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P-47
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- Written by Super User
While much of the romance of World War 2
dogfighting often heads in the direction of
the USAAF's North American P-51 Mustang
or the Vought F4U Corsair, the Republic
P-47 Thunderbolt (affectionately
nicknamed "the Jug" by her pilots) stands
second to none when considering her
global reach, her contributions to the air
and ground war (in all theaters) and the
fact that she was produced more than any
other American fighter of the war.
Though not too pretty to look at, the
Thunderbolt had "it" where it counted -
through her stressed metal skin, robust
airframe and powerful engine. Her weight never made her a prominent close-up
dogfighting champion but this drawback allowed her to excel in "dive and zoom"
attacks against enemy fighters while proving her equally adept at ground strikes
accomplished through the battery of eight heavy machine guns, 5-inch rockets and
conventional bombs. In the end, this unsung hero of World War 2 proved that she
played second fiddle to no one - regardless how sexy a design she was up against.
The P-47 proved such a fearsome foe that Axis infantrymen on the ground dreaded
the day they would have to encounter the "Fatty from Farmingdale" coming out of the
skies with her eight machine guns ablaze. The Thunderbolt served in every major
combat theater of World War 2.
This article if for all those Jug pilots that never got their due.
Alexander de Seversky
Alexander Nikolaivitch Prokofiev de Seversky was born into a wealthy aristocratic
family back in Russia. Though thousands of miles away from any American city, this
family name would help to one day bring about the creation of the fabled P-47. As no
one thing was out of reach for such a family, one of the prizes under Seversky
ownership became one of the first airplanes in the country of Russia. As such,
Alexander Seversky learned to fly at an early age and a passion for all things flight
and an equal passion for all things mechanical soon evolved from within. Seversky
was then enrolled in military school by age 10 and went on to graduate from the
Russian Imperial Naval Academy in 1914. By the time of World War 1, he was
stationed aboard a destroyer as a sailor with the Russian Navy in the Baltic Sea but
his first passion remained flying - and he was quite good at it. Shortly after 1915, he
transferred out of the Navy and attended the Military School of Aeronautics only to
return to the Russian Navy - this time as a pilot.
After his re-assignment, Seversky was installed into one of Russia's burgeoning flying
squadrons. He was charged as pilot of a two-man bombers with a comrade - the
observer/rear gunner - in the second cockpit. Seversky took to the air in what may
have felt like a "routine" (if there's anything routine about combat) mission against
German destroyers. During the initial attack, his aircraft took serious ground fire,
foiling the attack and forcing the aircraft into the sea. To add insult to this mishap, the
unexploded ordnance under the wings now detonated, instantly killing his observer
and severely mutilating Seversky's leg. While eventually rescued, Russian doctors
were forced to amputate the damage leg and Seversky's flying career was all but
over.
Recovered from his wounds and now fitted with a wooden leg, Seversky set out to
reclaim his former position as a flyer with the Russian air service. While his superiors
balked at such a notion, Seversky illegally took to the skies in an aircraft during an
aerial exhibition complete with high ranking Russian military officials in attendance.
While his airborne actions proved him a sound pilot still, Seversky was promptly
incarcerated for his actions but later pardoned by Czar Nicholas II. Seversky was then
granted his flight status once more and was airborne in 1916. From there, Alexander
Seversky went on to become the Russian Navy's leading combat ace, accruing
somewhere between 6 to 13 kills (sources vary widely on this account). Leg or no leg,
Seversky was going to fly as long as his heart was beating.
This is Pure Bolshevik!
In 1917, Seversky was part of an envoy sent to the United States to study
aeronautical practices and construction techniques throughout the country. America
was home to the assembly line and it seemed the perfect place for any developing
industrial powerhouse to take notes. However, 1918 saw Russia fall to the Bolsheviks,
putting Seversky - with his wealthy aristocracy origins - in jeopardy and dissolved any
notion of returning safely to his motherland. As such, he elected to remain in the
United States where his combat background and engineering talents were put to use
with Curtiss Aeroplane. Seversky served as both test pilot and aeronautical engineer
for the firm eventually having his hard work rewarded by a promotion to Major in the
US Army Air Corps Reserve.
An entrepreneur at heart, Seversky was quick to protect his innovations when it came
to aircraft development. While securing a patent for an early air-to-air refueling
technique, he also made headway in the development of a bombsight system which
he developed with help from the Sperry Gyroscope Company, also netting Seversky a
patent to protect this work. The US military purchased the rights to the bombsight
system in 1923 for the large sum of $50,000 and this proved a sound financial ground
for which Seversky could begin his own company - aptly named the Seversky Aero
Company. However, the financial Crash of 1929 did this first venture in.
Undeterred, Seversky persevered and, netting additional funding from outside parties,
began Seversky Aircraft in 1931. He tapped former fellow Russian (Georgian) engineer
Alexander Kartveli who had made his home in Paris after the fall of Russia to the
Bolsheviks in 1918. The firm found some early success with their new SEV-3 Sport
Amphibian aircraft. The three-man aircraft was capable of landings on land and water
and garnered a US military contract for production as the BT-8 trainer.
The BEV-3
Motivated by the success of the BEV-3, Seversky pursued more advanced designs. His
firm moved to Farmingdale, Long Island, to a more spacious outcropping in an effort
to build their Army BT-8 trainers. A new competition netted another contract for the
Seversky P-35. The P-35 was hardly a burner at 260 miles per hour, but more
"modern" fighters with enclosed cockpits and stressed metal skins were needed by
the US Army nonetheless. Developments in Europe by this time far outclassed
American aircraft by what seemed like leaps and bounds. Regardless, the P-35
entered service in 1938 but were sorely out of date by the time of the Japanese attack
on Pearl Harbor on December 7th, 1941.
The P-43 Lancer
A new Seversky demonstrator was already in the works, this fitted with a General
Electric supercharger coupled to a Pratt & Whitney R-1830 radial piston engine and
designated by the company as the AP-4 - essentially an improved form of the P-35.
The Army liked what it saw and granted a contract for 13 evaluation models to be
designated as the YP-43 "Lancer". By the end of 1939, Seversky himself went off to
England to try and sell his products with the hope of netting more lucrative wartime
contracts from desperate European nations looking to match up to the might of the
German war machine. It was during this time that the Seversky company Board of
Directors delivered a no-confidence vote for Alexander Seversky and ousted as
company president. The firm was reformed under the Republic Aviation name and
retained the services of Alexander Kartveli as chief engineer for the firm. Seversky
himself was out of the picture.
