North American XA-38 Grizzly

North American XA-38 Grizzly The North American XA-38 Grizzly was a prototype ground-attack aircraft and heavy escort fighter developed by North American Aviation for the United States Army Air Forces late in World War II. Conceived to supply concentrated firepower against armored vehicles, shipping, and fortified positions, the XA-38 combined powerful armament with twin-engine performance tailored to contested airspace. The program intersected with procurement priorities driven by leaders and institutions such as General Henry H. Arnold, Wendell Willkie-era industrial policy debates, and postwar force planning.

Development and design

The XA-38 originated from a United States Army Air Corps requirement to replace earlier attack types like the Douglas A-20 Havoc and augment efforts against German armored divisions, Imperial Japanese Navy shipping, and fortified coastal targets. North American Aviation, led by figures associated with the P-51 Mustang program, proposed a heavily armed twin-engined design derived from contemporary NA-73X development practices. Design objectives emphasized integration of the T35 75 mm cannon—a large-caliber weapon also evaluated for turreted ships and M4 Sherman anti-armor adaptations—and concentrated forward fire from Browning M2 machine guns or M4 autocannon mounts. The proposal was evaluated alongside programs overseen by the Aircraft Branch of the War Department and procurement officers influenced by theater commanders such as General Douglas MacArthur and General Dwight D. Eisenhower.

Technical description

The XA-38 featured twin Pratt & Whitney R-2800 double-row radial engines housed in nacelles common to late-war designs, paired with a robust airframe incorporating armor plate influenced by Bell P-39 Airacobra survivability studies and crew protection concepts from Northrop P-61 Black Widow programs. Armament centered on a single 75 mm cannon firing through the propeller hub or fuselage, mounted with recoil management systems derived from naval gun mounts tested at Naval Ordnance Test Station installations and ordnance calibrations performed at Aberdeen Proving Ground. Complementary fixed weapons included multiple .50 caliber machine guns for strafing, with ammunition stowage and ballistics distribution studied in conjunction with ballistic research at Langley Research Center and ordinance bureaus of the Department of War. Systems engineering drew on wind tunnel data from California Institute of Technology collaborators and structural loading analyses similar to those used on North American P-82 Twin Mustang proposals. Crew accommodations reflected tactical doctrine from Mediterranean Theater of Operations and Pacific War close-support missions.

Prototypes and flight testing

Two prototypes were ordered and one was completed; the first XA-38 conducted initial flight tests in 1944 under United States Army Air Forces flight test supervision. Flight trials involved instrumentation and performance measurement procedures coordinated with personnel from Wright Field, including endurance and gunnery assessments alongside contemporaneous programs such as the Lockheed P-38 Lightning modifications and Republic P-47 Thunderbolt ground-attack trials. Test results showed promising low-level handling and effectiveness of the heavy cannon against armored targets, but highlighted issues with recoil damping, weight distribution, cooling similar to challenges reported on the B-29 Superfortress program, and evolving tactical priorities driven by theater commanders including Admiral Chester Nimitz and General Joseph Stilwell.

Operational evaluation and cancellation

Operational evaluation was overtaken by strategic shifts late in World War II and by postwar restructuring of United States armed forces procurement under the War Department Reorganization Act debates. With the European conflict winding down after VE Day and resources redirected to the Pacific Theater and nascent Cold War concerns, the XA-38 lost priority to multi-role fighters and emerging jet projects managed by organizations such as Convair and Northrop Corporation. Budgetary decisions influenced by leaders like Secretary of War Henry L. Stimson and procurement reviews at Wright Field concluded that specialized heavy cannon attack types were less essential than more versatile platforms. The program was cancelled before production orders could be placed; surviving prototype evaluation records were archived alongside material from programs such as the Curtiss-Wright XP-55 and Bell XP-59.

Surviving aircraft and legacy

No XA-38 entered squadron service; the completed prototype was eventually scrapped or placed in storage, with components used as study material by engineers at institutions including National Advisory Committee for Aeronautics laboratories and industrial design teams at North American Aviation for future projects. The XA-38 influenced later ground-attack and anti-shipping concepts in the Korean War era and contributed lessons to gun-armed aircraft designs like the Douglas A-26 Invader upgrades and experimental cannon installations on fighters studied by USAF research units. Archival photos and technical drawings survive in collections at repositories such as the Smithsonian Institution and the National Museum of the United States Air Force, where researchers trace lineage from late-war prototypes to Cold War attack doctrines.

Category:Prototype aircraft Category:North American Aviation aircraft