 Chapter 6 The Airship Flies Again, June to July, 1930 The two planes dove and ascended, twinning their smoke trails, orange and white, respectively, until they created an ephemeral Prince of Wales feather, the heraldic badge of the heir apparent. As the feather dissipated, R101 circled the Hinden airfield in north London, while Erwin awaited the cue for the ship to rehearse its role in the RAF display scheduled for the next day. He flew a revitalized ship, its lift increased by five tons, two tons from shaving more weight, three tons from enlarging the gas bags further, and with a patched together outer cloth cover. As R101 circled at an altitude of 1500 feet on this late June afternoon, the August tones of the RAF central band in the stands below occasionally wafted into the control car. But the music was often obscured by the growl of planes. First interceptor fighters zoomed by at an astonishing 200 miles per hour, then nine acrobatic biplanes swooped over the airfield. They split into groups of three, each group linked by elastic ropes. The planes came astonishingly close, while flying at 150 miles per hour, crisscrossing to create with the ropes a colossal pendant in the sky. Their nimble maneuvers highlighted R101's stately majesty as it hovered in the blue summer sky. Once the biplanes departed, Irwin received the cue for R101 to fly over the airfield. Irwin ordered the rudder coxswain to swing R101 around until its nose pointed toward the airfield. R101's engines roared and the mighty airship searched forward. Today Irwin commanded R101 without his friend and trusted first officer Noel Atherston. Atherston was detailed to Canada to lead the relief crew for the soon to depart R100, the sibling airship assigned to Pioneer Atlantic Crossings. Although Irwin missed Atherston, he was relieved to be without the medals of Major Scott. He was on the Canada flight as well. Irwin ordered the elevator coxswain to execute a shallow dive to imitate a bow to the royal box. The viewing stands were empty today, but would be full tomorrow. The coxswain nudged his wheel to start a gentle dive, but the ship dove sharply toward the ground. The quick thinking coxswain spun the elevator control wheel to reverse the direction of the elevators, but R101 continued its descent. The ship dropped in a few seconds 1,000 feet, until about 500 feet from the ground, its nose rose and the ship glided over the back of the stands as it climbed to 1,500 feet. The dive shocked the control car crew, alert now for further unusual motions of the ship. On its return to the works, R101 chopped to the air, its nose again and again descending than rising, and Irwin struggled to keep the ship above 1,000 feet. He knew, of course, that the lift changed based on fuel consumption and the air temperature, which caused the hydrogen to expand or contract, but still the ship's erratic flight was unusual. Although R101 guzzled two tons of fuel on its flight, Irwin had to drop nine tons of ballast before landing. He attributed the ship's heavy flying to the weather. The day of the RAF display, temperatures reached 70 degrees Fahrenheit, and through the sparse clouds, the sun baked R101's outer cover for more than 12 hours. The pale redheaded Irwin was always aware of the sun. He knew it heated the hydrogen in the gas bags and caused them to swell, which increased the lift by as much as five tons. This was not an uncommon problem for airships. The Graf Zeppelin had overheated only a week earlier. It had landed on the ground in Hamburg, the Germans preferred ground landings to mooring towers, and the captain and first officer had stepped off the ship to greet the crowd of 25,000, which included the Senate of the Free State of Hamburg while wearing formal dress. As the town's mayor presented the captain with an engraved cup to commemorate the first landing of a Zeppelin in Hamburg, the stern of the airship rose, the ship almost standing on its nose. The second officer, still in the ship, ordered ballast dropped and the engine started. He righted the ship, but its buoyancy increased by the heating of its gas bags and could not land again. He returned the ship to Berlin, where the cooler night air decreased the ship's lift and allowed it to land. To Irwin, this phenomenon explained not only R101's rapid rises, but also its abrupt descents. The heat enlarged the gas bags so much that the automatic valves perched hydrogen to prevent the bags from bursting. This cycle of expanding and purging repeated throughout the day. The next day, R101 returned to Hinden airfield and awed 150,000 spectators with a spectacular entrance. The ship hid behind a cloud and on cue flew low and slow over the airfield. On Irwin's orders, it executed the rehearsed bow to Prince George, the future Duke of Kent, who set with Prince and Princess Takamatsu of Japan. On route, R101 had behaved well, but on the return to the works, the ship repeatedly dove