Macon

black and white image of airship tethered on land and person walking in foreground — USS *Macon* ZRS-5 attached to its mooring mast. The airship’s stern section was attached to a rail system on the airfield so the ship could weathervane, or move with the wind direction. Photo: Wiley Collection, Museum of Monterey.

General Information and History

The USS Macon, a 785-foot dirigible, was lost offshore of Point Sur on February 12, 1935 when it foundered tail first into the chilly waters of the Pacific Ocean. For decades, its underwater location remained a mystery. In 1990 and 1991, the Monterey Bay Aquarium Research Institute (MBARI) and the U.S. Navy located Macon's remains at a depth of over 1,000 feet.

In 2005, a team of scientists onboard the NOAA research vessel McArthur II conducted a side scan sonar survey in Monterey Bay National Marine Sanctuary at the wreck site of USS Macon.

In 2006, researchers from Monterey Bay National Marine Sanctuary, Channel Islands National Marine Sanctuary, NOAA’s Office of National Marine Sanctuaries, MBARI, Stanford University, Moss Landing Marine Laboratories, and University of New Hampshire revisited the wreck site.

In 2015, NOAA's Office of National Marine Sanctuaries partnered with the U.S. Naval History and Heritage Command and Ocean Exploration Trust in collaboration with OceanGate Foundation to archaeologically survey the wreck site of this "flying aircraft carrier" and its four Curtiss Sparrowhawk biplanes. The survey was conducted from E/V Nautilus, and streamed live on the Nautilus Live website.
Learn more about the 2015 expedition to Macon

The remains of the Macon assemblage provide an opportunity to study the relatively undisturbed archaeological remnants of a unique period of aviation history. These remains are a significant resource both for the U.S. Navy and for Monterey Bay National Marine Sanctuary. Dirigibles were an important development in the history of aviation. There are no known existing examples of these craft that can be studied on land. While there is one known example of a Curtiss Sparrowhawk in existence, it is a composite biplane built from the parts of the last two surviving F9C-2s. Future aviation historians and the public will benefit from the comprehensive documentation and management of these craft.

Wreck of USS Macon Added to National Register of Historic Places

Commemorating the 75th anniversary of the loss of the U.S. Navy airship USS Macon, the wreck site and remains on the seafloor within Monterey Bay National Marine Sanctuary, were added to the National Register of Historic Places in February 2010. The National Register of Historic Places is the Nation's official list of cultural places considered worth preserving. The National Register listing provides additional federal protection for the wreck site and the artifacts there. Properties listed in the National Register can qualify for Federal grants for historic preservation.

"Dirigibles were an important development in the history of aviation and the Macon's remains represent the only archaeologically-documented example of such aircraft in the United States and possibly the world," said Bruce Terrell, senior archaeologist, NOAA Office of National Marine Sanctuaries Maritime Heritage Program. The wreck of USS Macon is the second site in Monterey Bay National Marine Sanctuary to be included on the National Register, administered by the National Park Service. The wreck of the California Gold Rush side-wheel steamship Tennessee was listed in 1981.

The Era of Dirigible Disaster

The U.S. Navy conducted a lighter-than-air aviation program between 1921 and 1935, using large dirigibles as fleet scouts. A problematic balance between needing to be lightweight and needing structural integrity plagued the history of U.S. Navy dirigible design.

The Marvel of the USS Macon

The USS Macon and its 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 crewmen 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 lifted back into the dirigible. Sparrowhawk pilots were called the "men on the flying trapeze" due to their mid-air maneuvers.

