How An Airship Became a Flying Aircraft Carrier

Picture this: An immense flying craft whose enormous size belies its speed; despite moving at 88 feet per second, it appears to be standing still. From below, you can see a small, recessed opening in the behemoth’s underbelly. You watch as a small aircraft emerges from this opening, followed by another, and another. These “parasite” crafts circle for a few minutes before returning to the opening and retreating into their mothership. What may sound like a description of an Imperial Star Destroyer was actually a very real and very innovative project pursued by the U.S. Navy in the wake of World War I.

In this pre-radar age and faced with the possibility of a conflict with Japan, the U.S. had an urgent need for a way to monitor the immense openness of the Pacific Ocean. Airships, having proven themselves in various capacities during World War I, seemed to provide the perfect solution. Compared to traditional navy ships, they could be built relatively quickly, were cheaper to operate, and required fewer crew to do so. It was envisioned that an entire squadron of rigid airships could act as a scouting fleet from 5,000 feet in the air, visually covering thousands of square miles each day. If each of those airships were able to launch and retrieve their own scouting airplanes, that range could be increased exponentially, far more than any naval vessel was capable of. They were essentially creating a flying aircraft carrier.

The idea was groundbreaking but not without merit. Previous testing, including a successful hookup between the TC-3 Army blimp and a Sperry Messenger  in 1924 over Scott Field, Illinois, served as a proof-of-concept for the airship/parasite fighter program. In 1926, the Navy acquired authorization and funding to build two scouting airships with integrated hangars. Two years later, after holding a design competition open to the world, the Goodyear-Zeppelin Company of Akron, Ohio, was contracted to complete the vessels. Additionally, Goodyear was tasked with further developing the “trapeze” system designed by the US Navy to be used in deploying and recovering the requisite parasite aircraft.

These two airships, later known as USS Akron and USS Macon, began construction in 1929. In the same year, an operational trapeze was installed onto the USS Los Angeles (an airship acquired from the German Zeppelin company in 1924) for testing and further development. Despite some early setbacks and a slight learning curve for the test pilots, the trapeze concept proved viable. These early hook-on tests were performed with a Vought UO-1 biplane modified with a “skyhook” to latch onto the airship’s trapeze.

In March 1930, six N2Y-1 training aircraft were acquired from the Consolidated Aircraft Corporation for use until a more suitable and purpose-built aircraft could be procured. Preliminary design contracts for such an aircraft would eventually be awarded to both Curtiss and General Aircraft in May of the same year, with the first functional prototypes being delivered in 1931 and 1932, respectively. General’s XFA-1 exhibited numerous issues during initial testing, and due to internal reorganization efforts within the company, further development proved to be slow and out of pace with Curtiss’ offering. Called the XF9C-1, the Curtiss design tested well from its onset and was eventually selected for the scouting aircraft role aboard the Akron and Macon. The Navy ordered six aircraft in total.

Engineers from Curtiss and the Bureau of Aeronautics would review and make changes to the XF9C-1, including raising the upper wing height, implementing single-strut landing gear, and installing a more powerful engine, creating the XF9C-2. Provisions were also made to accommodate a 30-gallon auxiliary fuel tank to be carried under the fuselage. This tank would eliminate the landing gear completely but would exponentially increase the operational range of the aircraft. While not specifically designed as a fighter, two .30 caliber machine guns were fitted to each craft.

Designated F9C-2 Sparrowhawks, the finalized planes were delivered to the Navy in September 1932. Each aircraft received a distinctive livery and was embellished with a “Man on the Flying Trapeze” insignia. A request for volunteer pilots was fielded in late 1930 and was met with an overwhelming response. Lt. Daniel Ward Harrigan was the first to receive orders, and in 1932, made the first successful hook-on flight to the USS Akron.

Sparrowhawk Operational History & Legacy

The Sparrowhawks would see a modest but promising operational history aboard the USS Akron up until the airship’s crash in April 1933. Throughout that period, the novelty and marvel of engineering inherent in the Sparrowhawk project spurred numerous demonstrations for political leaders, military officials, and foreign dignitaries. Scouting drills performed with two and three aircraft proved successful, allowing a single airship to sweep a path nearly two hundred miles wide. After the loss of the USS Akron, the Sparrowhawks found a new home in the hangar of the USS Macon. They continued to play a vital role in airship operations and demonstrated their effectiveness during various war games and fleet exercises through 1935.

On February 12, 1935, the USS Macon was lost over the Pacific Ocean after experiencing a structural failure in fierce winds. Two members of the crew and four Sparrowhawks went down with the airship. After the loss, discussions of new airship construction were held, but the extensive cost of such a project proved unmanageable.

Despite this, the appeal of flying aircraft carriers would persevere through the coming decades. The 1940s saw development of a parasite fighter to be carried inside a B-35 or B-36 bomber. Known as the XF-85, this diminutive, egg-shaped jet fighter designed by the McDonnell Aircraft Corporation would never see full-scale production. In 1951, Convair modified an F-84E Thunderjet fighter to be recovered by an RB-36F bomber, and testing proved successful enough to be put into limited service with the Strategic Air Command.

The Remains of the Lost Sparrowhawks & the Sole Survivor 

The wreck site of the USS Macon remained unknown until 1990 when a Navy deep sea submersible located its debris fields. Video of the wreck was captured in 1991 and included images of the lost Sparrowhawk fighters, with some still adorning their skyhooks and remnants of their bright liveries. In 2006, a joint operation between multiple agencies including NOAA, Stanford University, and the Monterey Bay National Marine Sanctuary would create a high-definition photo mosaic of the wreck using nearly 14,000 pictures taken from a remote submersible. The site was added to the National Register of Historic Places in 2010.

Only one Sparrowhawk survives to this day, and you can see it on display at the National Air and Space Museum’s Steven F. Udvar-Hazy Center in Virginia. Presented in its colorful paintjob and Flying Trapeze insignia, it serves as a reminder of the heyday of airships and the potential they represented: a feat of engineering seemingly from the space-age that was achieved less than 30 years after humankind first took flight.