Work on the Lancer continued. The YP-43 was fitted with 2 x .30 caliber machine guns
and 2 x 50 caliber heavy machine guns but did not feature self-sealing fuel tanks nor
protective armoring for the pilot. The P-43 Lancer entered limited production but did
not prove an answer for the US Army. An improved form of the aircraft emerged as
the P-44 "Rocket", to which the US Army became quite enthusiastic about, but
unfolding events in Europe quickly deflated such enthusiasm. As the Army looked to
the air war ongoing over France and Britain, it realized that even the "Rocket" could
not accomplish in combat what the nimble fighters over in Europe were doing. These
aircraft sported sleek designed frames with relatively powerful in-line, liquid-cooled
engines and equally powerful armament to boot. The Army made out a wish list for
their next fighter and found that it required an interceptor capable of at least 400
miles per hour at 25,000 feet with an armament of at least 6 x .50 caliber machine
guns, long range and protection for the pilot and fuel tanks for extended ranges.
The AP-10/XP-47
With war inching ever closer, time was of the essence. A new Republic design
centered around the Allison V-1710 liquid-cooled V-12 in-line piston engine - closely
resembling the powerplant found on the streamlined Bell P-39 Airacobras, Curtiss
P-40 Warhawks and the Lockheed P-38 Lightnings. The design took the company
designation of AP-10 and, by 1939, Kartveli had completed drawings for the aircraft
consisting of the smallest possible airframe. He added some impressive performance
estimates that saw the new aircraft hit speeds of 415 miles per hour (in theory). The
experimental section of the US Army, based out of Wright Field, took a closer look and
offered some subtle changes that included a slightly larger overall airframe with
added weight and more surface area. Two hardpoints were set under each wing and
armament was a strange pairing of 1 x .30 caliber machine gun and 1 x .50 caliber
machine in the upper cowling.
Sensing good things from the preliminary design and, more importantly, still in dire
need of modern fighters, the US Army rushed to get the AP-10 into production under
the prototype designation of XP-47. The program would begin development in two
complete airframes - the XP-47 and the XP-47A. The XP-47 was a full-fledged offering
complete with combat armament while the XP-47A would be a flight test model sans
combat options but intended to test out the design's validity in controlled
experiments. The program was given a window of nine months to produce the end
products.
Further review of the XP-47 design by the US Army funding department (those in
control of the money) forced yet more revisions. The wing surface area - deemed too
small on the original design - was enlarged and an additional .30 caliber and .50
caliber machine gun were added. Self-sealing fuel tanks and armoring were also now
included. These options of course drove up the overall weight of the aircraft that was
intended to be an interceptor - if an interceptor could not climb within reason, it was
no longer considered an interceptor.
Back to the Drawing Board - the XP-47B: the True Thunderbolt Prototype
By this time, the war in Europe was changing on a monthly basis as were the tactics
and technology. Pratt & Whitney unveiled their R-2800 Double Wasp, two-row,
18-cylinder air-cooled radial piston engine and rated their massive product at 2,000
horsepower. Though more fuel-thirsty than the original Allison in-line to be used, the
Double Wasp promised much more in the way of output and performance over her
predecessor. Kartveli tried a second design attempt to fit this new engine into an
applicable airframe as the diminutive AP-10 was much too small to handle such a
powerplant. The stout new design emerged with 6 x .50 caliber machine guns fitted to
the wings, adequate armor protection, self-sealing fuel tanks, large surface areas and
an operational weight of 12,000lbs. This new design was given the designation of
XP-47B while the XP-47 and XP-47A quickly fell into oblivion, the two ultimately
cancelled in full. The US Army was smitten with the prospect of this large 400
mile-per-hour beast and quickly placed a 773-strong production order for the XP-47B
on September 6th, 1942 - this before a single prototype was even made available.
Amazingly, only one XP-47B would be built while no service test models (YP-47Bs)
were ordered - quite the departure for the careful, though now desperate, US Army.
What a Turbosupercharger (or Turbocharger) Actually Does
High altitude performance was a necessity in the new design as dogfights cared little
of operational ceilings. As such, a large and complicated turbosupercharger (also
known as a turbocharger) was deemed a must for such activities. The
turbosupercharger essentially provided for sea level-rated operations at altitudes up
to the engine's critical altitude - that is - the maximum altitude an engine could
sustain its rated horsepower output at without seeing a decrease in performance. The
turbosupercharger featured a turbine that was driven by exhaust gasses from the
engine as well as a compressor with a high-speed impeller that pressurized the
incoming air. The resulting action produced high-pressure, high-density air which was
then re-delivered to the engine to maintain an applicable output at higher altitudes.
Republic engineers placed this system behind the cockpit in an effort to maintain a
proper center of gravity and improve stability. The turbosupercharger would then
require ductwork to run to and from the engine/turbosupercharger to deliver the
gasses for the required boost in performance. Once implemented, this duct system
forced the XP-47B to take on a "deep" look fuselage and gave the P-47 its universally
identifiable profile but, at the same time, added much-needed room for internal fuel
stores to power the thirsty Pratt & Whitney.
The fuselage was affixed to two elliptical wing assemblies complete with rounded
edges. The wings would contain the primary standard armament, applicable
ammunition stores and main landing gears. The tail surfaces were encased in fabric
covering for the time being while the rest of the body was of all-metal stressed skin.
The Pratt & Whitney powerplant needed a quality propeller system to make the most
out of the horsepower output and, as such, a 12 foot, 2 inch diameter four-blade
propeller system was selected to cap the nose of the XP-47B. A new problem quickly
arose, however, in implementing such a large diameter propeller blade. The tall
propeller system needed clearance along the ground during take-off and landing.
Rather than produce an ungainly looking bird with obscenely long landing gear legs, a
telescoping landing gear leg system was devised where the assembly could extend
out to 9 inches when lowered and retract that length when the leg was pulled up. This
issue was not unlike the issue forced onto the designers of the Vought F4U Corsair
fitting their own large three-blade propeller. In that particular case, the engineers
elected to use an inverted "gull" wing to offset the need for height. Ingenuity for the
Americans seemed to come naturally at this time. Unlike production P-47s, the XP-47B
featured a canopy that was hinged over to the side with an automobile-style
entry/exit door. This would later be replaced after the system was prone to jamming
and proved too cumbersome during emergency exits via parachute.
