COMET Chapter Five - A Stunning Blow

 

I invite you to watch as the sleek midnight blue and white aircraft designated “Yoke Yoke” (above) glides in for a landing on  runway 15/33. The four de Havilland Ghost turbojet engines cradled close inboard within the wings are throttled back to idle, as 38 year old South African Airways Captain William Mostert gently sets the 100,000 pounds of aluminum alloy, wires, rubber tubing, kerosene ambitions and 21 souls onto the asphalt. It is 4:36 pm on the cool evening of Wednesday, 7 April, 1954. As the twin four-wheeled bogies of “Yoke Yoke”s landing gear absorb the impact, the crew and passengers of Flight 201 have less than 25 hours and 30 minutes to live. (https://www.youtube.com/watch?time_continue=320&v=vkMHJmkx6E8&feature=emb_logo)

There were warning signs before the de Havilland Comet Yoke Yoke landed at Rome's Ciampino Airport,  completing the first leg of a flight ultimately headed for Johannesburg, South Africa. And although the Comet bore the colors and logo of the British Overseas Aircraft Corporation, the flight and crew were a South African Airways operation. 

The strain of the shut down after the crash of Yoke Peter, and the 60 recommended repairs, were forcing de Havilland to miss production commitments. There was no Comet 1 available for this scheduled SAA flight. And since the Comets leased to South Africa, Air Canada and Air France produced needed foreign currency, de Havilland and the government convinced BOAC to charter Yoke Yoke to SAA for the flight. It was a jury rigged, temporary fix to the Comet's problems.

But the problems ran deeper. SAA flight 201 was supposed to be on the ground in Rome about about an hour -just long enough to refuel. However no matter how much fuel they put in Yoke Yoke's center fuel tank, the gauge refused to move. The flight was delayed while the engineers searched for the source of the problem. 

After draining the central tank, by elimination, it was assumed the co-axial cable running from the wing tank to the gauge was faulty. Which is when it was discovered that neither SAA nor BOAC Ciampino had a replacement cable in stock. A new cable would have to flown out from London, requiring Yoke Yoke to remain overnight in Rome.

That was mildly embarrassing, especially since de Havilland and BOAC were proudly declaring their primary advantage over piston engines was that the turbines of a jet required far less maintenance. In fact the entire industry was already moving from “maintaining” an aircraft at each stop, toward merely providing “service” - meaning only major transportation hubs would keep a collection of parts and mechanics. And the fuel indicator cable had not been considered to be essential. Oh, well. Part of the learning curve. So the passengers were put up in a hotel, and while waiting for the replacement cable it was decided to drain and inspect all the fuel tanks, just in case some thing else was the real problem.

And that was when they found, rolling around in the empty left wing tank (above) of Comet Yoke-Yoke,  22 quarter inch bolts. A panicked phone call to London eventually produced an answer to the mystery of what they were doing there. Nine days earlier, 52 bolts had been removed during a routine check of the tank. For some reason only 30 of those had been restored before closing the tank. People were going to be fired over that mistake. But it got worse. While double checking all of the bolts, it was discovered that even the remaining 30 had not been fully tightened. For nine days the port wing tank had flown with less than half the structural support it was designed to have. The only thing which saved Yoke Yoke on all the flights during those nine days had been the redundancy de Havilland designed into the Comet. It had been a damn close call.

So, 25 hours late, on Thursday, 8 April, 1954, Comet Yoke Yoke left Ciampino airport bound for Heliopolis Airport, just east of Cairo, with a crew of 7 and 14 passengers. Five minutes after take off, at 5:37pm Central European Time, Yoke Yoke reported passing over the Ostia coastal beacon, 30 miles west southwest of Rome, at 7,000 feet. 

At 5:49pm, the Comet reported passing over the island of Ponza, 75 air miles from Rome, and climbing through 11,600 feet. Twenty-five minutes after take off, at 5:57pm, Yoke Yoke reported they were abeam with Naples, having covered 118 miles by air. They were now approaching their cruising altitude of 35,000 feet. At 6:07pm CET, Yoke Yoke contacted Heliopolis and reported their Estimated Time of Arrival would be 9:02pm. Some time after that broadcast, Comet Yoke Yoke simply disappeared. No one saw or heard an explosion. No one saw the debris fall from the sky. The plane simply vanished.

