In-air break-ups of Commercial Airliners

The Wright Flyer. Source: Library of Congress

In episode 10 of Plane Crash diaries we investigated in-air breakups of aeroplanes – caused by poor flying, poor design, or poor maintenance and bad weather. In some cases all four of these together.

However as with all things aviation, every accident leads to an equal and opposite reaction .. to misquote the great Sir Isaac Newton.

That reaction luckily for us, is called Aviation safety standards. The terrible truth is that people die and then safety improves.

So let’s start with the 32 year-old Charles Rolls. He was one half of the great Rolls-Royce engine company but his end was rather unfortunate.

He was killed when the tail of his Wright Flyer aircraft fell off in 1910 in Bournemouth and thus was unceremoniously ushered into aviation history as the first to die in a British air accident. And he was one of the first Englishman to die in what became known as in-air break up. The Wright Flyer was a copy of the original Wright Brothers plane that flew at Kittyhawk in 1903.

That didn’t stop Rolls-Royce from turning into developing the world’s top turbine engines but it put paid to the Wright Flyer which was largely out of date anyway by then and Rolls’ demise proved it was not really built to last.

Probably the most famous of all in-air break ups involved the notorious de Havilland Comet. It took three catastrophic failures all within a year before the airliner was grounded.

Launched by BOAC in 1952, the Comet was the world’s first jet airliner and was an attractive plane too. Aviation buffs swooned over its swept back look, the modern jet liner was born and it could fly right across the Atlantic without a stop.

However, it had a serious flaw. The windows and doors.

At that time the way in which aircraft fuselage expanded and contracted due to the huge pressure differences was not well known and the engineers built a defect into the Comet.

They had rectangular windows. We now know all plane windows are rounded in shape, and that’s for a reason and you can thank the Comet for the safer windows we enjoy on board our commercial flights.  

In 1953 and 1954, three Comets broke up soon after take-off killing everyone on board. Two of these break-ups took place over the Mediterranean while the plane was climbing to its cruising altitude and a third crashed in a thunder storm on a flight from Calcutta to Delhi in India.

In January and April 1953 the two that crashed in the Med took off from the same airport – Rome’s Ciampino. At first there were thoughts about sabotage, perhaps explosives.

De Havilland Comet. Beautiful but lethal. Source: Wikipedia.

However after the Comet crashed in India, the plane was grounded. An extensive programme that followed has since been copied in many plane crash investigations. The probe was led by Sir Arnold Hall who was director of the Royal Aircraft Establishment at Farnborough. Engineers rebuilt the recovered wrecks on the ground, and then subjected the hull of a new jet to pressurisation tests in a massive water tank.

Rebuilding wrecks on the ground is now standard practice.

Eventually, Sir Arnie and his team of boffins discovered what had been going wrong. Cracks developed in the fuselage around the doors and window apertures as the plane was subjected to pressure changes mimicking take offs and landings.

The rivets around the doors and windows could not take the stretching forces and all three plane’s had literally blown apart at the seams in mid-air. Doors that were rounded were fitted – similar to what we now see on all aircraft, while the windows were also changed.

The Comet was redesigned and then renamed the Nimrod which continued flying more than sixty years after the maiden Comet flight in 1949.  Used mainly by the military, the Nimrod continued in various forms until 2011 deployed as an advanced and dedicated airborne early warning platform and maritime patrol aeroplane.

Across the Atlantic, aviation engineers in the United States were watching the terrible Comet crashes with a great deal of interest.

Britain may have launched the first commercial jet, but America was going to make air travel its own.  Boeing and Douglas were the two manufactures to benefit from the new safety rule of building with round doors and windows.

Engineers in the United States  took note of the new designs and were able to incorporate these into the hugely successful jetliners made by Boeing and Douglas that were to dominate not just transatlantic but global long-distance services.

As some have said, it was the passengers of the three Comets who paid for Boeing and Douglas’ research – with their lives.

