The USS Macon

Career (United States)
Name:	*USS Macon* ZRS-5**
Launched:	21 April 1933
Commissioned:	23 June 1933
Struck:	26 February 1935
Fate:	Crashed following structural failure on 12 February 1935.
General characteristics
Class and type:	Airship
Tonnage:	108 t
Length:	239 m (785 ft)
Beam:	40.5 m (132.8 ft) (diameter)
Height:	44.6 m (146.2 feet)
Propulsion:	8 internal combustion engines 420 kW each
Speed:	140 km/h (75.6 knots 87 mph) maximum
Capacity:	Useful load 72 t Volume 184,000 m³
Complement:	91
Aircraft carried:	five F9C biplanes

USS Macon (ZRS-5) was a rigid airship built and operated by the United States Navy for scouting. In service for less than two years, in 1935 Macon was damaged in a storm and lost off the coast of California. At less than 20ft (ca. 7m) shorter than Hindenburg, she and her sister, Akron, were among the biggest flying objects in the world. Although Hindenburg was longer, the two sisters still hold the world record for helium-filled airships.

She was built in Springfield Township, Ohio by the Goodyear-Zeppelin Corporation, christened on March 11, 1933 by Jeanette Whitton Moffett (wife of Rear Admiral William A. Moffett), and first flew one month later, only a few weeks 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.

Macon had 12 helium-filled gas cells made from gelatine-latex fabric. 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. Departing the East Coast October 12, 1933, Macon's homefield became NAS Sunnyvale (now Moffett Federal Airfield). 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. Lt. Commander Herbert Wiley surprised the President, and the Navy, when Macon searched for and located USS Houston, carrying the President back from a trip to Hawaii. Newspapers were dropped to the President and the following communications were sent: 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 most upset; Commander of the Bureau of Aviation, Admiral Ernest J. King,^[1] was not. Wiley was soon promoted to Commander.

Leading Up To The Crash

Click on Picture to enlarge

USS Macon over Moffett Field

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 tones (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.

The Disaster

Click on Picture to enlarge

USS Macon flies over New York City.

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 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.

Exploration Of the Wreck Site

The Monterey Bay Aquarium Research Institute (MBARI) succeeded in locating and surveying the debris field of the Macon in February 1991, and was able to recover artifacts from it.^[2] The exploration included sonar, video, and still camera data, as well as some artifact recovery.

In May 2005 MBARI returned to the site as part of a year-long research project to identify archeological resources in the bay. Side-scan sonar was used to survey the site.

The 2006 Expedition

A more complete return with including exploration with remotely operated vehicles took place in September 2006, which included researchers from MBARI and from NOAA, the National Oceanic and Atmospheric Administration's Office of National Marine Sanctuaries.^[3] Video clips of the expedition were made available to the public through the OceansLive Web Portal, a service of NOAA.

The 2006 expedition was a success, and revealed a number of new surprises and changes since the last visit, ~15 years ago. High-definition video and more than 10,000 new images were captured, which will be assembled into a photomosaic of the wreck.^[4]

Protection

The research team also hopes to use the new data to get the wreckage of the Macon listed on the National Register of Historic Places. The wreck site remains secret, and is within a marine sanctuary and is not accessible to divers due to depth. It is also a U.S. Navy gravesite.

References

Chief of Naval Operations during World War Two.

"MBARI's First Decade: A Retrospective" (PDF). Monterey Bay Aquarium Research Institute (ca. 1997). Retrieved on 2006-10-04. (page 11)

"Expedition To Probe Sunken Airship", KSBW-TV (September 13, 2006). Retrieved on 2006-10-04.

"USS Macon Exploration Findings Unveiled", KSBW-TV (September 27, 2006). Retrieved on 2006-10-04. (includes slideshow)

Robinson, Douglas H., and Charles L. Keller. "Up Ship!": U.S. Navy Rigid Airships 1919-1935. Annapolis, Maryland: Naval Institute Press, 1982. ISBN 0-87021-738-0

Richard K. Smith, The Airships Akron & Macon (Flying Aircraft Carriers of the United States Navy), United States Naval Institute: Annapolis, Maryland, 1965

Wikipedia

USS Macon, sister of the 6,500,000 cubic foot rigid airship Akron (ZRS-4), was built at Akron, Ohio. She first flew in April 1933, only a few weeks after Akron's tragic loss. Following a series of test flights, one of which took her from Ohio to Wisconsin and back, she was commissioned in June. Macon was based at Lakehurst, New Jersey, during mid-1933 and made several development and training flights during this time. In October she flew by way of her name city of Macon, Georgia, and Texas to Moffett Field, California, where a new airship hangar awaited her.

During the rest of 1933 Macon and her embarked airplanes began what would be an extensive program of participation in exercises off the Pacific Coast, testing her abilities for fleet scouting and other missions. In April 1934 she flew east, again via Texas, to Opa-locka, Florida. Weather damage received in this trip was repaired in time for her to participate in Fleet Problem XV in the Caribbean during May, after which she returned to Moffett Field. Macon made a long-distance flight over the Pacific Ocean in mid-July to intercept the cruiser Houston (CA-30), which was carrying President Franklin D. Roosevelt from Panama to Hawaii. During this mission her F9C "Sparrowhawk" aircraft were operated with their wheeled landing gear removed, a performance-enhancing practice that was thereafter normal when these small fighting planes were embarked on the airship.