Flight Testing of the XP-47B
The XP-47B was finally constructed to the new specifications by Republic to which the
name of "Thunderbolt" was officially assigned (the US had not been in the habit of
naming its military creations until the British did so with American Lend-Lease tanks
and aircraft). The XP-47B achieved first flight over Farmingdale, Long Island, on May
6th, 1941 and - at the time - became the largest piston-powered single-engine fighter
aircraft to fly (not to mention the most expensive). The XP-47B was flown to a US
Army base at Mitchel Field for a perfect landing. By all accounts, the large aircraft was
a winner despite some oil falling burning off of the turbosupercharger and
consequently filling the cockpit with black smoke. After the first flight, some further
recommendations bought about more fine tuning including the use of a pressurized
ignition harness, wing stiffeners to combat flutter and a new type of engine oil
lubricant.
One of the biggest items of note to come out of further testing of the XP-47B was the
diving prowess of the airframe. One such power dive netted a speed of 550 miles per
hour, pulling off the fabric covering over the tail surfaces in the process. Other items
of note included the need for vast amounts of runway required to help the "Heavy"
take off as well as a "control freeze" situation encountered by the control surfaces
during steep dives - both could prove fatal to the untrained Thunderbolt pilot if not
respected.
The P-47B is Delivered
Four early-production Thunderbolts (their hinged cockpits replaced in favor of a
rearward sliding "greenhouse" type) soon emerged and, after similar power dive
incidents involving torn fabric on the tail surfaces (one such incident leading to the
death of a Republic test pilot), the surfaces were covered over in all-metal stressed
skin. The first operational-level P-47B was officially handed over to the US Army on
May 26th, 1942. In an effort to test out the new aircraft while at the same time
garnering valuable experience to new pilots, the US Army formed the 56th Fighter
Group squadron at Farmingdale to defend the northeast American coast from the
fears of German bombers encroaching across US airspace. The learning curve for
these lads was not a light-hearted affair for the squadron would lose up to half of their
delivered Thunderbolts to accidents (13 pilots killed while 14 airframes were lost).
One hundred seventy-one P-47B production Thunderbolts were produced at the
Republic Farmingdale plant in a short 6 months. The P-47C underwent extensive flight
trials with the US Army who then ultimately deemed it clear for operational combat. In
practice, the P-47 proved to have a tremendous roll rate, better than that of any
current US fighter, and offered many exceptional qualities considering her size. No
doubt the "greenhouse" canopy, raised fuselage spine and massive engine mounting
curtailed pilot vision but, in all, she was a fantastic creation from the people at
Republic. Her range was shorter than anticipated no thanks to the Pratt & Whitney
powerplant and her rate-of-climb clearly put her out of the interceptor category
altogether but she was something that no current US fighter could match.
Production was already underway at the Republic plant at Farmingdale but demand
was such that a new plant was opened up at Evansville, Indiana and Curtiss-Wright
was also enlisted to license-produce the type at their Buffalo, New York facility. With
production ramping up and the US Army ready for action, the P-47C Thunderbolt was
crated up and shipped by boat to England for final assembly and squadron training.
The first shipment arrived on the British Isle on December 20th, 1942.
P-47 Walk-Around
The Thunderbolt's stout appearance makes her one of the most memorable American
warplanes of World War 2. Her size was necessitated by the addition of the
turbosupercharger and all her applicable ductwork, causing the deep fuselage to take
shape. The turbocharger helped to balance the design and featured large diameter
ductwork running from charger to engine and back. The large air-cooled Pratt &
Whitney Double Wasp engine was contained in the extreme forward of the fuselage,
which itself was more elliptical in shape - almost an upside down egg when viewed
from the front - than one might realize at first glance. A four-bladed Hamilton-
Standard propeller (later refitted with a Curtiss Electric unit) was fitted to a simple
spinner at the opening of the engine and intake duct openings were readily present
just under the engine face. Wings were of the monoplane type and low-mounted,
somewhat forward, along the slender streamlined fuselage. The cockpit was placed
just above and slightly ahead of the wing trailing edges. The main wings themselves -
another distinguishable characteristic of the P-47 and purely a Republic trademark -
were elliptical in shape, sporting rounded edges with a straight leading edge and
tapered trailing edge while showcasing some dihedral in the forward profile. The
cockpit was situated at about the midway point of the fuselage and early
Thunderbolts maintained the "razorback" spine that contoured into the top portion of
the empennage. The empennage was dominated by a small-area vertical stabilizer
and a pair of horizontal stabilizers. The fuselage progressively tapered down to a
rounded cap at the base of the tail.
The keen observer will note the P-47s outward resemblance to Seversky's/Republic's
earlier design attempts in the Seversky P-35 and Republic P-43 Lancer respectively.
The Cockpit
Both Axis and Allied pilots having the pleasure of flying the P-47 noted the type's
exceptionally roomy interior. The cockpit (P-47D) sported clean lines and clustered
major dial groups that were well-placed. The pilot sat in what was sometimes termed
a "lounge chair" by some and air conditioning was standard. The forward instrument
panel was dominated by the top-mounted K-14A gunsight. All major in-flight readings
(navigation, altitude) were situated along the upper half of the panel while engine and
fuel controls took over the lower half. Bomb/tank selectors were clustered on a panel
along the lower left side of the forward instrument group with the throttle to the
pilot's left-hand side. The throttle contained a rotating handle to adjust the scale of
the gunsight in an effort to keep important controls within reach at all times. Overall
control of the aircraft was accomplished through a conventional flight stick with
integrated trigger. Rudders were set under the forward instrument panel at the pilot's
feet and could be folded down for long flights allowing the pilot to stretch his legs
some.
Vision from the cockpit was remembered as adequate to good. Considering the pilot's
seat was situated well behind the large engine, this was expected. The large-area
main wings also obscured downward vision and the "razorback" raised spines in
early-form Thunderbolts didn't help vision to the "six". The implementation of a
British-based "teardrop" bubble canopy alleviated the latter problem and much of the
heavy framing of the early "greenhouse" canopies was lost in the process. Test pilots
of the new canopy were elated at the refreshed vision out of the cockpit. The new
canopy slid rearwards (as opposed to the early side-opening ones) to allow for pilot
entry/exit and was first utilized on a modified P-47D-5 (as the XP-47K) in the summer
of 1943.
