History of Submarine Aircraft Carriers

Japanese I-400 submarine aircraft carrier.

The US Navy is very close to possessing a sub-to-surface aerial vehicle, a “flying Sub” in the Tomahawk Block IV cruise missiles. The latest version of the highly effective Tomahawk that is fired from torpedo tubes has the ability to loiter for hours and change targets in mid-course. It is still an expendable weapon though, meaning it can’t return to the parent vessel for rearming. It can only be a matter of time, we think, until a true sub-launched UAV is built with Tomahawk technology, or perhaps the missile itself adapted for this role. 

The only nation in history to make practical use of aircraft launched from submarines were the Japanese in World War 2. The large I-400 class weighed 5223 tons on the surface and carried 3 seaplanes. All 3 were ready for combat when the war came to an end in 1945, but their impact by then likely would have been limited. Combined Fleet has more details: 

 While Japan built many submarines that were larger than those of other Navies, the three Sen Toku boats were far larger than anything ever seen before.  Some 60% larger than the largest contemporary American submarine, USS Argonaut, they had more than twice her range.  The most unusual feature was that they each carried three floatplane bombers (and parts for a fourth), a feat never achieved by any other class of submarine.  These aircraft folded to fit into the 115-foot cylindrical hangar, which was slightly offset to starboard and opened forward to access the catapult.  The huge double hull was formed of parallel cylindrical hulls so that it had a peculiar lazy-eight cross section, and may have inspired the Soviet Typhoon-class built some 40 years later.  Although aircraft must be considered their primary armament, they also carried a formidable torpedo battery and the usual 14cm deck gun.  Anti-aircraft armament included ten 25mm cannons in three triple mounts and one single.  Each of these boats had radar and a snorkel. 

Before the war Britain experimented with aircraft launched from its M class boats,  large monitor submarines with a 12 inch gun. Taking the place of the main battery was a hangar and a small seaplane, as Wikipedia describes:

Her 12-inch gun was removed, replaced by a small aircraft hangar, the work being completed in 1928. This could carry a small Parnall Peto seaplane, specially designed for the M2 and which could be launched by hydraulic catapult within a few minutes of surfacing. The aircraft would land alongside the submarine on completion of its sortie and be winched aboard using a crane. The submarine was to operate ahead of the battle fleet in a reconnaissance role, flying off her seaplane as a scout.

British Submarine M-2 retrieves her seaplane.

Also the US conducted similar tests on its S-1 from 1923-1926.

The Germans experimented with autogyros from their subs. Attached to a long cable from the parent vessel, the craft were used for surveillance duties. Not surprisingly, these Focke Achgelis Fa 330 were also known as rotor kites.

During the Cold War the Soviet Navy never seriously contemplated aircraft carrying submarines, while the USN initiated several studies. Under the title Project Flying Carpet, plans were from a 10,000 ton vessel able to carry 8 aircraft in 2 hangars. The initial aircraft dubbed AN-1 was a modified F-11 Tiger naval fighter, which already possessed the required folding wings. 

Testing was carried out on the Regulus cruise missile submarine USS Grayback, which had a large hangar. Since there was no way for the planes to land on a return trip, future testing would have involved more practical VTOL aircraft. In any event the ship was never built, with the Navy siting dubious operational requirements as well as the lack of shipbuilding capacity, as the US SSBN and nuclear attack submarines programs got under full steam. 

Plans continue for launching unmanned aerial vehicles from submarines in the War on Terror. Northrop has proposed using the sub-launched Tomahawk’s vertical tubes for UAVs from a stealthy affordable capsule system (SACS). Raytheon plans a similar test next year, launching the craft from a submerged submarine’s trash disposal unit! 

Several issues argue against using a manned flying sub for this role, including the space limitations on US submarines. Most importantly is the technical problems arising from such an undertaking that will undoubtedly (given past history) lead to decades long R&D, much like the successful but troubled attempt to create a helicopter that flies like an airplane, the V-22 Osprey, as one example. While we’ve no doubt US industry and the Military can do most anything its sets its mind to, the question soon arises if such a costly undertaking is really necessary. The added cost of a manned flying sub as Congress and the US public grow increasingly weary of Big Ticket arms which are often useless for the wars we most often fight, would also be a cause to discard such a daunting undertaking.

Special operations troops prepare to launch a UAV from the deck of submarine USS Alabama.