AAF fighter planes of World War II.
The Republic P-47 was the successor of a line of airplanes
derived from the Seversky P-35, the XP-41, P-43 Lancer, and
XP-44 Rocket.
The P-47 design team headed by Alexander Kartveli, Republic
Aircraft Corporation's chief engineer,
originally conceived the XP-47 as a lightweight interceptor,
powered by a 1,150 hp Allison V-1710-39 engine with
an armament of only two 0.50-inch machine guns. A
contract was awarded by the USAAC in November 1939, and for
an even lighter XP-47A, but as intelligence was coming back
from the war in Europe, it was becoming apparent that the
performance goals of the XP-47 program were already
inadequate. The USAAC issued new requirements that included:
airspeed of 400 mph at 25,000 feet, armament of six .50
caliber machine guns, preferably eight, and armor plating to
protect the pilot, self-sealing fuel tanks, and a minimum of
315 gallons of fuel.
Kartveli then quickly prepared a rough sketch of a
new XP-47B prototype, featuring a new 2,000 hp Pratt &
Whitney Double Wasp XR-2800-21, 18 cylinder, two-row radial
engine, (the most powerful aircraft engine at the time),
eight 0.50-inch machine guns, additional ammunition,
increased fuel capacity, armor protection for the pilot. The
XP-47 also featured and an efficient super-charging duct
system located in the tail, which made the system more
durable and less susceptible to battle damage. All these
features were costly in weight and the airplane would have a
take-off weight of 11,600 lb, which was more than twice the
weight of its contemporaries. Despite its size, the P-47
turned out to be one of the best three USAAF fighters of the
war—the other two being the North American P-51 Mustang and
the Lockheed P-38 Lightning.
A contract was awarded on 6 September 1940 for the new
XP-47B prototype and the maiden flight was only eight months
later on 6 May 1941 achieving a greater than expected speed
of 412 mph. An
initial order was placed by the USAAC for 171 P-47Bs and 602
P-47Cs. The P-47B
entered USAAF service in November 1942, becoming officially
operational in the European Theater with the Eighth Air
Force on 8 April 1943. However, the P-47B's range was not
adequate for escort duties, and its maneuverability at low
and medium altitude was poor. Since it was almost twice as
heavy as its opponents P-47s exhibited a poor rate of climb,
but had other advantages that more than compensated where it
was lacking. In spite of its early shortcomings, the P-47 at
least showed promise as a measure of real protection for
Allied bombers, which had previously suffered very heavy
losses.
The first tasks of the Thunderbolt were high-altitude escort
duties and fighter sweeps, in which the new aircraft
acquitted itself well, despite the inexperience of its
pilots. It was soon discovered that the heavy Thunderbolt
could out-dive any Luftwaffe fighter, or for that matter,
any Allied fighter, providing a decisive method of breaking
off combat when necessary, but at low and medium altitudes
it could not match the rate of climb or maneuverability of
German fighters. One main shortcoming was the lack of range
for deep penetration into Germany, to combat this 305 US
gallons of internal fuel was added to the P-47Bs.
By mid-1943, improved P-47Cs soon replaced the
P-47B on the production lines, incorporating the
most important changes required after experience with the
earlier model. Most importantly, the fabric-covered control
surfaces of the B were replaced by metal covered surfaces.
The P-47C was the first model of Thunderbolt to see active
service, going operational on 8 April 1943, and seeing its
first combat on 15 April. The P-47C featured external fuel
tanks to increase range and a longer fuselage to improve
maneuverability.
The P-47D was the major production version of which 12,602
were produced in 21 variants, Early P-47Ds looked very much
similar to early versions, up through the
P-47C with "razorback" fuselages, but later
P-47Ds featured a bubble canopy which gave the
pilot increased rearward visibility. In its initial form,
the P-47D differed very little from its predecessor P-47C.
It had some changes in the turbo-supercharger exhaust system
that incorporated an adjustable duct and redesigned vents
for the engine accessory section, additional cowl flaps for
better engine cooling airflow, and more extensive armor
protection for the pilot. However, early P-47Ds can be
distinguished from Cs only by serial numbers.