Marvelous USS Macon Facts (modified, with permission, from the Moffett Field Historical Society)

Macon, unlike the blimps made today, had a structured duraluminum hull with three interior keels. The intent of the strong spine was to prevent a hull collapse. From the outside it looked and functioned much like a large blimp. On the inside, the ship was an open cavern of girders, cables and catwalks with few places where the crewmen could not go.
Macon was 785 feet long, just 97.5 feet shorter than the RMS Titanic and over four times the length of today's Goodyear blimps.
When carrying Sparrowhawks and personnel, Macon weighed more than 400,000 pounds or the equivalent of two 100-ton blue whales.
Macon had accommodations for 100 officers and men, including sleeping berths, a large mess room, a galley, and observation platforms at the nose and tail.
Macon and its sister ship, Akron, were kept aloft by non-flammable helium contained in 12 large cells inside the craft. The German airship Hindenburg was kept aloft by hydrogen, a more flammable gas than helium, and burst into flames on May 6, 1937.
Macon needed 6.5 million cubic feet of helium to become airborne. This is roughly equivalent to 216,666 bathtubs (measuring 5 feet by 3 feet by 2 feet) full of air.
Macon could fly at a top speed of 80 miles per hour. Flying at top speed, it would take over 37 hours for Macon to cross the United States.
Macon had eight large 560-horsepower gasoline powered German built Maybach reversible engines driving outside propellers. Macon's propellers could be rotated down or backwards to control the ship during take-off and landings.
Macon was housed at Moffett Field in Sunnyvale, California in 1934 and 1935. During its 16-month stay, Macon became a familiar and popular sight.

black and white image of three biplanes flying above airfield — Curtiss Sparrowhawk F9C-2 biplanes flying over Hangar One at Moffett Airfield in Sunnyvale, California. At the time of the loss of the USS *Macon*, four of the five Sparrowhawks assigned to the airship were lost. Photo: Wiley Collection, Museum of Monterey.

black and white image of biplane and pilot flying above airfield — Curtiss Sparrowhawk F9C-2 fighter flying over Naval Air Station Moffett Field, California, in 1934. This plane was assigned to USS *Macon* ZRS-5. Photo: Wiley Collection, Museum of Monterey.

black and white image of insignia on side of biplane of two men on flying trapeze — Lieutenant Commander Herbert Wiley is credited for designing the emblem painted on the Sparrowhawk’s fuselage depicting the “men in the flying trapeze.” The larger person represents the airship, while the smaller person represents the Sparrowhawk. Photo: Wiley Collection, Museum of Monterey.

black and white image of 21 seated and standing naval officers in uniform — U.S. Navy officers serving on board the USS *Macon* ZRS-5. Photograph taken in Monterey, California circa 1935. Lieutenant Commander Herbert Wiley is seated in the front row center. Photo: Wiley Collection Museum of Monterey.

The Underwater Discovery of the USS Macon

In June of 1990, Chris Grech (retired) from the Monterey Bay Aquarium Research Institute (MBARI) coordinated with the U.S. Navy's three-man deep submergence vehicle Sea Cliff, to locate and document Macon's remains. During the dives, Sea Cliff recovered several artifacts from the site, and collected a definitive image of a Sparrowhawk arrester hook.

color image mosaic of three biplanes resting on ocean floor — Photomontage of Sparrowhawk biplanes from USS *Macon* wreckage, created by the staff of National Geographic Magazine using footage from ROV *Ventana*. Photo: © 1991 National Geographic Society (Image originally used in January 1992 issue of National Geographic).

MBARI returned to the site in February and April of 1991 and videotaped the site using a remotely operated vehicle (ROV). The team located debris fields that included corroded girders, gasoline tanks, the nose-mounted mooring assembly, and the dirigible's German-made Maybach engines. The control car was also located. Although it was flattened, MBARI was able to record windows, chairs, chart tables, and a lead pencil. Four of the Curtis F9C-2 Sparrowhawk biplanes were also located revealing their aluminum frames along with some deteriorated wing fabric still intact. The 1990/1991 surveys recorded the bow and mid-section debris fields. During these survey missions MBARI worked with the Navy to collect and distribute artifacts including the arrester hook from a Sparrowhawk. This artifact was conserved at East Carolina University.