Such a loss was not uncommon at the time, even with a reliable workhorse like the Douglas Commercial -4, of which over 1,200 were built between 1943 and 1949.  On Thursday, 26 January, 1950 a U.S. military DC-4  (above) disappeared over the Yukon Territory, Canada, with 44 souls aboard. Despite a 2 month long search involving 85 Canadian and American aircraft and 7,000 personnel, no wreckage has ever been found, and no cause ever determined. 

On the morning of 23 June 1950, Northwest Airways flight 2501, with 58 souls on board, disappeared over Lake Michigan. After a six week investigation, the cause was listed as “unknown”. 

On 21 July, 1951 a Canadian Pacific Airlines DC-4  (above)  carrying 27 souls,  disappeared south of Anchorage, Alaska. No wreckage has ever been found. The cause is listed as “...not determined." It was not that pilots and engineers lacked curiosity, but rather that no one had yet designed a recording device which could survive a crash violent enough to kill passengers and crew. But it was coming.

Independently in 1953 both David Ronald de Mey Warren with Defense Science and Technology Organization, in Melbourne, Australian,...

...and Professor James Jay "Crash" Ryan, at the University of Minnesota, U.S. - who also invented the automobile retractable seat belt - ...

...designed wire recording systems which would note engine temperatures, fuel flow, aircraft velocity, altitude, control surfaces positions, and rate of descent, and could survive a crash. From the beginning it was decided to put these “black boxes”, aka Flight Data Recorders,  in the tail, since, as one designer put it, “I never saw an airplane back into a mountain.”

Ryan got a U.S. Patent in 1953, but Warren's work got quicker attention from the industry, specifically in 1958 from Sir Robert Hardingham, then Secretary of the British Air Registration Board. Hardingham was interested, in large part, because of the Comet crashes.

Then, on 4 June 1967 a British Midland DC-4 (above), with 84 people on board, crashed in a suburb of Manchester, England. The captain was one of the 12 survivors, but he had no memory of the events just preceding the crash. 

Luckily, however, the now required “black box” did remember. All DC-4's had 8 fuel tanks and a complicated plumbing systems to keep the aircraft balanced during flight. This crash – and perhaps earlier ones - had been caused because the cockpit fuel line controls were complicated and difficult to operate. In effect, the crew had chosen an almost empty fuel tank for the 2 right side engines, and during landing approach they both abruptly lost fuel and power. The aircraft flipped over and spun into the ground, 

However the box also showed the desperate pilot retained just enough control to prevent the plane from slamming into homes. No one on the ground was killed.

But on Friday, 9 April, 1954, the search planes could find nothing left from Comet Yoke Yoke except an oil slick and five bodies floating in the Mediterranean. By the time ships arrived, even these were gone. 

The next day the New York Times would report, “ “Britain today weighed the cost of a stunning blow to her proudest pioneer industry – jet civil aviation – as the crash of another Comet airliner was confirmed. Twenty-one persons, including three Americans, were believed to have died when the plane was lost in the Mediterranean...Tonight the Minister of Transport, A. T. Lennox-Boyd withdrew from all Comets the certificate of airworthiness... Sir Miles Thomas, chairman of the airline, said the new crash was 'a very great tragedy and a major setback for British civil aviation.'”:

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COMET - Chapter Four - Denial and Anger

 

I hope the grieving families of the 15 dead recovered from the ocean found some comfort in knowing that while awaiting burial their loved ones rested in peace in the dark little chapel of the fortress Chiesa di San Giacomo Maggiore, treated with reverence and honor. Except they were not left at peace. They could not be for the sake of the living. Each evening a handful of bodies were removed and carried to the hospital in Portoferrai on Elba's north shore.

Awaiting them there, scalpel in hand, was Antonio Fornari, the Professor of Pathology at Pisa University. It was Professor Fornari's job to learn from the dead, to discover what exactly had killed those privileged enough to have flown on the wonder of the modern world, the de Havilland Comet.

What Professor Fornari learned from the autopsies was that none of the bodies recovered from the sea had drown. None had either water nor smoke in their lungs. None had suffered shrapnel wounds. All 15 had ruptured lungs. Most also had suffered skull fractures, concurrent with their deaths. Professor Fornari was certain the combination of these two injuries were the primary cause of death in all cases. And he suspected the cause was an explosive decompression. But aviation medicine was beyond his training.