Demand for the P-47 was such that Republic built a new
factory at Evansville IN to augment production, 1,050 Evansville P-47Ds were
ordered on 31 January 1942, and the first one rolled off the assembly line in
Sep 1942 (42-2225). They were distinguished from Farmingdale-built P-47Ds by
their s/ns and an -RA manufacturer code replacing Republic's -RE. Following
cancellation of an Army contract for the P-60A in Jan 1942, Curtiss-Wright was
given a contract to build P-47Ds under license at its Buffalo plant—designated
P-47G and with -CU as a manufacturer code.
In Dec 1942, their first 20 P-47G-CUs
were similar to the P-47C, but the remainder, P-47G-1-CU through P-47G-15-CU,
was identical to Republic's P-47Ds, again distinguishable only by their serial
numbers.
Since Curtiss P-47Gs tended to lag behind Republic models in
the latest refinements, most were relegated to training
roles and very few went overseas. Curtiss production of 354
planes ended in March 1944.
P-47D-6-RE to P-47D-11-RE models came with an under fuselage
shackle for a 500 lb. bomb or a drop tank. Subsequent
models, up to the P-47D-20-RE, had strengthened wings with
under wing pylons and were able to carry a 1,000-pound bomb
under each wing. The "universal wing," which could carry a
variety of stores, was introduced with the P-47D-20-RE. A
large four-bladed "paddle" propeller was also fitted. This,
along with the water-injection R-2800-21 engine, which had a
war emergency rating of 2,300 hp, markedly improved the
maximum rate of climb, which was now up to 2,750 ft./min. at
5,000 ft. The P-47D-25-RE and subsequent models had a cut
down rear fuselage and a teardrop "bubble" canopy, adapted
from the British Typhoon fighter. Internal fuel capacity was
also increased. The R-2800-59 engine had a war emergency
rating of 2,535 hp. Climb rate was now up to 3,120 ft./min.,
and top speed was 426 mph at 30,000 ft.
The P-47M was the faster production version of the
Thunderbolt. That speed was achieved by using the Pratt &
Whitney R-2800-14W or R-2800-57 engine, with the CH-5
turbo-supercharger. At full boost this engine could provide
2,800hp, giving the P-47M a top speed of 473mph at 32,000
feet, an improvement of 50mph over the P-47D.and 130 P-47Ms
built with a 2,500 hp engine, giving a maximum speed of 473
mph. The P-47M version was used for anti
V1 Flying Bomb
duties.
The final model, the P-47N, had extended wings and an
additional 100 US gallons of fuel. It was developed too late
to see much action in Europe and was primarily used in the
Pacific theater. The fastest model was the XP-47J, which did
not go into production. On 4 August 1944, this plane reached
a level speed of 504 mph. Production plans were shelved in
favor of another P-47 development, the
Republic XP-72.
P-47s flew more than 546,000 combat sorties and almost 2
million flight hours between March 1943 and August 1945,
destroying 11,874 enemy aircraft, some 9,000 locomotives,
and about 6,000 armored vehicles and tanks. Only 0.7 per
cent of the fighters of this type dispatched against the
enemy were lost in combat. As a testament to the
survivability of the P-47, it should be noted that the top
ten aces who flew the P-47, returned home safely. Before the
war was over, a total of 15,579 Thunderbolts were built,
about two-thirds of which reached operational squadrons
overseas.
Between 22 September through 31 October 1943 the 325th
Fighter Group began a transition from the Curtiss P-40
Warhawk into the P-47. On 14 December, 325th Fighter Group
flew its first operational mission, an escort for four
groups of B-17s returning from a raid on the Kalamaki
Airdrome, Athens, Greece. By the end of the units P-47 era,
the Checkertail Clan flew 97 missions, 3,626 sorties, 15,280
combat hours, with 153 aerial victories, and 38 losses.
Later in the war, US Army Air Force Jugs served as escort
fighters for B-29 bombers in the Pacific. Mostly, though,
they excelled in the ground-attack role, strafing and
bombing their way across the battlefields of Europe. P-47s
were also used during the war by the air forces of Brazil,
England, France, Mexico, and the Soviet Union. Following the
war, the Jug served for nine more years in the US, flown by
the Air National Guard. It continued to serve for many
additional years with the air forces of over 15 nations
around the world.
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