The USS Akron
(ZRS-4) was one of four US naval airships
. Unlike modern blimps
, which are basically giant gas bags, the Akron
had a metal frame and was held aloft by 12 separate helium filled chambers suspended within the interior of the airship
, which meant that its crew of 89 could live and work inside the craft. The ship was also much, much larger than modern-day blimps; at 785 feet, it was longer than three 747s
, and was the largest aircraft ever built up to that time. Eight 560 hp engines propelled the vessel to a top speed of 81 mph, and the ship had an operational ceiling of approximately 26,000 feet. The most spectacular feature of the Akron
was its capability to serve as a flying aircraft carrier
for its complement of four fighter planes, which were housed in the ship's massive belly and launched from trapeze-like hooks while the ship was in mid-flight.
After the US Congress authorized the construction of two naval airships in 1926, a competitive bidding process was won by Goodyear-Zeppelin Corporation, which began construction of the Akron in October 31, 1929 and completed her on August 8, 1931. The Akron's total cost of $4.5 million dollars made her the most expensive aircraft ever built up to that time.
Building upon the mistakes of the USS Shenandoah and the successes of the USS Los Angeles, the Akron incorporated many new and innovative design features. For example, the engines were mounted on 90º swivels and were reversible, allowing them to deliver thrust from any angle which greatly increased maneuverability and aided with landing. Rather than the traditional sequence of exterior rings of previous Zeppelins, the Akron had a much stronger frame of internal rings. In addition, the Akron had three keels as opposed to the single keel design which had previously been standard. One keel was placed on the top of the ship, with the other two placed on either side at 45º below horizontal, providing unprecedented strength and access to all parts of the ship. Moreover, the Akron was the first airship built from the outset to be floated with helium, which allowed for its designers to fully take into account the lift properties of that gas as compared to the slightly greater lifting power of hydrogen gas.
The Akron made her maiden flight around her construction facility in Akron, Ohio on September 23, 1931 and was then delivered to her new home base at the Naval Air Station in Lakehurst, New Jersey, where she was commissioned on Navy Day, October 27, 1931. Over the next 20 months, the Akron, was involved in numerous fleet exercises, equipment-testing experiments, and publicity cruises, logging approximately 1,700 hours of airtime on separate 74 flights, 73 of which passed without incident.
But on the evening of April 3, 1933, the Akron departed on a routine training flight and ran into a storm off the New Jersey coast. Due to a poorly designed altimeter which was overly sensitive to low barometric pressure, the crew of the ship literally flew the Akron into the sea, believing themselves to be at 800 feet when they were actually at 0 feet. Water quickly flooded the vessel and only three men survived out of the 76 on board at the time. One of the men killed was Rear Admiral William Moffett, the prime advocate and tireless promoter of the value and necessity of naval airships. His passing marked the beginning of the end of the US Naval Airship program, and although the Akron's already-constructed sister ship USS Macon made her maiden voyage just three weeks later, America would never again build a rigid airship.