The undercarriage was typical of the time and categorized the P-47 as a "tail
dragger". The arrangement consisted of two single-wheeled telescoping main landing
gear legs (one to a wing) and a diminutive tail wheel under the base of the
empennage. The main legs recessed inward under the wings toward the fuselage
centerline while the tail wheel was equally as retractable at the base of the
empennage. When at rest, this configuration gave the Thunderbolt a noticeable
"nose-up" appearance and made for very poor vision out of the cockpit when taxiing
into position. The large diameter four-blade propeller necessitated the use of long
legs to help the aircraft clear a runway without the blades hitting the surface of the
pavement.
Armament
The Thunderbolt's wings were constructed with two major spars running nearly the
length of the each wing. Spars were charged with the handling of flight loads when
airborne and the carrying the wing's weight when on the ground . Republic
engineered each Thunderbolt wing assembly to fit 4 x M2 Browning air-cooled .50
caliber heavy machine guns in a staggered arrangement. The P-47 was the only
American fighter aircraft to wield this many machine guns (20mm cannon armament
was considered early on but dropped from contention). The staggered formation of
these machine guns allowed for effective feeding of the systems from four separate
ammunition holds. The power of these combined eight machine guns could effectively
engage fighters and bombers while being of equal value when tackling ground-based
targets. A single burst was enough to down most any aircraft. Such armament could
output a staggering 13lbs of blazing hot ammunition on a target per second.
In addition to its formidable machine gun battery, the P-47 made a living under the
clouds for German troops a pure hell. With underwing mounts, she could field up to
2,500lbs of conventional drop bombs or 10 x 5-inch unguided HVAR rockets useful
against ground- and water-based targets. Drop tanks could be carried in place of
munitions and situated along the fuselage centerline (x1) or underwing (x2).
One known conversion of a P-47 attempted to mount 2 x underwing Oldsmobile
20mm cannons. While an awesome prospect in theory, the fitting proved a
disappointment in practice, adding unnecessary drag and thusly lowering the
Thunderbolt's top speed by 50 miles per hour. This single P-47 was eventually
converted back to her base operating form with standard armament.
The Variants (In Alphabetical Order)
The XP-47B was fitted with a Pratt & Whitney R-2800-17 radial piston engine of 2,000
horsepower attached to a 12 feet, 2 inch diameter Curtiss Electric four-blade
propeller. The aircraft sported an empty weight of 9,189lbs and a gross weight of
12,700lbs. Maximum speed was listed at 412 miles per hour at 25,800 feet with a
maximum range of 1,150 miles at 10,000 feet. Five hundred rounds of .50 caliber
ammunition were afforded her 8 x guns.
The B-Model
The P-47B mounted the Pratt & Whitney R-2800-21 series radial piston engine of
2,000 horsepower and entered production in 1942 with deliveries to the USAAF in
England beginning in early 1943. At least 171 P-47B production models were
delivered. Many B-models were eventually relegated as trainers to get the young
pilots use to these large and heavy mounts - truly no American aircraft before it could
match the qualities (and drawbacks in some cases) of this heavy hitter from
Farmingdale. The P-47B maintained a maximum speed of 429 miles per hour with a
range of 550 miles. The service ceiling was listed at 42,000 feet with a rate-of-climb
equaling 2,560 feet per minute. A "one-off" reconnaissance form was built with the
designation of RP-47B.
The C-Model
While essentially similar to the B-models before them, the P-47C brought about a
more powerful engine series in an lengthened fuselage as well as implementation of a
droppable belly fuel tank (or bomb if need be). The external fuel tank finally allowed
for sorties to Berlin and back. The fuselage was extended by a full 8 inches which
allowed engineers to move the engine forward some and improve the Thunderbolt's
center of gravity. The addition of the centerline hardpoint added ground attack
capabilities to the Thunderbolt's toolbox. The tail section was further strengthened to
counteract the resulting stress of those power dives and a 30 gallon water tank was
added to "fuel" the water injection system of R-2800-59 engined Thunderbolts. The
first 112 P-47C models were fitted with the Pratt & Whitney R-2800-21 radial engine
of 2,000 horsepower as the R-2800-59 series engines (and their respective water-
injection systems) were not yet available. As such, only later versions carried the
improved radials with the increase of almost 300 horsepower. At least 602 C-models
were produced.
P-47C models sported an empty weight of 9,900lbs with a maximum weight of
14,925lbs. Maximum speed was 420 miles per hour at 30,000 feet with a service
ceiling of 42,000 feet and a range of 835 miles at 10,000 feet. 300 to 425 rounds
were afforded to her 8 x .50 caliber machine guns.
The All-Important D-Model...
The P-47D entered production from early 1943 onwards and proved the definitive
Thunderbolt in the family line, arriving in Britain in April. A more powerful engine with
water injection (known as "War Emergency Power" or "WEP", used for short
enhancements of performance) greeted the design. The turbocharger was revised
through better ductwork providing for improved efficiency. The pilot's position was
granted more protective armoring and engine controls were simplified while landing
gear tires were fabricated as "multi-ply" to take on the roughest of airfields. Three
drop tanks could now be fitted and underwing hardpoints (the P-47D-15 and on) could
now sport a 1,000lb bomb (one to a wing) or 10 x 5-inch rockets (5 to a wing). While
an impressive armament load, this often meant that ammunition counts for the
machine guns had to be reduced to compensate for the added weight. In some cases,
a pair of machine guns were eliminated altogether. Later production D-models fitted
the all-important bubble canopy which did away with the raise fuselage spine,
improving pilot vision to his "six" ten-fold. It was not uncommon for D-models to be
shipped unpainted from Republic factories, these appearing in their all silver bare
metal finish, and saw a slight increase to performance. A mind-boggling 12,602
D-models made their way out of the factory doors and production constituted four
large batches.
The P-47D was powered by the Pratt & Whitney R-2800-59 Double Wasp 18-cylinder
air-cooled radial piston engine of 2,535 horsepower (or R-2800-21W of 2,300
horsepower with water-injection). She operated with an empty weight of 9,950lbs and
a maximum take-off weight of 17,500lbs. Performance included a top speed of 433
miles per hour, a service ceiling of 41,000 feet, a rate-of-climb equal to 3,200
feet-per-minute and a range of 1,900 miles with three drop tanks in tow. The
maximum external ordnance weight limit was approximately 2,500lbs. Standard
armament included the 8 x wing-mounted M2 Browning air-cooled heavy machine
guns.