The Mystery of the Submerged Remains of the USS Macon

The exact location of the submerged remains of the USS Macon remained a mystery for nearly 50 years until a commercial fisherman snagged a piece of girder from Macon in his net. The girder was displayed in a Moss Landing seafood restaurant on a plaque presented to the restaurant owners by the fisherman who had recovered the piece. Marie Wiley Ross noticed the girder structure. She had seen airship girders like this one as a child with her father, Lt. Comdr. Herbert V. Wiley, who commanded the USS Macon. Wiley, who was in command of the airship at the time of its loss, had also survived the loss of the USS Akron, Macon's sister-ship. Scientists were unaware of Marie's discovery until 1989.

In 1988 the first attempt to locate Macon using side scan sonar proved she was not lying at her recorded sinking location. This initial effort spawned the interests of Dick Sands of the National Museum of Naval Aviation Foundation in Pensacola, Florida as well as David Packard, founder of MBARI. They asked Chris Grech, an ROV pilot for MBARI, who participated in the search for Macon in 1988, to head up another expedition to the site.

During the 1989 exploration to locate Macon led by Grech and MBARI, Gordon Wiley (Marie Wiley's brother, also the son of Herbert V. Wiley who commanded Macon) mentioned that the girder from Macon was mounted on a wall in a Moss Landing restaurant.

Grech and Dick Sands were able to follow up on this new lead through a month-long investigation tracing the roots of origin of the Macon artifact on display at the restaurant. This sleuth work revealed Macon's actual location.

2005 Expedition to the USS Macon

In 2005, a team of scientists conducted a side-scan sonar survey of the USS Macon wreck site in Monterey Bay National Marine Sanctuary to record the extent of the debris field in preparation of the remotely operated vehicle survey in 2006.

schematic diagram of sonar equipment towed above seafloor — Schematic diagram of a sidescan sonar towed instrument insonifying the seafloor (top) and the sidescan data record created (bottom). The intensity of sound reflected back from rocks, sediment and other features provides information on the distribution and characteristics of the seafloor morphology. Strong reflections (high backscatter) from boulders, gravel, and positive topographic features facing the instrument are white and weak reflections (low backscatter) from finer sediments and shadows are in black. Photo: U.S. Geological Survey

scientists deploying sonar equipment from aft deck of ship — A side scan sonar tow fish is being deployed off the back deck of NOAA research vessel *McArthur II*. Photo: Robert Schwemmer/NOAA

sepia tone side-scan image of debris on seafloor — Side-scan image of one of the major debris fields of the USS *Macon* that includes four Curtiss F9C-2 Sparrowhawk aircraft. Photo: Robert Schwemmer/NOAA

2006 Expedition to the USS Macon

The overarching goal of this mission in 2006 was to conduct comprehensive documentation of the USS Macon wreck site that can be used to evaluate the archaeological context of the craft. This allowed NOAA's National Marine Sanctuary Program (now the Office of National Marine Sanctuaries) and the Naval Historical Center to determine the condition of the site, the level of preservation of the archaeological remains, and the potential for research at the site.

Working in collaboration with the Monterey Bay Aquarium Research Institute (MBARI), researchers utilized MBARI's 117-foot (35.66 meter) research vessel Western Flyer, a small waterplane-area twin hull oceanographic ship. The vessel provides a stable platform for deploying, operating, and recovering a tethered remotely operated vehicle (ROV) and capable of working at the required depth of the Macon site.

The ROV Tiburon (retired), deployed from the Western Flyer, has a maximum working depth of 13,123 feet (4000 meters). Tiburon is equipped with adjustable high-definition video cameras and coordinated lighting. A high-resolution video camera system was configured for this mission by Stanford University to be used in conjunction with an ROV control system. The ROV was also equipped with imaging sonar, which was key to maneuvering around the wreck site to avoid entanglement and scan the sea floor for further debris fields.

Over the course of a five-day archeological investigation in September 2006, researchers from NOAA's Office of National Marine Sanctuaries, MBARI, University of New Hampshire, and Stanford University conducted deepwater surveys (more than 40 hours of video) using MBARI's ROV Tiburon.

