Airships had previously been used as long range bombers by the German Navy, targeting London and the east coast of England from bases on the continent between 1915 and 1918. Large, slow-moving, and filled with highly flammable hydrogen gas, the Zeppelins were extremely vulnerable to fighter aircraft and were forced operate at high altitudes, out of the fighters’ range. However, this made accurate bombing impossible, rendering them obsolete by the end of the war.
Airships could stay aloft for days on end and cover thousands of miles, making them ideal scouting vessels. The American navy realised that if the airships could be adapted to carry fighter aircraft, they would be able to defend themselves from enemy attack too. So they set about improving the Zeppelin’s design to suit their purposes.
Built by the Goodyear-Zeppelin Corporation, the USS Akron was ‘launched’ in 1931, followed by her sister ship, the USS Macon, in 1933. Instead of hydrogen, they were filled with helium, a rare noble gas that is inert and therefore not a fire hazard. While the hull was strengthened thanks to a deep ring design, the tail was lightened and the stabiliser fins then attached to it. This was to be a crucial design flaw.
At 239m long they were a similar length to a Yorktown Class aircraft carrier and could transport four or five Curtiss Sparrowhawk fighter biplanes. Powered by eight 560hp petrol engines and with a cruising speed of 50 knots, they had a range of 10,580 nautical miles. In May 1932 Akron successfully launched and recovered Sparrowhawks on several occasions, using an ingenious trapeze system.
Controlling the Akron proved rather more challenging. In April 1933 she encountered severe weather off the coast of New England and was battered by strong gusts of wind. In attempting to fly upwards with the ship’s nose in the air, the pilot inadvertently allowed the vulnerable tail to strike the water, tearing off the lower fin. She fell into the Atlantic, and, without life jackets or rafts, all but three of the crew drowned or died of hypothermia. Among them was Admiral William A Moffett, widely known as ‘the Air Admiral’ and a key advocate of the airship programme.
Launched in the same month the Akron was lost, the USS Macon participated in naval exercises, including a publicity stunt involving the heavy cruiser Houston which was bringing President Roosevelt back from a trip to Hawaii.
Macon’s fortunes were reversed in February 1935 when once again the flimsy tail proved its downfall. Flying off California she was caught in a storm. The upper tail fin, weakened from a previous buffeting, sheared off, puncturing the airship. She drifted gently down from a height of nearly 1,400m and settled on the sea. This time around two crew-members died, and with them, the US Navy’s airship experiment.