The spy gondola, spy basket, observation car or sub-cloud car is a crewed vessel that an airship hiding in cloud cover could lower several hundred metres to a point below the clouds in order to inconspicuously observe the ground and help navigate the airship. It was a byproduct of Peilgondel development. They were used almost exclusively by the Germans in the First World War on their military airships.
Observatory car drawing from a December 1916 Scientific American cover
Juray fish-shaped spy gondola while crewed
An aeroplane photographed this spy basket in operation hanging from the American USS Macon in 1934-09-27.
A spy basket preserved at the Imperial War Museum, which fell from the LZ 90 on 2 to 3 September 1916.
USS Akron (ZRS-4) was a helium-filled rigid airship of the U.S. Navy, the lead ship of her class, which operated between September 1931 and April 1933. It was the world's first purpose-built flying aircraft carrier, carrying F9C Sparrowhawk fighter planes, which could be launched and recovered while it was in flight. With an overall length of 785 ft (239 m), Akron and her sister ship Macon were among the largest flying objects ever built. Although LZ 129 Hindenburg and LZ 130 Graf Zeppelin II were some 18 ft (5.5 m) longer and slightly more voluminous, the two German airships were filled with hydrogen, and so the two US Navy craft still hold the world record for the largest helium-filled airships.
USS Akron
Akron under construction in the Goodyear Airdock at Akron, Ohio in November 1930. Note the three-dimensional, deep rings.
Sample of the duralumin from which the frame of USS Akron was built
The maiden voyage of Akron on 2 November 1931, showing her four starboard propellers. The engines' water reclaiming devices appear as white strips above each propeller. The emergency rear control cabin is visible in the lower fin.