Further fleet exercises followed over the remaining months of 1934 and the first part of 1935. These demonstrated Macon's ability, in association with her airplanes, to conduct strategic searching over the vast distances to be expected in a Pacific war. However, they also showed her vulnerability, especially in the presence of opposing airplanes, when she was used for tactical scouting close to the fleet. During the early evening of 12 February 1935, while returning to Moffett Field from an operation over the ocean, USS Macon encountered a storm off Point Sur, California. A violent gust tore off her upper fin, causing damage that soon brought her down into the sea. Though all but two of her crew were rescued, the dirigible sank in deep water, effectively ending the Navy's controversial, and trouble-plagued, program of rigid airship operations.

The USS Macon and her sister ship the USS Akron were designed and constructed by Goodyear-Zeppelin Corporation. Unlike today’s blimps, the dirigibles had sturdy frames and internal hulls. The USS Macon and USS Akron were called rigid airships because they were made of these rigid structures. These structures provided overall strength and tremendous access to interior portions of the dirigible. On the inside of the rigid airships, catwalks and girders allowed crewman to traverse the interior.

In addition to catwalks and girders, the USS Macon and USS Akron also had internal hangars located about two-thirds of the way behind the nose of the airship. The airships could launch and retrieve five aircraft through a T-shaped opening in the floor of the hangar. Launching and retrieving the planes was a miraculous feat! A welded metal hook called a “sky hook” was attached to the top of each plane and was used to attach the plane to a trapeze. The trapeze and plane were lowered through the hangar floor. Pilots then had to rev up their engine RPMs, yank a release lever, and drop into the air mid-flight.

For the dirigible to retrieve the planes, pilots had to match their speed to the dirigible and gently guide the small hook back onto the trapeze. The plane was the lifted back into the dirigible. Sparrowhawk pilots were called the “men on the flying trapeze” due to their mid-air maneuvers.

The Sparrowhawk planes operated as eyes for the large airships. More maneuverable and capable of greater speed than the dirigible, the planes could scout large areas allowing the dirigible to remain far from enemy fighter planes.

The Underwater Airship

The military zeppelin USS Macon was meant to be a floating American aircraft carrier over the Pacific Ocean -- but it crashed, sank and has been lying on the ocean floor for more than 70 years. Now scientists have discovered and documented the unique wreck off the coast of California.

The tragedy unfolded unusually slowly for an aviation catastrophe: The crew fought to control the USS Macon for more than an hour. US naval officers threw fuel canisters overboard in an attempt to reduce the weight of their vessel. The canisters imploded on their way to the ocean floor. Meanwhile, the Macon -- the largest rigid airship ever constructed in the United States -- sank inexorably downward, the safety of the Moffett Field hangar just within reach.

The Macon hit the water surface only five kilometers (three miles) off the Californian coast, along the latitude of the Point Sur lighthouse near Monterey, on Feb. 12, 1935. The zeppelin broke apart and sank into the deep water. Two of the 83 crew members died -- the low number of deaths is likely due to the fact that the Macon sank in slow motion.

Neither enemy fire nor sabotage was to blame for the giant airship's doom (and a giant it was: longer than three 747 jets parked nose to tail). A heavy storm above the picturesque stretch of Californian coast known as Big Sur tore off the Macon's vertical tail fin. The airship's structural framework was so badly damaged that the Macon broke apart when it hit the water.

A riddle at the bottom of the ocean

Click on Picture to enlarge

Why and how that happened is the question an interdisciplinary research team now wants to answer. While an investigative commission formed by the US Navy following the catastrophe was able to determine that shoddy repair work was to blame for the crash -- a test flight above Texas had led to damage to the structural framework earlier -- the results reached by the commission were never definitively proven. The commission's researchers had to content themselves with speculation -- after all, the evidence for their hypothesis lay 450 meters (1,476 feet) below the ocean surface. Scuba divers are still unable to reach that depth today, although treasure hunters and dealers in military paraphernalia are sometimes equipped to go there. However, the location of the wreck was kept secret precisely in order to prevent plundering.

It was only in June 1990 that Chris Grech, the deputy director of the Monterey Bay Aquarium Research Institute (MBARI) discovered the first pieces of wreckage on the ocean floor. Several high-tech searches had been unsuccessful during the 1980s. Grech finally discovered the Macon's remains in the middle of a deep-sea reservation area. Its existence is the only reason why what Grech calls a "unique time capsule from another era" has remained untouched for more than 70 years. If commercial fishing had been allowed in the area, dragnets would long since have destroyed the ghostly remains at the bottom of the ocean.

In late September of this year, scientists from MBARI and the National Oceanographic and Atmospheric Administration (NOAA) joined forces with the US Navy. They left Monterey on board the research ship Western Flyer in order to systematically survey the area. Until then, the scientists had to work with low-resolution sonar images of the wreckage, but now an underwater robot, the remotely operated vehicle (ROV) Tiburon, was able to explore the Macon's final resting site -- and take close-up pictures.