...With a Few Test Developments In-between
The XP-47E was generated for the final P-47B. This developmental model came
complete with a hinged canopy, Hamilton Standard propeller and pressurized cockpit
used to trial the Pratt & Whitney R-2800-59 radial engine.
The XP-47F model was plucked from a P-47B and modified as a test-bed for
laminar-flow wings. Testing revealed that the new wings would not improve
performance much and the aircraft soldiered on in other related flight tests thereafter.
She was officially lost in a fatal accident on October 14th, 1943.
Rough-Hewn P-47's From Curtiss-Wright
The P-47G was the designation assigned to Curtiss-Wright built Thunderbolts and
were essentially C-models reincarnated under the Curtiss-Wright production banner.
Quality control was somewhat lacking at the Curtiss-Wright plant in Buffalo, New York,
and production as a whole was rather slow - this being much different than the
standards at the Republic facility or the Indiana plant. As such, production of
G-models was limited to a low total of 354 examples before the plant was closed.
Many of these Thunderbolts remained stateside for pilot training, never to see combat
action.
Another Few Developmental P-47s
The XP-47H was an interesting P-47 development in that it attempted to mate the
P-47 airframe with the Chrysler XI-2220-1 16-cylinder, inverted-vee, liquid-cooled
engine of 2,300 to 2,500 horsepower (sources vary). Two P-51D-15 models were used
in this conversion test sans their armament. The complicated and untested engine
proved highly unfeasible and overly complicated to fit into the existing airframe
without major modifications. As such, the project was dropped. First flight was
achieved in July of 1945, achieving a paltry 414 miles per hour for the USAAF - far
lower than the projected 490 miles per hour originally envisioned (and reportedly
reached) by Republic. Range was approximated to 700 miles.
The XP-47J was a Republic attempt to reduce the overall weight of the airframe while
increasing the overall output of the engine. The original idea was to fit an R-2800-61
with a contra-rotating propeller system mated to a General Electric
turbosupercharger. When an effective propeller solution was not found, a basic paddle
type from Curtiss was fitted instead as was a Pratt & Whitney R-2800-57 of 2,800
horsepower. Armament was reduced to 6 x .50 caliber machine guns and internal fuel
capacity was lowered. The engine gave up the ghost after just 10 hours of total flight
time and needed replacing. The XP-47J went on to clock an impressive 500 miles per
hour in March of 1944. After Army testing revealed less than the 500 mile per hour
figure, coupled with the fact that the XP-47J would require essentially an all-new tool
production line, the project was dropped in favor of the XP-72 "Wasp Major" Super
Thunderbolt development. The XP-72 proved an impressive beast herself but the
changing war environment negated the need for such an implement and she was
never produced.
The XP-47K was an experimental P-47D production model fitted with a Hawker
Typhoon bubble canopy and cut-down rear fuselage spine to help improve pilot vision
to his all-important rear quarter. The fuselage fuel tank was increased to a degree and
several exterior modifications ensued. Test flights of the new aircraft were positive
and the variant was put into production alongside D-models. The XP-47K was later
modified to test out the wings that would eventually appear on the definitive P-47N
long-range models.
The P-47 Hotrod
The P-47M was in many ways a "special edition" Thunderbolt sprinter/hotrod designed
as superfast interceptor. This mount would be charged with chasing down Germany's
fast V-1 flying bombs randomly terrorizing Londoners. Essentially P-47D-30 models
incarnate, M-models appeared in December of 1944 and boasted a top speed of 473
miles per hour from her somewhat troublesome R-2800-57(C) radial of 2,800
horsepower ranged out to 530 miles. The turbosupercharger was once again refined
for the better and a Curtiss Electric propelled was utilized. Special airbrakes were
installed on the aircraft so she could decelerate quickly once in range of her target.
Though faster than the fastest P-51 Mustang available, this P-47 still suffered from a
thirsty radial and limited range. As well as any V-1 rockets she might have bagged,
the M-model also boasted kills against the Messerschmitt Me 262 Schwalbe
jet-powered fighter and Arado Ar 234 "Blitz" jet-powered bomber (albeit these were in
the most perfect of circumstances and conditions favoring the passing Thunderbolt,
hardly a straight-up dogfight with either). Some 130 M-models were produced though
quality control at wartime's frenetic pace developed many mechanical problems for
this Thunderbolt batch. M-models were not made available until April of 1945 -
essentially the closing months of the war.
Definitive P-47: the N Model
The P-47N became the ultimate incarnation of the Thunderbolt exhibiting exceptional
range and is oft-regarded by many former 'Bolt pilots as the finest of the breed.
Reinforced longer spanning wings with additional internal fuel tanks were part of this
near-complete redesign of an already impressive mount. Power was generated by an
improved form of the M-model's R-2800-57(C) radial of 2,800 horsepower (An
R-2800-73 and R-2800-77 were also part of the production mix). Underwing positions
held hardpoints for 5-inch HVAR rockets (5 x rockets to a wing). The wings were
lengthened a full 18 inches and the wingtips were clipped for improved rolling actions
in-flight while her landing gears were completely redesigned. The clipped wings
became the definitive identifier in this Thunderbolt variant. Controls for both throttle
and turbosupercharger were both refined. Production began in December of 1944 and
her long range made her an ideal candidate for actions in the Pacific where
land-based airstrips could prove few and far between. The revisions and refinements
took their toll on the new Thunderbolt for she sported an empty weight of 11,000lbs
and a loaded weight of 20,700lbs! This gave her an increased take-off run. Some
1,816 N-models were delivered and only served in the Pacific Theater of War.
Performance for the N-model included a top speed of 467 miles per hour, a ceiling of
43,000 feet, a rate of climb of 3,000 feet per minute and a range of 800 miles.
Same Face, New Name
F-47 became the new P-47 designation in 1948 after the US Air Force was born out of
the US Army Air Force as a separate entity (likewise the North American P-51 became
the F-51). The F-47 designation lived for a short time in American lore but found
homes in the inventories of foreign nations. As such, the F-47 is often a rare
designation used when discussing the P-47, at least in American circles.
Some in -field conversions modified a single-seater Thunderbolt into a two-seater
fitting a second seating area for a passenger under a long, rearward-sliding canopy.
