Here's What You Need to Know: The juiced-up engines of the P-47Ms were plagued by serious technical problems.
Pilots nicknamed early-model P-47 Thunderbolts the “Razorback,” a reference to the chunky fighter plane’s angular canopy. However, the name was more generally appropriate—like a wild boar, the hulking single-engine “Jug” was tough and hard-charging, and its eight .50 caliber machine guns packed a hell of a punch.
Lugging underwing fuel tanks, Thunderbolts based in Britain could accompany four-engine B-17 and B-24 bombers of the 8th Air Force on dangerous raids deep over Nazi Germany—and still engage German fighters on roughly even terms, especially while diving.
However, starting mid-1944, the Allied fliers grew concerned about new Nazi turbojet-powered Me-262 fighters and rocket-powered Me-163s that could outrun the speediest Allied piston-engine aircraft like the Mustang or British Tempest by 100 miles per hour or more. V-1 “Buzz Bomb” cruise missiles bombarding London, though slower, also proved difficult for Allied fighters to intercept.
On its own initiative, Thunderbolt manufacturer Republic set aside four bubble-canopy P-47Ds from its production line in Farmingdale, New York and fit them with souped-up Pratt & Whitney R-2800-57 Double Wasp engine with a turbo-supercharger. Together, these could generate 2,800 horsepower.
At high altitude, the yellow-painted YP-47M prototypes could attain a climb rate of 3,500 feet per second and a maximum speed of 473 miles per hour in level flight—though some pilots reported achieving 490 to 500 mph when using Wartime Emergency Power. This made the P-47M arguably the fastest piston-engine fighter to see combat in the war—though still slower than the Me-262’s 540-miles per hour maximum speed.
Though Republic produced more radical XP-47H and J prototypes that could go even faster, the YP-47 could be easily put into production, so in September 1944 the Army Air Corps approved a limited run of 130 P-47M-1-RE aircraft. These were delivered in December 1944 and began to be received by their sole operator, the elite 56th Fighter Group based at Boxted Airfield near Colchester, England on January 3.
The 56th, better known as Zemke’s Wolfpack after its legendary first ace commander, was the only unit in the strategic-bombing-focused 8th Air Force not to trade its Thunderbolts for P-51D Mustangs, a sleeker and more agile (though less robust) fighter. The Wolfpack’s three squadrons completed conversion to the P-47M by March, each with a unique camouflage scheme: dark black wing-tops for the 61st, green/grey disruptive pattern for the 62nd, and a striking blue/teal pattern for the 63rd.
The 56th also received new experimental T48 .50-caliber incendiary rounds designed to ignite kerosene jet fuel, which has a higher combustion temperature. The 500-grain rounds, manufactured by the Des Moines Ordnance Plant, were stuffed with 5.4 ounces of incendiary composite—twice the quantity in the standard M1 round.
However, the juiced-up engines of the P-47Ms were plagued by serious technical problems. After a Thunderbolt crash landed due to engine trouble, a crack ignition harness was discovered. Then, on February 26, a problem with the fuel carburetor diaphragm was identified, causing the P-47Ms to be grounded while a local company built new gaskets.
But these fixes didn’t bring an end to the P-47M’s woes. On an escort mission on April 4, six out of fourteen Thunderbolts had to abort mission with engine trouble. The breakdowns took a deadly turn between April 11 and 15 as three pilots were killed in engine-related accidents. The P-47Ms were grounded again on April 16, and the Wolfpack pilots reluctantly began training on Mustangs.
Meanwhile, technicians poured over the trouble R2800-57’s engines—and discovered rust in the pistons. The super Double Wasp engines had been improperly sealed for transport across the Atlantic, allowing humid ocean air to corrode the pistons.
By March 25, replacement engines had been procured and the 56th was back to operational status. Despite the growing paucity of Luftwaffe targets, the P-47M went on to distinguish itself performing exactly the kind of mission it had been designed for—shooting down Nazi jets.
In fact, the P-47M’s first two jet kills occurred prior to solving the corrosion problem. On March 14, three P-47s of the 62nd fighter squadron swooped down upon two low-flying Arado 234B jet bombers. The twin-engine jet bombers were likely targeting the battered Ludendorff Bridge in Remagen over which the U.S. 1st Army was pouring into Germany. The P-47Ms, roughly equaling the Arado’s in speed, shot down both.
Then on March 25, Wisconsinite Major George Bostwick, commander of the 63rd Squadron, and wingman Edwin Crosthwait dispatched two Me-262s as they came in for a landing at Parchim airfield—a time at which jet fighters were notoriously vulnerable. Bostwick and his Thunderbolt “Ugly Duckling” (pictured together here) ended the war with eight air-to-air kills.
Though the Luftwaffe was increasingly crippled by a lack of fuel and trained pilots, Me-262’s still posed a deadly threat to U.S. bombers. Fifty-three Thunderbolts were escorting a raid targeting Regensburg on April 5 when a lone Me-262 came streaking in from 3 o’clock at over 500 miles per hour, zipped unscathed through a hail of defensive machine gun fire and blasted a B-17 out of the sky with its four powerful 30-millimeter cannons. The escorting Razorbacks tore after the speeding jet as it peeled away at 9 o’clock—including “Devastatin’ Deb,” piloted by Captain John C. Fahringer.
Stephen Chapis described the action in Allied Jet Killers of World War II:
“The P-47s jettisoned their tanks and headed down in pursuit. 1st Lt. Phillip Kuhn fired first, before overshooting, after which Fahringer rolled in on the Me-262’s tail and let it have several bursts to no effect. However, the German pilot then made the fatal mistake of tightening his turn, which allowed Fahringer to close into lethal range. At 500 yards, he opened up again with this Thunderbolt’s eight .50-cal machine guns, and as the smoke began pouring from the jet Fahringer saw something go down the right side of his P-47. It was the pilot of the Me 262.”
On April 10, Lieutenants Walter Sharbo and Bill Wilkerson shot down two more Me-262s over Muritz lake while returning from a fighter sweep over Berlin. These were the last two aerial victories of the 56th Fighter Group.
Three days later, after failing to encounter enemy fighters on an escort mission, the Wolfpack swooped down on Eggebek airfield, their chattering machine-guns expending 85,000 rounds and destroying ninety-five parked aircraft on the ground.
The new incendiary ammunition proved especially devastating. After the German surrender, an air force report enthused “…enemy aircraft burned after having been hit only two or three times. . . . One pilot destroyed 10 aircraft on a single mission by firing short bursts.” This may be referring to 2nd Lt. Randall Murphy, whose gun camera recorded the destruction of ten aircraft during the Eggebek strike.
Zemke’s Wolfpack ended the war the top-scoring U.S. fighter group of the 8th Air Force, with 665.5 recognized aerial kills—or one thousand aircraft destroyed, including those strafed on the ground. The P-47Ms, which served after the Luftwaffe was largely defeated, claimed only fifteen of those victories—though that included at least seven jet aircraft. Twelve P-47Ms were lost in accidents, and two shot down by ground fire, but not one fell in air-to-air combat.
In recognition of the Wolfpack’s achievements, a P-47M was displayed under the Eiffel Tower for a victory celebration that July. Meanwhile, Republic developed the P-47M into to the ultimate P-47N model, 1,800 of which were built. Though slightly slower than the P-47M due to greater weight, the N was modified to fly up to 1,800 miles on internal fuel thanks to additional tanks incorporated in the wings—a useful quality for the long-range missions it flew in the final months of the War in the Pacific.
Sébastien Roblin holds a master’s degree in conflict resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing, and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.
This article first appeared in January 2019.
Image: Wikimedia Commons