The first goal of the expedition was to maneuver ROV Tiburon above the wreck site and systematically record the visual remains of the airship and aircraft through high-definition video and high-resolution still photography. The imagery was used to create a photomosaic of the two major debris fields. The photomosaic l provides a visual reference of the full magnitude of the wreck site and assists in the site characterization and interpretation as well as imagery for education and outreach efforts.

Researchers documented two major debris fields associated with the submerged wreck site. The two debris fields, designated by scientists as debris fields A and B, are separated by a distance of 250 meters, measure 60 meters in diameter, and are elevated several meters above the seafloor. Several centimeters of sediment were deposited on wreck artifacts, including the wings of the Sparrowhawk biplanes.

The second goal of the expedition was to record in more detail specific artifacts utilizing Tiburon's still camera, video zoom, pan/tilt cameras, and precession parallel laser system for measuring, including examination of the aluminum structural remains of the airship and aircraft. Scientists concluded that sections of the aluminum girder show signs of degradation after 71 years in the marine environment. An analysis will be conducted to compare the 2006 visual record to the site documentation in 1990/91. This may provide important data on the rate of degradation of aluminum in a deep sea, saltwater environment.

Distinguishable features found in debris field A included the airship's hangar bay containing four Sparrowhawk biplanes and their detached landing gear. Five of Macon's eight German-built Maybach 12 cylinder gasoline engines also were identified. Objects from the ship's galley were found, including two sections of the aluminum stove, propane tanks that supplied fuel for it, and the enlisted men's dining table and bench. Debris field B contained Macon's bow section including the mooring mast receptacle assembly. This field also contains aluminum chairs and desks that may have been in a port side officers' or meteorologist's office.

A third goal of the expedition was to conduct a biological survey. Video footage and images from the 1991 survey of the USS Macon indicate the submerged remains serve as an artificial reef in the deep sea. To characterize the habitat and species composition associated with the wreck (and surrounding area), megafaunal invertebrates and fishes were identified using the digital video and still cameras on ROV Tiburon. The biological survey characterized species that occurred on wreck debris (hard substrates) in deep water and will add to the body of knowledge for management and protection of sanctuary resources.

The expedition was designed to build upon information gathered by the U.S. Navy and MBARI, who first recorded the aircraft's remains during expeditions in 1990 and 1991. An initial survey involving NOAA, MBARI, U.S. Geological Survey, and Moss Landing Marine Laboratories was completed in May 2005 utilizing side-scan sonar deployed from the NOAA research vessel McArthur II.

Both phases of the survey contributed to mandates of the National Historic Preservation Act (which directs federal programs managing public lands to survey and inventory historical and archaeological properties and nominate them to the National Register of Historic Places) and the National Marine Sanctuaries Act (which directs the Monterey Bay National Marine Sanctuary to manage and protect archaeological resources such as the Macon site). This expedition aided in the assessment of the USS Macon and four Curtiss F9C-2 Sparrowhawk aircraft for eligibility to the National Register of Historic Places.

The expedition was a collaborative venture involving NOAA's Office of National Marine Sanctuaries, NOAA's Office of Exploration, NOAA's Preserve America Initiative, MBARI, Stanford University, University of New Hampshire, U.S. Navy, state of California, Monterey Maritime and History Museum, and Moffett Field Historical Society and Museum. Noah Doughty, an educator from Mission College Preparatory High School in San Luis Obispo, Calif., participated as a NOAA "Teacher-at-Sea" and provided daily science and technology web-based logs.