While some used such creations to cavort to other nearby locales for war "goods"
such as cigarettes and women, others were used in more constructive ways such as
fielding war correspondents over designated areas.
Production Totals by Plant
In all, the Farmingdale, New York plant spit out 9,087 Thunderbolts while the
Evansville, Indiana plant produced 6,242 examples. The disappointing Curtiss plant at
Buffalo, New York, managed a low 354 production examples.
P-47 In Action Over Europe
The first P-47Cs (colored over in an olive drab and neutral gray paint scheme) arrived
in England on December 20th, 1942 and were assembled for the 4th Fighter Group.
The 4th Fighter Group at Debden was made up of Americans fighting for the RAF as
part of the "Eagle Squadrons" before America had officially committed to World War 2.
Once can only imagine the mighty transition for these young lads accustomed to
flying the lightweight and sleek Supermarine Spitfires - now faced with the imposing
"barrel-with-wings" Thunderbolt.
Thunderbolts were immediately signed up for "Ramrod" missions over Europe, that is,
escorting 8th Air Force Boeing B-17 Flying Fortress and Consolidated B-24 Liberator
heavy bombers that were taking a pounding from Luftwaffe fighters in daring daylight
raids. Germany, itself, remained out of the reach for these early Thunderbolts in the
theater and it was not yet a reality to have fighters with the range to escort a bomber
group all the way to and from their targets. To bomber crews, fighter escorts became
known as "Little Friends" for their obvious protective reasons. Luftwaffe pilots simply
needed to wait until the fighter escort turned around, low on fuel, to strike at the
hapless bomber formations. To "keep up" with the slow-moving bomber groups, P-47
pilots had to perform repeated zig-zag patterns above the bomber groups so as not to
stall or get ahead of their flock.
The first P-47 mission took place on March 10th, 1943 and was nothing more than a
fighter sweep over enemy territory. Unfortunately for the pilots, serious teething
issues quickly arose and forced the Thunderbolts back for repairs. In fact, the issues
were severe enough to ground the fleet for a whole month before taking to the skies
again. The 56th Fighter Group and the 78th Fighter Group soon came online at their
respective bases throughout England - the 78th having yet to even pilot one P-47.
Issue after issue continued to mount up for the Thunderbolts and ground crews
working feverishly and around-the-clock to correct them.
The Thunderbolts were airborne once more on April 8th, 1943, where a 24-strong
(P-47s drawn from the three squadrons) flew an uneventful mission. On April 15th,
1943, the Thunderbolt pilots soon found their first aerial engagement of the war
resulting in the downing of two enemy Focke-Wulf Fw 190 fighters from the guns of
P-47Cs of the 4th Fighter Group.
Resilient Heavyweight
The P-47s no doubt proved a tough bird to bring down, much to the surprise of the
German pilots - some who had emptied dozens of cannon and machine gun rounds
into the Thunderbolt airframe only to see it continue on its merry way. Many-a-
Thunderbolt pilot returned to England, battered and bruised, but alive to fight another
day thanks to these steady mounts. Radial engines inherently maintained a better
combat damage resiliency that did the delicate liquid-cooled inline engines.
Additionally, the large airframe of the Thunderbolt made it a relative sponge for all
types of damage, be it flying shrapnel, flak, power lines or trees at low altitudes. The
armor plating around the cockpit perhaps served Jug pilots the most - priceless
protection when and where he needed it most.
Diving to Live, Diving to Die
It was no secret the inherent power in a diving Thunderbolt. However, this action
could prove two-fold. While acceleration from a rapid drop in altitude was a key tactic
used by P-47 pilots, it could also spell their undoing. It was not uncommon for the
control surfaces of the 'Bolt to "lock up" in a power dive and potentially prove fatal to
the pilot if he could not regain control of the aircraft. One combat incident stated a
P-47 beginning a power dive from approximately 28,000 feet with recovery finally
occurring at just 5,000 feet! Keep in mind that such dives could also produce forces
too great for the average human body and, as a result, a P-47 pilot could black out
with nary a chance at regaining control of his aircraft.
"They Drew First Blood..."
On May 4th, the Thunderbolts were called on their first escort mission with Boeing
B-17 Flying Fortress bombers. Oft-harassed on nearly every sortie, the B-17s were
glad to have these stout escorts watching from their perch overhead. Engine teething
issues persisted for some of these P-47s but the Luftwaffe was in for a rude
awakening as the charging Jugs steamed out of the sky to protect the bomber fleet.
The air war over Europe was finally on even terms.
The P-47D models began arriving with their all-important updates. As more and more
deliveries of the fine fighter were filled and shipments in England received, the US
Army moved to create the 352nd, 353rd, 355th, 356th, 358th, 359th and 361st
Fighter Groups.
The P-47 vs Fw 190 - Close Finish
Versus the German Fw 190, Thunderbolt pilots soon discovered some tactics that
could best these fine German counterparts. The Fw 190 would almost always win in a
turning fight and could gain an early advantage in a dive. Acceleration generally
favored the Fw 190 as well while its potent collection of machine guns and hub-firing
cannon proved quite lethal. However, P-47 pilots held the advantage in a dive in the
long term, able to build up enough speed to outrace or catch up to any Fw 190.
Additionally, a single burst from the 8 x .50 caliber machine guns would down a
lightly-built Fw 190 with little effort while the P-47 airframe proved masterful at
absorbing such damage (even to a ridiculous degree). In the end, an expertly trained
P-47 pilot - one knowing the in's and out's of his mount - could eventually best a
German Fw 190 through strategy, patience and instinct. This became painfully clear
to the Germans as more and more P-47 pilots earned their stay across the many kill
boards plastered along the walls of squadron HQs. Becoming an ace in a P-47 was not
as uncommon as one might think.
Dive and Zoom Tactics
Despite the advantages, straight-up dogfights for the P-47 were not recommended.
Instead, "dive and zoom" tactics sprouted up as the "weapon" of choice. This
proposed that the P-47 operate higher than 15,000 feet, an altitude where the
turbosupercharger came into play for the 'Bolt and where lesser German fighters
tended to see a slight dip in performance. From this altitude, P-47 pilots could then
dive onto their targets with relative ease, fire off short-controlled bursts and then
retain momentum into an ensuing climb only to repeat the action once again. This
helped to keep the heavy P-47 from taking harm directly while making calculated
strikes against the enemy.
