Submarine aircraft carrier
A submarine aircraft carrier is a submarine equipped with aircraft for observation or attack missions. These submarines saw their most extensive use during World War II, although their operational significance remained rather small. The most famous of them were the Japanese I-400 class submarine and the French submarine Surcouf, although small numbers of similar craft were built for other nations' navies as well.
Most operational submarine aircraft carriers, with the exception of the I-400 and AM classes, used their aircraft for reconnaissance and observation. This is in contrast to the typical surface aircraft carrier, whose main function is serving as a base for offensive aircraft.
Germany was the first nation to experiment with submarine aircraft carriers, initiated by the Imperial German Naval Air Service commander Oberleutnant zur See Friedrich von Arnauld de la Perière who commanded a unit of two Friedrichshafen FF.29 reconnaissance seaplanes in Zeebrugge. One of the first U-Boats to arrive at the Zeebrugge base was Kapitänleutnant Walther Forstmann's SM U-12, which was to play the role of submarine aircraft carrier.
The unarmed FF-29 seaplanes were modified to carry 26 1⁄2-pound (12.0 kg) bombs. On 25 December 1915, one of the newly modified aircraft flew across the English Channel and up the River Thames, dropping bombs on the outskirts of London, although they caused only minor damage. Although pursued by British fighters, it returned to base safely. On this first bombing mission it was apparent that the aircraft suffered more from a lack of range.
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