sharply. After each dive, the coxswain angled the elevators to force R101 to creep back to its proper altitude. It is as much as I can do to hold her up, sir, said the exhausted coxswain, his face streaming with sweat, sweating blood, recalled an observer. The moment the coxswain leveled the ship, it dipped again. The crew suggested to Irwin that it was bent, their term for a heavy airship. They recommended that he drop ballast. Irwin rejected this. Better, he said, to keep the ballast for landing. Turbulent air, he thought, caused R101's instability. When R101 arrived at the tower, Irwin jettisoned to more than eight tons of ballast to lighten the ship enough for mooring. He now worried that R101 leaked hydrogen. Perhaps the seals around the automatic valves had loosened. When the ship was moored, he planned to investigate the gas bags and the valves. The ship's gas bags are the least satisfactory part of R101, declared the ship's chief designer. Adding that development and improvement of the bags is badly needed. In their five years of planning R101, he and his staff searched for the perfect gas bag material, something impermeable to hydrogen, lightweight, flexible, yet durable. They considered the Varney silk or cambrick used in balloons, but these fabrics weighed too much. So they investigated rubber, gelatin and glycerin, and viscose, a synthetic fabric covered with latex. All failed. When crumpled and inflated, each of these materials cracked and leaked. So they settled for the traditional material used to construct airship gas bags, the intestines of oxen. The outside of an oxen's intestine is lined with a fine membrane called the cecum, which is thin and flexible, and through which hydrogen seeps only slowly. It's an ideal material for a gas bag, except for its size. The cecum of an ox is about 30 inches by six inches, a little over a square foot. Yet one of R101's gas bags, when spread flat, covers 30,000 square feet, a square about 175 feet on a side. So to create a gas bag, constructed from a double layer of cecum, coals for 50,000 entrails. In total, over a million and a half oxen and testines were needed to create R101's 15 gas bags. The gristly work of fabricating the gas bags was done by the women of the Royal Airship Works, almost all the labor at the works was local, what one aviation expert called Bedfordshire Yokels, although he noted they are extraordinarily good workers and well disciplined. To start construction of a gas bag, the women first unpacked oxen entrails shipped in barrels from Argentinian slaughterhouses. In a room reeking of awful, they soaked the intestines to remove the salt crystals used as preservative in transit, scraped away lumps of fat with blunt knives, soaked the skins overnight, and then scraped again. Next, they placed the skins on a huge roll of canvas stretched top and bottom between two rollers, tilted at 50 degrees like an easel. 20 women standing a shoulders width apart, each laid down two layers of skins on the canvas in front of them, and then on cue, they rolled the canvas to flatten the skins and expose a new blank section of canvas to work on. They repeated this until they fused about 25,000 skins into a single, continuous sheet with the weight and texture of parchment. Next, they moved the giant rolls to the gluing room. In the oppressive, mothball-like odor of the creosote-based glue, they unfurled the canvas, peeled off the thin skins, smoothed them like tablecloths over large tables, and clamped them taut. On the taut skins, they glued cotton fabric. The gluing room then filled with the odor of formaldehyde as the women coated the cotton skin composite with a waterproofing varnish. After this, the skins were moved to the large floor of the humid assembly room, maintained at 80% humidity to keep the skins pliable, where the women laid out the cotton skin layers on the floor to create the vast surface of a gas bag. They used two of the rolled sheets worth of skins for the smallest bags, but eight or so for the largest bag, which covered nearly three acres. Once the delicate sheets were laid out, the women sandpapered the edges of each sheet and glued them together to form a flayed and flattened gas bag. After cutting a hole for the gas valve, they wrapped this vast sheet around a cotton form in the shape of a gas bag, a shape maintained by an air blower. They glued shut the remaining seams, deflated the cotton form, and removed it through the valve hole. The glue improved on the sewing technique used to construct zeppelin gas bags because gluing left no needle holes that could leak. After construction, the deflated gas bags lay on the floor, a mass of folds large enough to hold 37,500 cubic feet of hydrogen, a sphere with a radius of 20 feet, yet weighing only 30 pounds. Soon it would be transported to R101, inserted into the metal framework, and inflated with care because the bag cost over 8,000 pounds, or 10 times the price