A chapter in the history of military technology

Click on Picture to enlarge

"The primary goal of the mission is to conduct comprehensive documentation of the site of the USS Macon's loss that can be used to evaluate the archaeological context of the craft," according to a NOAA statement. But the scientists are also secretly hoping to find the Macon's tail fin -- the part that turned out to be the weakest link in the construction, during the airship's final, ill-starred ocean flight.

Grech, the project's director, says he's noticed changes since his last visit. "A lot of the wreck is covered up," Grech told the New York Times. "It's easy for sediment to build up over time, and some large objects have moved."

Water currents along the Californian coast could pull the Macon's remains so far apart that they would become useless to historians. That's why the September expedition documented every detail of what it discovered, producing a mosaic of photographs. Paradoxically, the most easily recognizable objects on the photographs are the remains of four small Curtiss F9C-2 "sparrowhawk" fighter planes. The airship was intended to function as an airborne aircraft carrier -- an enormous, cigar-shaped vessel that would carry the small, agile biplanes much further into the airspace above the Pacific Ocean than they would ever have been able to venture themselves. The propeller-driven fighters were meant to fly reconnaissance flights above the ocean. As early as the 1920s, the US Navy was preparing for a war in the Pacific.

"The planes don't look damaged," Grech told the New York Times, pointing out that the wings of the planes are intact and that their bright yellow color and blue and white Navy star are visible. What is more, five of the Macon's giant Maybach engines can also be seen lying on the ocean floor off Point Sur, along with parts of the airship's canteen and the officer's quarters. An aluminium chair, a metal cabinet, a desk and several shelves offer insight into the interior design preferences of the 1930s military.

No tail fin, no corpses

Click on Picture to enlarge

The Macon consisted of a rigid framework made from aluminium alloy; the framework supported a canvas hull. Inside the hull, helium tanks ensured the overall construction was lighter than air. While the giant airship's overall weight was more than 200 tons, the lightness of its construction materials has turned out to be the very factor that poses special difficulties for today's underwater archaeologists.

Only two thirds of the wreck have been discovered and mapped, according to Grech. When they returned to the port of Monterey, the scientists had to face up to the fact that the Macon's missing tail fin -- the decisive component of the crashed airship -- has yet to be discovered. "It's either buried under sediment or in one of the canyons," Grech told the New York Times. Nor was any sign of the two victims of the crash discovered. Bruce Terrell, a marine historian at NOAA, told the New York Times that the researchers "had not seen any indication of human remains."

The loss of the USS Macon in 1935 marked the end of the US Navy's dirigible program, which already had a 20-year history then. The program had long been criticized for the high costs involved -- costs especially well exemplified by the USS Macon, the most expensive aviation object of its time. Following the Macon's crash, concerns about costs were compounded by security-related arguments, and the aviation program no longer seemed justifiable. And yet the airship the New York Times called the "high-tech wonder of its day" was off to a good start: The construction was considered especially safe, since it contained no flammable hydrogen, but only helium, which cannot explode.

Two years later, the most famous of all airship disasters demonstrated just how dangerous the use of hydrogen -- which is lighter and cheaper than helium -- can be: On May 6, 1937, the German airship LZ 129 Hindenburg caught fire on the Lakehurst airfield in New Jersey, where the USS Macon had been stationed for a brief period of time as well. Filled to the brim with hydrogen, the Hindenburg caught fire while landing on the airfield -- 36 of the 97 persons on board died. That day, military strategists lost whatever interest they may still have had in the use of airships for military purposes.

References

Wikipedia

DEPARTMENT OF THE NAVY -- NAVAL HISTORICAL CENTER

USS Macon: At 785 Feet Long,
Is Nearly as Large as the
Famous Graf Zeppelin

On April 21, 1933, the USS Macon, costing $2.5 million, left Akron, Ohio on its maiden voyage.

The Macon had accommodations for 100 officers and crew, including sleeping berths, a large mess room, a galley and observation platform at the nose and tail.

The Macon was kept aloft by non-burning helium contained in 12 large gelatin-latex cells inside the craft.

The Macon carried its own protection - five sparrow hawk fighter planes stored in the aircraft's belly.

The Underwater Airship

References

Wikipedia

DEPARTMENT OF THE NAVY -- NAVAL HISTORICAL CENTER

USS Macon: At 785 Feet Long, Is Nearly as Large as the Famous Graf Zeppelin

On April 21, 1933, the USS Macon, costing $2.5 million, left Akron, Ohio on its maiden voyage.

The Macon had accommodations for 100 officers and crew, including sleeping berths, a large mess room, a galley and observation platform at the nose and tail.

The Macon was kept aloft by non-burning helium contained in 12 large gelatin-latex cells inside the craft.

The Macon carried its own protection - five sparrow hawk fighter planes stored in the aircraft's belly.

The Underwater Airship

USS Macon: At 785 Feet Long,
Is Nearly as Large as the
Famous Graf Zeppelin