We will leap forward to the 80s for our next example.

One of the most incredible in-air failures ended with almost everyone surviving. In April 1988, part of the fuselage of an Aloha 737 flying from Hilo to Honolulu shredded at 24,000ft.

Route of Aloha Airlines flight 243 which was flying from Hilo to Honolulu. Source: NASA.

A flight attendant was swept overboard – everyone else survived.  Imagine sitting in the open air with nothing between them and the ocean except for a safety belt.

The Boeing 737 had reportedly experienced more than 89 000 re-pressurisation changes.

This led directly to the Federal Aviation Authority setting up the National Aging Aircraft Research Programme. Testing defects in design, the effect of corrosion, resonances in different metals and so on, the Aircraft Structural Test Evaluation and Research facility was launched.

Predicting where and after how long structures would fail due normally to repetition, helped increase safety in aviation.

That may be so, but it took a 1991 accident to kick start a proper global culture of aviation safety.

The mid-air break up of the Continental Express Flight 2574 – an Embraer 120 Brasilia, was a scheduled domestic passenger airline flight operated by Britt Airways from Laredo International Airport in Laredo, Texas, to Houston Intercontinental Airport  or IAH in Houston, Texas.

With terrible timing for later events, on September 11, 1991, the Embraer, crashed, killing all 14 people on board. The aircraft wreckage hit an area near Eagle Lake, Texas which is located approximately 65 miles west-southwest of its destination of Houston.  

Flight 2574 wreckage map. Source: NTSB report.

Initial reports suggested a bomb was the cause of the plane coming apart, but the National Transportation Safety Board found the real cause were missing screws on the horizontal stabilizer.

It’s always horrible to consider that the crew consisting of Captain 29-year-old Brad Partridge and first officer 43-year-old Clint Rodosovich together with 33-year old flight attendant, Nancy Reed did nothing wrong.

Both Partridge and Rodosovich were experienced pilots with 4,243 flight hours and 11,543 flight hours (including 2,468 hours and 1,066 hours on the EMB 120 Brasilia).

The EMB 120 took off at just before ten past nine in the morning of  the 11 September and were cleared to cruise at 25 000 feet.

At a few minutes to ten after reaching the cruising altitude, Houston Air Route Traffic Control Centre reassigned 24 000 feet. Then as it continued descending for Houston Intercontinental Airport descending through 11 500 feet at around 260 knots, the leading edge of the left horizontal stabilizer separated from the airframe.

The plane pitched down dramatically, rolling around its axis and the left wing folded like cardboard. The fuel escaped and ignited. Mercifully it is believed all passengers and the pilots lost consciousness in the massive G-forces that were produced in the spin.

The crippled craft fell in southeast Texas exploding on impact. The wreckage was spread over almost four square miles – some even making it to the Colorado River many miles away.

IT was the maintenance crew who were blamed. The previous evening they were working on the stabilisers but there had been a shift change and the screws that were removed from the horizontal stabilizer had not been replaced.

This led to major changes in safety inspections before during and after maintenance.

The FAA conducted a National Aviation Safety Inspection Program (or NASIP) of Continental Express’ maintenance program. Because the failure to inspect the parts after the shift changeover was recorded, NASIP processes were then regarded as deficient.

The big change linked to the in-air break up of this plane was the dramatic turning point in Safety Culture in the United States. That had a knock on effect worldwide.

Safety culture became the watchword, then in April 2000 the Wendell H. Ford Aviation Investment and Reform Act for the 21st Century, or AIR 21 was launched.

The most important part of the bill was the inclusion of the “Aircraft Safety Act of 1999,” which proposed to help stop the practice of manufacturing, distributing, and installing fraudulent aircraft parts. I’ll feature this terrible scourge in a future podcast too – how grey parts have caused many accidents.

A break-up of a plane over Peru deserves special mention at this point. As you’ll hear in this series, there are many examples of a single person surviving a plane crash. And this is one of them.