of a house in a London suburb in 1930. After R101 returned from the RAF display, Erwin investigated the gas bags and their embedded automatic gas valve. To do this, he climbed from the walkway into the bag area. The gas bags formed at off-white ceiling, 10 feet or so above the walkway. His inspection of the seals on the first three bags uncovered no problems. When he reached the fourth, he climbed a small ladder, then grabbed the wire netting that tethered the gas bag to the ship's stainless steel and a Rallium and Framework. He lifted himself onto the bag, a small flashlight dangled from his neck. Although electrical lights illuminated the walkway, the gas bags above were always dark, even dank. The odor of mold permeated the air. After months in the dark, the animal intestine gas bags often rotted. Erwin used the netting, like a jungle gym, to climb across the gas bag's vast surface, the toll man so insignificant on the bag that he looked like a fly in an enormous spider's net. The delicate gas bags were fragile. Less than a year earlier, a rigor had slipped and punctured one with his foot. So as he climbed, Erwin gently parted the area where the neighboring gas bags touched. The giant bags muffled all sound, yet in that echo-less atmosphere he sang, talked and whistled as he climbed, hoping that if he reached a pocket of escaped hydrogen, his voice would become high-pitched or his whistle shrill. Hydrogen is odorless, colorless, and tasteless, so it affixiates without warning, and more than one unconscious worker had plunged to his death while working inside an airship. When Erwin reached the valve, he ran his hand along its seating where a fabric patch covered with rubber solution secured the valves to the gas bag. The seal was intact and had no ruptures. Then he placed his ear close to the seal and listened for escaping hydrogen. He heard no hissing. To test for smaller leaks, Erwin held up a bit of tissue paper. He saw no fluttering. Then, casting his light around the gas bags, he noticed holes. He climbed to the top, more holes. He returned to the walkway and continued his inspection, discovering holes in gas bags five, nine, ten, eleven, twelve, thirteen, and fourteen. He found holes in seven of R101's fifteen gas bags. They were tiny, a mere three-eighths of an inch in diameter, yet they worried him. Erwin was troubled by the hole's origin. The quest for increased lift by letting out the wire netting, restraining the gas bags, had defeated itself. The newly enlarged gas bags chafed on the sharp edges of the framework bolts, which sliced the bags in many places, and, Erwin noticed, indented them in thousands of locations. If the rattling of the gas bags caused this much damage on a short flight, then the motion of the gas bags could cripple the ship on the long flight to India. Although alarmed by the holes, Erwin was sure they were not the cause of R101's dives as it flew to and from the Hinden airfield. Even allowing, he reported to his superiors at the works, for the numerous holes which are now found in the gas bags where they have rubbed in the framework, the loss of gas would not have accounted for the heaviness of the ship during flights. Erwin suspected that the automatic gas valves were leaking hydrogen, perhaps too much. He had three concerns. First, the valves were easily triggered intentionally to avoid gas bags bursting on R101's trip to India. Unroot, the airship might encounter a tropical thunderstorm where turbulent air could force it high into the sky and burst a gas bag unless rapidly vented. So, the valves were calibrated to expel large quantities of hydrogen. Second, in shed tests the gas valves leaked when tilted to five degrees. And third, on the last Hinden flight, a rigor heard chattering of the valve on gas bag eight. So, Erwin hypothesized that in the turbulence of the flights to Hinden, the gas bag surged and the ultra sensitive valves opened. Although he suspected the gas valves were the chief culprit in R101's instability, he knew that the holes created by the chafing on the framework posed an equally grave danger. He ordered his crew to do a thorough inspection of each gas bag, followed by padding of the framework's longitudinal, radial struts and reefing booms. As crew members glued patches over the holes in the gas bags and padded the framework as a consequence of Erwin's findings, Mr. Fred Brink McWade inspected their work. The Royal Airship Works had, like every large British aircraft manufacturer, a resident inspector assigned by the government's aeronautical inspection director at AID. An aviation inspector was regarded by the average person, wrote Flight Magazine, as a sort of backstair detective who disguised in a bowler hat and a false beard and armed with a macrometer, lurks behind machinery and airplane factories. In truth, the magazine's writer clarified, the inspector is an extremely human and hardworking civil servant. Indeed, McWade