The Results Are In
Early results put the P-47 favorably ahead of the fabled P-51 Mustangs and Lockheed
P-38 Lightnings in the European Theater. The P-47 was called to more sorties than the
other two combined and could claim over 200 enemy fighters destroyed in a shorter
stretch of time. Comparatively, however, Thunderbolt pilots led the way in losses to
enemy aircraft but still maintained a healthy 8:1 victory-to-loss ratio and lost less
pilots overall through 1,000 recorded sorties.
Fat is Beautiful
Despite her inherent air-to-ground prowess, the USAAF felt safe in keeping their P-47s
in the bomber escort role for the time being. She was, however, eventually unleashed
on her first ground attack sortie on November 25th, 1943. The mission entailed the
bombing of a Luftwaffe airfield at St Omer. The Thunderbolts enacted their anger onto
the airfield, dropping their explosive payloads to good effect, and remained airborne
to strafe targets of opportunity while incurring the wrath of deadly-accurate German
flak teams. The mission proved a success and the P-47s returned home. The arrival of
the North American P-51B Mustangs all but nixed the P-47 from the bomber escort
role so she and her pilots would have to get use to these sort of ground attack
missions.
The 9th Air Force was officially created to take on the growing number of P-47 groups
popping up. The 9th Air Force eventually became a prime operator of the P-47 and
initially used them to escort their lighter Douglas A-20 Havocs and Martin B-26
Marauders. The first operational squadron under the 9th banner became the 358th
Fighter Group, transferring over from the 8th Air Force. By the end of it all, the
Thunderbolt found a combat niche that few fighters could boast. Numbers of the type
swelled and, as pilots grew comfortable in these large warplanes, the kill tallies also
increased. German fighters spiraled down in flames, locomotives exploded in
tremendous fireballs and enemy tank formations fell into disarray. Germany was
falling back in retreat and it had no thanks to wield in the direction of the P-47.
Ode to the Tuskegee Airmen, the Help Much Appreciated
While it is always easy and applicable to associate the Tuskegee prowess with the
P-51 Mustang, these lads began their combat legacies in P-47 Thunderbolts. The
332nd Fighter Group completed their first mission - defending B-24 Liberators from
German Messerschmitt Bf 109s - and claimed and impressive 5 enemy air kills on June
9th, 1944. On June 25th, 1944, this same group spotted and engaged a German
destroyer at Trieste Harbor with nothing more than their machine guns. Claiming the
sinking of the ship, top Allied brass was skeptical and reviewed the combat gun
camera footage only to see the ship explode beyond usefulness through direct
evidence. This destruction of a naval vessel by machine gun fire alone was a kill no
other P-47 squadron could claim. After only a month of flying their P-47s, the
Tuskegee airmen "upgraded" to used P-51B and P-51C models.
End of the Line
Most of the P-47s over Europe were inevitably replaced by the impressive P-51
Mustang when their numbers made it appropriate. Only the 56th Fighter Group was
left with Jugs and these boys were handed over the keys to shiny new P-47M "hotrod"
models.
P-47 In Action Over the Pacific
As the war in Europe fell under "control" (in favor of the Allies), sheer numbers proved
the Thunderbolt a perfect candidate for service in the Pacific Theater. The first P-47s
arrived by boat to Australia in June of 1943 and were quickly assembled and flown to
Port Moresby, New Guinea. One there, they fell into the hands of the newly arrived
348th Fighter Group as part of the 5th Air Force. Ready for combat, the short range
caused by their thirsty R-2800 radials soon came into play, forcing many a crew chief
and surrounding crewmembers to fashion homemade paper-based fuel tanks.
Operation sorties for P-47 pilots began in July of 1943 and eventually replaced the
outclassed Curtiss P-40 Warhawks and Bell P-39 Airacobras operating in the theater
(both utilizing liquid-cooled engines mind you).
Once again, the dive and zoom tactics were employed against the well-trained
Japanese airmen. Direct dogfights with Japanese fighters was discouraged and the
inherent advantages of the P-47 airframe came into play. Despite their ferocious
attitudes in flight, Japanese airmen were crippled by the simple fact that their aircraft
were not designed to take the full brunt of hot lead from American Jugs (what aircraft
realistically was?). As such, American airmen maintained a healthy advantage IF they
could maneuver their adversary into their awaiting crosshairs for the kill.
1944 saw P-47 numbers grow to incorporate three squadrons made up of the 35th,
58th and the 348th Fighter Groups. The commander of the 348th was Colonel Neel
Kearby who, on October 11th, 1943, netted no fewer than seven enemy aircraft in one
mission - though only six were confirmed as his gun camera had run out of film.
Kearby became one of America's top aces of the war but was tragically killed in action
on March 9th, 1944. Missions in the Pacific proved somewhat different than those in
Europe. Much of the terrain was ocean dotted with small island chains. What little
land there was, was often covered in thick foliage forcing bases and other facilities to
be built near the shorelines. This made for relatively easy target recognition by
passing airmen. Additionally, enemy shipping was open for the taking and
Thunderbolt pilots were not shy about unleashing bombs or machine gun fire on
hapless Japanese vessels.
The Thunderbolt proved the king of the Pacific sky when encountering large Japanese
bomber formations (even those accompanied by fighter protection). It was not
uncommon for airmen to destroy 90% of bomber formations during outings. As losses
mounted for the Japanese, such offensive-minded gestures for the Empire began to
curtail - either running out of trained pilots or simply running out of bombers to field.
It turned out that the P-47 and arriving P-51 Mustangs and P-38 Lightnings had to
eventually "fight" for targets in the Pacific sky, such was the impact of American
might in the air war - with special thanks given to the Thunderbolt.
The arrival of the P-47N in the theater soon gave near-complete advantage to the
Thunderbolt pilot, many who could (and some did) become aces on one outing - such
was the power of the new variant. The "ultimate" Thunderbolt held an inordinate
amount of power under her hood while retaining an equally inordinate amount of
firepower in her wings. HVAR rockets were part of the P-47 forte as was increased
range. Operators of the N-model included the 318th, 413th and 507th Fighter Groups
and N-models proved adept at escorting the new long-range Boeing B-29
Superfortresses coming online.
P-47s Versus the Not-So "Divine Wind"
P-47Ns played a pivotal - though not always successful role - in destroying Japanese
Kamikaze suicide fighters bent on ramming Allied warships. N-models played upon
their powerful engines to throttle at the diving enemy at full speed and engage with
bursts from their deadly .50 machine guns. On one such occasion, a P-47N pilot
rescued an American warship from a suicide attack by blasting a Japanese fighter to
oblivion through a HVAR rocket launched at the aerial target, becoming the first type
of kill credited in this fashion.