However, he did observe that all the victims had also suffered broken arms and legs. One body even had a leg entirely ripped off. But those injuries had been suffered postmortem. More, all of the victims had their clothing disturbed. Many were almost naked. One had only lost a shoe. And although none showed any signs of having been exposed to a fire, most bore marks similar to scalding on their backs. Three also had scalding marks on their face. One corpse had scalding marks on their chest and abdomen as well. In the end the Professor was unclear what this all meant.  

But after each autopsy, the body was made as presentable as possible and placed in a coffin before being returned to the chapel, for eventual delivery by British Overseas Airways Corporation and then to their families.

The next question was how to get the 70 to 80% of the Comet Yoke Peter, presently sitting on a barge in Porto Azzurro back to the Royal Aircraft Establishment at Farborough - about 40 miles west southwest of London. By ship it might take months. 

However there was one aircraft in 1954 which was capable of carrying the wreckage from Italy directly to England; the American built Fairchild C-119 (above),  popularly known as the “Flying Box Car”.  It's distinctive twin boom tail allowed easy loading and off loading from its 10 foot by 8 foot cargo hold. And it could carry a ton and a half of weight. The United States Air Force readily agreed to provide a “Box Car” for the transport flights back to England.

In the meantime, Arnold Hall, Director of the Royal Aircraft Establishment, wanted to confirm Professor Fornari's suspicion about the rapid decompression. A model of the Comet's fuselage was constructed at Farnborough. Dummies sat in for the passengers. 

Then, as film camera's rolled, the fuselage was pumped full of air until the container burst. In the explosive decompression the dummies were thrown forward into the back of the seat in front of them, or slammed into the ceiling. This confirmed Professor Fornari 's findings.

As the bits and pieces of Yoke Peter arrived in Farnborough (above), some new discoveries were made. 

Shreds of the cabin carpet were found tangled in the interior of Yoke Peter's tail (above).  A rear fuselage panel bore the distinct imprint of a coin from some passenger's pocket. And paint smears on the rear fuselage had been left by the passenger seats. These were all more evidence of an explosive decompression. But what had caused it? A bomb? Or had one of the Ghost engines exploded, ripping apart the pressurized cabin? 

Clearly the fuselage had come apart in mid-air, but where had the destruction begun? Workers at Farnborough began to reassembled the skin of Yoke Peter on a wire frame. It was a technique which would be used on many future aircraft losses.

Those most closely associated with the Comet were stunned by the accidents, and the groundings – or at least they later claimed to be. With their future careers clearly tied to the success of the Comet, BOAC Captain, R. Clifford “Cliff” Alabaster would later admit, “Initially, we didn’t think it could be mechanical breakup. We had every confidence in the airplane.” And Captain Ernest “Rod” Rodley agreed. “It was a perfect airplane as far as we were concerned. We were absolutely puzzled by the problems.” And a generation of pilots matured in the shadow of RAF Bomber Command, who endured a 46% death rate from 1939 through 1945, would reflexively follow orders even when common sense said to do so was suicide.

The Ministry of Transport and Civil Aviation, Mr A. T. Lennox-Boyd (above, left), had so far resisted pulling the Comet's Air worthiness certificate, in part because de Havilland and BOAC as well as Air France and the South African Air Service ordered all Comets returned to London without passengers, and at reduced speeds and altitudes.  But Lennox-Boyd did seek the opinion of the Air Registration Board. This group had been formed in 1937, and was made up of 4 representatives of the airlines 4 representatives of insurance firms, one professional pilot and a representative of the general public, the last two appointed by the Secretary of State. 

The pilot on the board was Peter Duffrey (above),  and as he recalled, “We had a series of meetings at Heathrow. They were quite sure they'd covered what was going on.”

The board considered the possibility of sabotage, and recommended increasing security around the jets. In case one of the Ghost engine's turbines had exploded, they proposed putting a sheet of steel between it and the pressurized cabin. They recommended installing weather radar in future Comets, so thunderstorms could be avoided. 

They recommended modifications to the wings, to increase lift at low speeds. They even considered the possibility of a failure of the pressurized cabin, but the extensive mathematical calculations by the de Havilland engineers, and the generous margins for safety used, convinced the board to reject this as a possibility. In all, 60 modifications were recommended.

The financial pressures after 10 weeks were tremendous. Both de Havilland and BOAC were hemorrhaging money. Salaries of pilots, mechanics, ground crews and support staff continued, while payments on loans taken out to build the Comet continued to pile up.  And British technical capabilities were now being openly questioned around the world. Because of the bad publicity, future sales were slipping away. 

