Saturday, June 13, 2009

The USS Macon

USS Macon (ZRS-5) was a rigid airship built and operated by the United States Navy for scouting. It served as a flying aircraft carrier, launching Sparrowhawk biplanes. In service for less than two years, in 1935 Macon was damaged in a storm and lost off California's Big Sur coast, though most of her crew were saved.

At less than 20ft (ca. 7m) shorter than Hindenburg, she and her sister, Akron, were among the largest flying objects in the world in terms of length and volume. Although Hindenburg was longer, the two sisters still hold the world record for helium-filled airships.
The USS Macon was built at the Goodyear Airdock in Akron, Ohio by the Goodyear-Zeppelin Corporation. The airship was named after the city of Macon, Georgia, which was the largest city in the Congressional district of Representative Carl Vinson, the then chairman of the House of Representative's Committee on Naval Affairs.

The Macon was christened on March 11, 1933 by Jeanette Whitton Moffett, wife of Rear Admiral William A. Moffett, Chief of the US Navy's Bureau of Aeronautics. The airship first flew one month later, shortly after the tragic loss of her sister ship, Akron (ZRS-4). Macon was commissioned on June 23, 1933 with Commander Alger H. Dresel in command.

The Macon had a structured duraluminum hull with three interior keels. The airship was kept aloft by 12 helium-filled gas cells made from gelatin-latex fabric. Inside the hull, the ship had eight German-made Maybach, 12 cylinder, 560-horsepower gasoline-powered engines that drove outside propellers. The propellers could be rotated down or backwards to control the ship during take-off and landings. Designed to carry five F9C Sparrowhawk biplanes, Macon received her first aircraft on board July 6, 1933 during trial flights out of Lakehurst, New Jersey. The planes were stored in bays inside the hull and were launched and retrieved using a trapeze.

Early service history

Departing the East Coast October 12, 1933, Macon's homefield became NAS Sunnyvale (now Moffett Federal Airfield) in Santa Clara County, California. Macon had a far more productive career than its sister ship, Akron. Macon's commanders developed the doctrine and techniques of using its airplanes to do scouting while the airship remained out of sight of the opposing forces in exercises. Macon participated in several fleet exercises, though the men who framed and conducted the exercises lacked an understanding of the ZRS's capabilities and weaknesses. It became standard practice to remove the F9C-2 fighter's landing gear aboard the airship and replace it with a fuel tank, giving the aircraft 30% more range.

Later in 1934, Lt. Commander Herbert Wiley surprised President Franklin D. Roosevelt (and the Navy) when Macon searched for - and located - the heavy cruiser USS Houston, which was then carrying the President back from a trip to Hawaii. Newspapers were dropped to the President on the ship, and the following communications were sent back to the airship: "from Houston: 1519 The President compliments you and your planes on your fine performance and excellent navigation 1210 and 1519 Well Done and thank you for the papers the President 1245."
The commander of the Fleet, Admiral Joseph M. Reeves, was upset about the matter - however, Commander of the Bureau of Aviation, Admiral Ernest J. King, was not. Wiley was soon promoted to Commander.

Leading up to the crash

During a crossing of the continent, Macon was forced to fly up to 1800 m (6,000 ft) to clear mountains in Arizona. As the ship's pressure height was less than 900 m (3,000 ft), a large amount of helium was vented to reach this altitude without rupturing the gas cells. To compensate for the loss of lift, 4 tonnes (9,000 lb) of ballast and 3 t (7,000 lb) of fuel had to be dumped. Macon was being flown 15,000 pounds 'heavy' and was operating at full power not only in order to have sufficient dynamic lift, but to have enough control to fly in the severe turbulence through a mountain pass near Van Horn, Texas. Following a severe drop, a diagonal girder in ring 17.5, which supported the forward fin attachment points, failed.

Rapid damage control by Chief Boatswain's Mate Robert Davis repaired the girders before further failures could occur. Macon completed the journey safely but the buckled ring and all four tailfins were deemed in need of strengthening. The appropriate girders adjacent to the horizontal and lower fins were repaired, but the repair to the girders on either side of the top fin were delayed until the next scheduled overhaul when the adjacent gas cells could be deflated.


On February 12, 1935 the repair process was still incomplete when, returning to Sunnyvale from fleet maneuvers, Macon ran into a storm off Point Sur, California. During the storm, she was caught in a wind shear which caused structural failure of the unstrengthened ring (17.5) to which the upper tailfin was attached. The fin failed to the side and was carried away. Pieces of structure punctured the rear gas cells and caused gas leakage. Acting rapidly and on fragmentary information an immediate and massive discharge of ballast was ordered. Control was lost and, tail heavy and with engines running full speed ahead, the Macon rose past the pressure height and kept going until enough helium was vented to cancel the lift. It took her 20 minutes to descend from 4,850 ft and, settling gently into the sea, Macon sank off the California coast. Only two crewmembers from her complement of 76 died, thanks to the warm conditions and the introduction of life jackets and inflatable rafts after the Akron tragedy.

The two that perished did so needlessly: Radioman 1 class Ernest Edwin Dailey jumped ship after it had lost most of its altitude but was still high above the ocean surface; Mess Attendant 1 class Florentino Edquiba drowned while swimming back into the wreckage to try to retrieve personal belongings. The cause of the loss was operator error following the structural failure and loss of the fin. Had the ship not been driven over pressure height (where the cells were expanded fully and lifting gas released) Macon could have made it back to Moffett Field.

Macon, having completed 50 flights from her commissioning date, was stricken from the Navy list on February 26, 1935. Subsequent airships for Navy use were of a nonrigid design.

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