Curtain Calls
The final P-47 air kill of World War 2 occurred against a Japanese "Frank" fighter on
August 14th, 1945 - this by an airman from the 318th Fighter Group. The 507th
produced the last P-47 ace of the war. The dropping of the atomic bombs on Japan
ended the war in the Pacific. P-47s of the 414th were showcased in overhead flights
over Tokyo Bay during the "Show of Power" at the end of the war.
VJ-Day brought about the cancellation of some 5,934 Thunderbolts still on order for
they were no longer needed.
Jugs With the RAF
The Royal Air Force was a prominent operator of the Thunderbolt but limited her use
to sorties in the Far East. Some 830 total P-47s made up at least sixteen RAF
squadrons and were primarily relegated to ground strike or bomber escort sorties
replacing aged mounts. At least two P-47 squadrons soldiered on after the war in India
until ultimately replaced by the speedy Hawker Tempest. British Thunderbolts were
designated Thunderbolt Mk I (P-47D-20) and Thunderbolt Mk II (P-47D-25) with
production encompassing two batches. These American-made Thunderbolts were
shipped directly to India for final assembly. When in action, the dive and zoom
approach perfected by the Americans proved equally effective for the RAF when
combating the relentless Japanese fighters. The first P-47s made their way into
frontline British squadrons in May of 1944, replacing batches of outclassed Curtiss
Mohawks and Hawker Hurricanes. British use of the fighter encompassed South East
Asia Command through Nos 5, 34, 113, 123, 135 and 146 Squadrons made up of
Thunderbolt Mk Is. Thunderbolt Mk IIs were fielded by Nos 5, 30, 34, 42, 60, 79, 81,
113, 123, 131, 134, 135, 258, 261 and 615 Squadrons. These Jugs were ultimately
replaced by the homegrown Supermarine Spitfire as events in the Far East Theater
winded down.
The famous American Air Commando Group in the China-Burma-India Theater also
made use of the Thunderbolt, these being D-models. The 1st Air Commandos were
tied to the US 10th Air Force and provided air support to the British 14th Army in their
Burma Campaign.
International Jugs
The P-47 was maintained by the air forces of Brazil, Chile, China, Columbia,
Dominican Republic, Ecuador, Mexico, Peru, Turkey and Yugoslavia among others. The
Soviet Union received 195 examples with 8 lost during shipment.
The French Air Force fielded the Thunderbolt in anger against Algerian rebels in 1950
when their new-fangled jet aircraft proved highly unsuitable for such actions at low
altitude. While Algeria became an independent nation in 1962, the French
Thunderbolts were ridden into the ground through both combat and general wear and
tear, never to be used again.
Mexico and Brazil both flew the Jug in combat squadrons under the banner of the
USAAF in World War 2. Mexican pilots were a little discouraged in the fact that by the
time they got airborne, the Americans had virtually wiped out all Japanese resistance
in the skies.
Taiwan received a quantity of P-47Ns and put them to use against Communist China
and her MiG-15 jet fighters. Deliveries occurred in 1953 and success was limited.
Taiwan inevitably upgraded to jets supplied by their American allies.
Several nations continued to operate their Thunderbolts into the 1960's, some fielded
in active combat roles and other not. The Peruvian Air Force retired their Jugs in 1966,
twenty-four years after the type's inception into service with the USAAF.
Conclusion
By the close of World War 2, the Thunderbolt accounted for some 546,000 sorties with
over 3,752 enemy aircraft destroyed in the European Theater alone. 15,683 Jugs were
eventually produced (13,000 in a 45-month stretch alone!), easily becoming
Republic's most successful and most identifiable product. Another impressive fact for
the P-47 was that two-thirds of all production vehicles were quickly relocated to
overseas bases. 5,222 Jugs in total were lost to action while 1,722 of these were
non-combat related. The US Air Force claims that the Jug received a combat loss
percentage equal to 0.7% against the 1,350,000 hours flown. Quite a testament for
any aircraft in any era.
Post-War Jugs
P-47 fighters did not have a much of a role to play in the post-war American military.
Many were sent into storage while a few were handed down to National Guard units.
Some did serve with the newly-minted US Air Force under the SAC (Strategic Air
Command), TAC (Tactical Air Command) and ADC (Aerospace Defense Command).
In1948, the P-47 was redesignated to the "F-47" like other pursuit fighters of her time.
Jet-powered fighters eventually began to replace F-47's in the USAF inventory by
1949 while National Guard units continued their use of the Thunderbolt into the
mid-1950's.
The Jugs Are Rejected from Action in Korea
While her air-to-ground capabilities would have been a godsend in a conflict like the
Korean War, the request for F-47s by Lieutenant General Geroge Stratemeyer was
denied due to the logistical details that would have to be made in prepping and
fielding the F-47 for operations over Korea. Despite their wartime numbers, F-47
spare parts proved hard to come by in the early 1950s. The F-47, therefore, was not
to see action in the Korean War.
Regardless, her legacy was firmly entrenched in history's greatest air war and the
P-47 proved a mount so capable to any task that she was assigned - whether it was to
make an ace out of her pilot or strike at important ground targets - that the "Jug"
became an all-star through and through with her capabilities forever held in high
regard.
Miscellaneous Offerings
Amazingly, the Republic P-47 Thunderbolt weighed more than a fully-loaded Dornier
Do 17 bomber. An important fact to consider when the P-47 was designed from the
outset as an interceptor. Her pilots often referred to her amazing agility with great
remembrance in spite of her size which makes the weight factor that much more
unbelievable. The final operational weight of later production P-47s could easily be
measured in TONS let alone pounds.
The Thunderbolt Reincarnated
The Fairchild Republic A-10 "Thunderbolt II" receives her namesake designation from
the Republic P-47 lineage. Both generally conduct similar ground strike roles, the A-10
with a bigger gun. While the P-47 garnered the nickname of "Jug", the A-10 takes on
the affectionate nickname of "Warthog". To date, no viable replacement has been
found for the A-10 Thunderbolt II, despite her advancing age. Likewise, the P-47 was
never directly replaced - she was simply forced out by the jet age.
Source: http://www.militaryfactory.com