As the editor of one British aviation magazine showed, it was a situation ripe for justification. “The positive cause of the accident may never be found," the author reasoned, "though every effort will be made to do so. The results of the public inquiry will undoubtedly be interesting, but they are not likely to be conclusive...To this extent one agrees with the more vigorous shouts from the Press. Now that we have done everything that the technicians consider necessary to forestall trouble in the future – Let us get the Comet flying again!”

Pilot Peter Duffrey (above) explained, “I voted against, because I felt the modifications had not adequately discovered the reason for the explosion.”  It did not matter. By a single vote the board recommend to release the Comets. 

So, on 5 March, 1954 - 54 days after the sudden and violent deaths of the passengers and crew of Yoke Peter - Air Chief Marshal Sir Frederick Bowhill (above), writing as if the board vote had been unanimous, told his Minster that while, “.... no cause has yet been found that would satisfactorily account for the Elba disaster...everything humanly possible has been done to ensure that the desired standard of safety shall be maintained. This being so. the Board....recommends that Comet aircraft should return to normal operational use...”  And so did he.

All recommended modifications were made as quickly as possible. Perhaps too quickly. And three weeks later, on 23 March 1954, the first Comet, with a full load of enthusiastic paying passengers, lifted off from London.  Sir Miles Thomas, Chairman of the British Overseas Airways Corporation, explained, "We obviously wouldn't be flying the Comet with passengers if we weren't satisfied conditions were suitable." 

And two weeks later, on Thursday, 8 April, 1954, Comet Yoke Yoke, carrying 14 passengers and 7 crew members, disappeared 25 minutes after taking off from Rome.  Decades later, Peter Duffrey would admit, “I still do not forgive those who restarted the services...”  The board members had been gambling with the lives of the crew and passengers. And as Duffrey noted, "I was one of the chits" they were gambling with.

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COMET - Chapter Three - Spirits Of The Dead

 

I ask you to witness the sad little fleet dock in the port of Azzuro (above), on Elba's eastern shore. It is some 7 hours since Yoke Peter fell into the cold Tyrrhenian Sea, and dusk is settling over the strait of Piombino - 10 January, 1954.  From the trawler Francesco Guiseppe they carry the pale corpse of a 10 or 11 year old boy, strapped atop a wooden plank and covered by a fresh white sheet. The somber fishermen then carry off the body Jean Evelyn Clark, a 29 year old stewardess. 

She is followed by a procession of 12 more shroud draped bodies up the dirt road and into the stone fortress of Chiesa di San Giacomo Maggiore (above). 

In the fort's small, austere, baroque chapel the burdens are laid before the altar. 

Candles are lighted and prayers are intoned. And if the spirits of the dead should have awakened, they must have been surprised to find themselves in such a dark sanctuary, such a long way from the cold thin air so close to heaven where they died.

 Because de Havilland had built Britain's second jet fighter, the single engine Vampire (which went into service in April of 1945), they believed they were uniquely qualified to build the Trans-Atlantic passenger jets envisioned by the Brabazon Committee. However these would require a range of over 3,000 miles. And the second generation Ghost engines burned 3 – 4 times more fuel at 10,000 feet than conventional internal combustion engines, putting New York well beyond their range. So the cautious de Havilland company decided to approach trans-Atlantic flights in stages.

The Comet 1 would establish profitable routes tying the the British empire together, with flights between London and Singapore or South Africa. 

These largely overland routes would allow refueling stops every thousand miles or so, over well established paths, using already established ground facilities. Once the Comet was proven and the three times more powerful Rolls-Royce Avon engines had completed their testing, de Havilland would build the larger transcontinental Comet 2, and then the even larger Comet 3. So from the beginning the Comet 1 and it's Ghost engines were envisioned as test beds.

Throughout 1947 and 1948 de Havilland subjected the Comet fuselage and its over-sized square windows (above)  to twice anticipated pressures, through 16,000 cycles from sea level to 36,000 feet and back, simulating over 40,000 service hours. 

Since each rivet holding the Comet's aluminum skin required a hole be punched, the decision was made to use the adhesive “Redux”, proven in combat on the plywood fighter/bomber, the Mosquito. It would be used on the Comet primarily “...to affix stiffening...to wing and fuselage panels, the resulting panel being both stronger and lighter than a riveted structure.” After all this was tested and proven, the design was finalized and built.

