The Douglas A2D Skyshark: America’s Ambitious Turboprop That Never Took Flight

In the immediate aftermath of World War II, military aviation was undergoing a technological revolution. Jet engines promised unprecedented speed and power, yet piston-powered aircraft were still the workhorses of carrier decks around the world. In this time of transition, the Douglas A2D Skyshark emerged—a daring attempt to propel the US Navy’s carrier strike force into the future using advanced turboprop technology. The Skyshark, intended as a high-speed, heavy-hitting successor to the legendary AD Skyraider, ultimately became an intriguing “what if” in the annals of aviation history.

A Bold Vision: The Turboprop Era

By the late 1940s, engineers and strategists recognized the need to replace piston-driven attack aircraft with something faster, tougher, and more versatile. The Skyraider had performed spectacularly in its close air support and strike roles, but its big radial engine was nearing the end of its developmental journey. Enter the turboprop: a hybrid engine, using a jet’s gas turbine to drive a propeller, promising more thrust and better high-altitude performance while retaining the reliability and short takeoff abilities critical for carrier operations.

The Navy wanted these performance gains without jumping fully to jets, which at the time required much longer decks, struggled with slow throttle response at low speeds, and were less suited for all-weather, precision strike missions.

The A2D Skyshark Takes Shape

Douglas Aircraft, already famous for the robust SBD Dauntless and newly beloved AD Skyraider, set out to design the next evolutionary step in naval attack aviation. The result was the A2D Skyshark, a single-seat attack aircraft bristling with innovation.

Powerplant: The Skyshark was centered around the Allison XT40, a turboprop engine rated at a staggering 5,500 shaft horsepower—by far the most powerful turbine-propeller combination attempted in a carrier aircraft at the time. The twin contraindicating (counter-rotating) propellers were designed to counter torque and provide efficient thrust at both low and high speeds.

Design: The Skyshark bore a strong family resemblance to the Skyraider, with a broad, straight wing, substantial landing gear for carrier operation, and armored protection for the pilot. But under the skin, it promised much higher top speeds—up to 500 mph—and a bomb load rivaling early jet fighters.

Armament: Four 20mm cannons in the wings, hard points for bombs, rockets, and torpedoes—a versatile payload for both ground attack and anti-ship roles.

Growing Pains: The Engine That Undermined Everything

Despite its impressive blueprints, the Skyshark was dogged by a host of technical problems—most of them stemming from its heart, the Allison XT40 turboprop engine.

Complexity: The XT40 was effectively two engines connected to a common gear case, driving dual propellers spinning in opposite directions. While this arrangement offered theoretical advantages, it introduced reliability nightmares. Gearbox failures, surges, and catastrophic breakdowns plagued the prototypes.

Delays: Engine teething issues repeatedly set back test flights. Development dragged out as the Navy and Allison scrambled to improve reliability and tame the turbine’s tricky response at different power settings.

Tragedy: On December 19, 1950, the first prototype crashed when the powerplant failed catastrophically, killing legendary test pilot Commander Hugh Wood. This tragedy cast a shadow over the entire program.

The Navy’s faith in the XT40 faded. As years passed and technical solutions remained elusive, the Skyshark program limped forward, never escaping the shadow of its unreliable engine.

The Shifting Winds of Innovation

By the time the A2D finally began to show its potential in limited flight tests, the world had moved on:

Carrier technology improved: Angled flight decks, stronger catapults, and jet arrestor gear allowed true jet aircraft to safely operate from carriers.

Jets matured: New naval jets offered better speed, bombloads, and easier logistics than the troublesome turboprop.

Skyraider success: The “old” AD Skyraider proved so durable and versatile that it continued to earn accolades in the Korean War and even into Vietnam, filling the very roles the Skyshark was supposed to take over.

The result? After only a dozen prototype and pre-production aircraft were built—none of which saw a day of fleet service—the A2D Skyshark was quietly cancelled in 1954.

Legacy: A Fascinating “What If”

Though it never became an operational machine, the Skyshark left a small but distinct mark on aviation history:

Engineering Lessons: Its ambitious powerplant pushed both Allison and US Navy engineers to their limits, teaching valuable lessons that would inform future turboprop and jet development.

Aesthetics and Influence: Its profile—sleek, purposeful, almost futuristic—has made it a favorite among historians and modelers, while its story stands as a cautionary tale about the risks of combining too many new technologies at once.

Rare Survivor: Only one complete A2D survives today, preserved at the Gillespie Field Annex of the San Diego Air & Space Museum, a silent monument to a technological gamble that barely left the runway.

In Retrospect

The story of the Douglas A2D Skyshark isn’t just about an airplane. It’s about an era of breathtaking ambition and breakneck technological change, when the future of air combat was still up for grabs. The Skyshark represents the hopes pinned on turboprops—a path ultimately abandoned in favor of the pure jet. And yet, its short, troubled life reminds us that innovation sometimes means knowing when to let go and move on.

In the end, the Skyraider—the “old school” piston star—became the true legend, while the Skyshark, with its promise of power and speed, became a fascinating footnote.