2006 Expedition Media Gallery:

color image of research vessel on calm ocean with mountains in background — MBARI’s 117-foot water-plane area twin hull (SWATH) R/V *Western Flyer* served as the research platform for scientists during the USS *Macon* expedition. Photo: R. Schwemmer/NOAA.

remotely operated vehicle inside research vessel being retrieved from ocean with crane — MBARI's ROV *Tiburon* being recovered in the moonpool on board the R/V *Western Flyer*. The uncrewed submarine is launched and recovered through two folding doors located between the *Western Flyer*'s two hulls. The ROV can dive to 4,000 meters (about 2.5 miles) depth, and is controlled using a very long cable, which also transmits data and video images back to the ship. The brightly colored upper portion of the ROV is constructed of incompressible foam, whose buoyancy makes the 3.5 ton ROV nearly weightless in seawater. Photo: R.Schwemmer/NOAA.

three scientists pointing at paper poster hung on wall — Co-Principal Investigators (left to right) Robert Schwemmer (NOAA), Chris Grech (MBARI), and Bruce Terrell (NOAA) examine draft photomosaic. Photo: E. Burton/NOAA.

underwater color image of damaged biplane wing resting on seafloor — Submerged view of the port wing of one of the four Curtiss Sparrowhawk F9C-2 biplanes recorded at the USS *Macon* site in 2006. The U.S. Navy star is still visible 71 years after the loss of the airship and four biplanes. Photo: NOAA/MBARI.

underwater color image of damaged biplane cockpit on seafloor — Curtiss Sparrowhawk F9C-2 cockpit with telescopic gun site located in center of fuselage above cockpit. Photo: NOAA/MBARI.

underwater color image of biplane skyhook on seafloor — Submerged view of the “skyhook” located at the center of one of the Curtiss Sparrowhawk F9C-2 biplanes. Sparrowhawk pilots were nicknamed the "men on the flying trapeze." Photo: NOAA/MBARI.

underwater color image of engine on seafloor — Submerged view of one of eight German-built Maybach 12-cylinder gasoline engines located on the seafloor. The spark plug wires are still clearly visible, assisting the science team in verifying the number of cylinders. During the 2006 expedition five Maybach engines were located and recorded. Photo: NOAA/MBARI.

underwater color image of damaged airship parts on seafloor with fishes and seastar — Submerged view of the USS *Macon*’s mooring mast receptacle assembly, the most forward part of the airship and possibly the last section of the ship to sink. The tapered cone would mate up with the land-based mooring mast. Photo: NOAA/MBARI.

underwater color image of upside down desk drawers on seafloor and fishes — Inverted desk drawers with handles, possibly from the officers' or meteorologist's office located on board the port side of the USS *Macon*. Splitnose rockfish (*Sebastes diploproa*) and thornyheads (*Sebastolobus* sp.) use the wreck site as habitat. Photo: NOAA/MBARI.

2015 Expedition to the USS Macon

In August 2015, NOAA's Office of National Marine Sanctuaries worked with the U.S. Naval History and Heritage Command and Ocean Exploration Trust in collaboration with OceanGate Foundation to archaeologically survey the wreck site of the USS Macon and its four Curtiss Sparrowhawk biplanes.

This project's primary goal was to provide ongoing stewardship of the wreck site by updating site documentation to supplement previous years' surveys. The Monterey Bay National Marine Sanctuary Management Plan emphasizes the systematic assessment and monitoring of archaeological resources as a sanctuary priority. The USS Macon site contains some of the oldest known aviation material submerged in saltwater in the US. Since the discovery of the submerged remains of the Navy dirigible USS Macon in 1990, NOAA and Monterey Bay National Marine Sanctuary have designated personnel to develop a program to document its archaeological resources through survey and sampling. The USS Macon site was assessed and deemed eligible for the National Register of Historic Places in 2006, and was listed in 2010.

The secondary goal was to study and benchmark site formation processes for an early modern-metals aviation site. Despite its age and marine organism activity, the metal and organic remains of the aircraft appear to retain a high level of integrity. A detailed study of the site formation processes, along with a sample comparison to 1991 sampled metal, informed general archaeological knowledge of the potential longevity of aviation sites in deep water.

This survey's documentation methods included creating an updated site map photomosaic, on-site photography and video, post-survey 3D modeling, and materials and samples study.

To learn more about the 2015 expedition, see the Office of National Marine Sanctuaries Expedition page.