Not until after three years of testing did the Comet fly. The test pilot John Cunningham described this marvel of modern technology as “Very promising. Very quick.” British Overseas Aircraft Company bought 8 Comet 1's. 

Air France  (above) bought a pair,  South African Airways bought another two, as did Canadian Pacific Airways.  And the American giant, Pan American World Airways, signed up to buy three of the Comet 3s, with an option to buy 7 more the following year. With each Comet sold abroad representing over half a million pounds in badly needed foreign currency, and with “eight BOAC Comets leaving London each week: three to Johannesburg, two to Tokyo, two to Singapore and one to Colombo”, by the summer of 1953 it seemed the Comet was indeed a revolution in passenger travel.

However there were some annoying problems. The vacuum tubes in the navigation system tended to overheat. The cockpit's windows would occasionally fog over. And the seals on the hydraulic control system, which powered the flaps and tail rudder, were faulty on the first four Comets. Crews solved this problem by carry extra cans of fluid, and would top off the system whenever they spotted fluid on the tarmac.

And then there those under powered Ghost engines. In late October 1952 a BOAC Comet taking off from Rome, Yoke Zebra, failed to reach V-2, the speed at which pilots would lift the nose to become airborne. Unable to lift up or stop, Yoke Zebra overran the runway and broke the landing gear (above).  Pilot Peter Duffrey, who had flown the Comet into Rome,  found Yoke Zebra, “... just sitting there hissing – it (had) ripped the belly tank out and there was fuel everywhere.” Luckily there was no fire and no loss of life.  

But Duffrey diagnosed the problem immediately. The pilot had raised the nose too high after liftoff, and stalled the aircraft. But the pilot was not helped by the hydraulic system. Duffrey noted, “...the lack of feedback on the controls...allowed you to pull-back as much as you wanted.” That made it easy to stall the aircraft.

That mistake was repeated on 3 March 1953 during the unladen delivery flight of a Canadian Pacific Comet, this time just after lifting off from Calcutta. This time all six crew members and the six passengers on board were killed. A week later a Comet test flight out of Karachi, Pakistan, stalled after lift off and slammed into a stone bridge, killing 11 technicians and crew. This crash cost de Havilland the second Comet the Canadians had ordered but not yet taken delivery on. 

Then, in June, it happened again, this time in Dakar, Senegal. Said Duffrey, “As pilots we were becoming very concerned.” In response, new take-off instructions were issued to pilots, and in all future Comets modifications would be made to the wings, and all future Comets would be fitted with weather radars.

Then had come the Yoke Victor tragedy over Jagalgori, India (above). It had been blamed on the weather, but pilot error had not been ruled out. Nor had sabotage. There were a lot of people in Asia and Africa who had an grudge with the British Empire. And a lot of older pilots were suspicious about those new hydraulic controls. And now there was this new disaster over the Tyrryenian Sea. The negative publicity was certain to kill desperately needed sales. 

With 24 hours of prodding from Arnold Alexander Hall (above), Director of the Royal Aircraft Establishment, both de Havilland and BOAC agreed to temporarily ground all Comets. Hall then opened a comprehensive investigation, which began by looking for nefarious causes and actors.

Admiral Louis Francis Mountbatten (above), 1^st Earl of Burma and Commander of the British Mediterranean Fleet, was ordered to recover as much of Yoke Peter as possible. 

However the Comet tragedy coincided with a series of devastating 7.0 and above earthquakes in Greece, which followed the ruinous Greek Civil War. Mountbatten was also the NATO commander in the Med and in that role, the fragile state of Greek politics and economics made relief efforts the priority over Comet recovery. 

Although he had to continuously shift his resources, Mountbatten still managed to maintain at least one frigate with SONAR and at least one British minesweeper on station in a grid pattern search for debris of Yoke Peter, directing 5 local fishing trawlers dragging the bottom.

It was not easy. One engineer, viewing the search through a primitive video system, described the ocean bottom as looking “as though someone had upended a waste-paper basket”. Still, by 15 March – 65 days after the crash – the Royal Navy had recovered a large section of the front of the fuselage and part of the wings. Four days later they had recovered all 4 Ghost engines. If anyone had noticed the similarity in the way Yoke Peter had broken apart in January and the the pattern Yoke Victor had fallen from the sky 7 months earlier, they were not talking in public.

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