coordinated his inspection with the Works' drawing office, which issued all orders for construction and maintenance. An office so important, the McWade joked that if it was necessary to move a table from here to there, I should get the drawing office instructions. The office drew up orders for construction or for changes. McWade reviewed them and issued a small white chit if he approved. Then the work was done. He repeated the inspection and issued a pink chit to certify he approved of the final result. Despite McWade's intimate role in the daily routine of creating and maintaining R-101, AID regulations required that he form opinions independently of the work staff about the ship's deficiencies and the efficacy of any corrections. His regular reviews for the ship deepened the brain trust creating R-101 because he could draw on nearly 35 years of experience with lighter-than-air craft. He had begun with balloons when most of the work staff were still in diapers, then headed the construction of Nellie Secundus, Britain's first military airship. He spent 27 years building and inspecting airships and knew the joys and difficulties of building them and the terrors of flying them. He rode in Nellie Secundus when, on its second flight, the ship plunged to the ground and shattered its metal framework. His opinions were paramount because he recommended monthly whether the director of civil aviation should issue a permit to fly. This legal document allowed experimental aircraft like R-101 to be flown without having been certified as airworthy. It restricted R-101's test flights to know further than 250 miles from the Royal Airship Works, forbade it from carrying passengers for higher or reward, and noted it may be withdrawn at any time. The current permit expired in less than a month at the end of July 1930. McQuaid now had to recommend a new one, but the holes in the gas bags concerned him. Only a few weeks before, McQuaid reflected, the bags were reconditioned, removed from the ship, examined, repaired, reinstalled, and reinflated. Yet now the framework was punching holes in the bags. To investigate the conditions of the bags himself, McQuaid climbed into the airship and repeated Irwin's inspection. At nearly sixty, climbing on the gas bags was harder for him than for Irwin, who was twenty-two years younger and a former Olympic athlete. Once in the gas bags, McQuaid aimed his lamp onto the padded framework. He leaned forward and rubbed the padding. To his surprise it easily moved. How he wondered could this padding protect the gas bags if the ship flew in rough weather? He parted the padding and studied the framework. He ran his fingers along his sharp nut and the end of the bolt. He realized that there could be thousands of puncture points in the gas bags. The padding worried him for another reason. How could he or anyone else tell whether the metal framework underneath was sound? It could well corrode and no one would know. McQuaid's observations compelled him to alert his superiors. Though he always addressed his report to his immediate superior, this time anxious that it should be read by the highest ranking official, McQuaid blazoned for the attention of DAI, AID, and red letters across the top. The DAI, the director of aeronautical inspection, ran the directorate and was two ranks above McQuaid. He headed his report, confidential, HMA R101, then added a subheading, airworthiness of the above ship. In crisp prose he detailed the problems. Padding he reported is, in my opinion, very unsatisfactory because the bags move when the ship is in flight and the padding becomes loose and the projection, i.e. the bolts, complained of, is again exposed. He alerted his superiors to the possible lethal consequences of the padding. The fabric will become damp and in many cases wet when the ship is in flight. Therefore there will be alternate processes of wetting and drying of the fabric which must be detrimental to the metal underneath. He closed with a stunning conclusion. Until this matter is seriously taken in hand and remedied, I cannot recommend to you the extension of the present permit to fly or the issue of any further permits or certificates. In McQuaid's opinion, the remedy required a change of construction in the gas bag wiring and framework, a rethinking of two miles of girders, eight miles of tubing, 15 miles of rods, and 11 miles of cables that composed R101's framework. As an experienced airship builder, he knew that this would be a large undertaking but he saw no other course. Never in his years of experience with airships had a systematic structural defect been fixed by padding the framework. So in early July 1930, R101 floated in its shed, banned from flying. The work staff prepared to execute the second stage of the refit, the miracle as Atherston described it, to increase R101's lift in time for a demonstration flight to India three months away but years behind schedule.