Today we hear about the extraordinary story of Juliane Koepcke. She was 17 years old and sitting in the window seat next to her mother on board a Lansa Aircraft flight 508 from Lima in Peru to Pucallpa in the middle of the Amazon Rain Forest.  

The final destination was a town further on called Iquitos.

It was Christmas eve 1971 and Juliane had just written an exam. More about that in a moment.

Lansa Flight 508 was a Lockheed L-188A Electra turboprop, registered OB-R-941, operated by Lineas Aéreas Nacionales Sociedad Anonima  or LANSA for short.

The plane took off from Lima then  flew into a thunderstorm just over the Andes. The storm was accompanied by turbulence. It’s thought that a bolt of lightning then struck one of the fuel tanks and it exploded, tearing off the right wing.

The Lockheed went into a spin and disintegrated.

All 91 of the 92 passengers and crew were killed, except for one – Juliane Koepcke.

Juliane Koepcke in 2019. Source: Munich University.

The German teenager was thrown out of the plane still strapped to her seat. As film maker Werner Herzog said, she didn’t leave the plane, the plane left her.

Juliane later re-countered how she remembered falling head first with the seatbelt digging into her stomach and a canopy of trees spiralling towards her.

Then she lost consciousness but woke up the next morning on the floor of the rainforest.

She had dropped two miles through the air and had a broken collarbone, a gash on her leg, a small cut on her arm and a mild concussion. But she could walk.

Juliane had a much bigger problem. She was stuck in the middle of the rainforest with only a small bag of sweets. Worse, her glasses had been lost and she couldn’t tell the difference between a leaf and a wriggling snake.

But she knew quite a bit about jungles – even as a 17 year-old. You see She was the only child of biologist Hans-Wilhelm Koepcke and ornithologist Maria Koepcke. When Juliane was fourteen, her parents left Lima to establish a research station in the Amazon rainforest.

She became a “jungle child” and learned survival techniques. But German educational authorities disapproved and ordered the family to send her back to Deutsche Schule Lima Alexander von Humboldt to take her examinations which she did a few days before the crash.

IT was because of their demand she write exams in Lima that the child of the jungle ended up falling into the jungle.

Of course she was surrounded by a long list of animals, plants and insects that were deadly. Somehow she survived for ten days and was eventually  found by forest workers on January 3rd 1972. She had no boots, no machete, no glasses.

Really an incredible story.

Koepcke became an international sensation. The young German then decided it was all too much and took a decision to disappear by 1973.

Eventually she remerged in 2011 when her memoir of the crash called When I Fell from the Sky,  was published. Juliane is still alive and is a mammologist who specialises in Bats and lives – I hope – a quiet life as librarian at the Bavarian State collection of Zoology in Munich.

While the lightning strike which is still known as the deadliest in aviation history, it’s also an example of poor decisions by the air crew. Instead of diverting because of thunder storms the LANSA captain decided to continue because of pressure to meet the holiday schedule.

Get there-it is its called in aviation. Get there even when its wiser to wait.

Peruvian investigators cited “Intentional flight into hazardous weather conditions” as a cause of the crash.

There’s another I have to mention and it involved something known as Clean Air Turbulence which led to an in-air breakup of a commercial airliner.  

In the case of BOAC flight 911 callsign Speedbird 911, clean air turbulence produced

an estimated 7.5Gs that caused the Boeing to disintegrate over Mount Fuji in Japan on 5th March 1966. 

Clean Air turbulence will be covered in a future podcast, but needless to say there’s no warning.

All 113 passengers and 11 crew perished.

The Boeing was still climbing out of Tokyo and had reached 16 000 feet when it hit the massive clear air turbulence flying at 370 knots.

Analysis of wreckage allowed the accident investigators to determine that the vertical stabiliser attachment to the fuselage failed first. Then the port side horizontal stabiliser failed as the plane spun to the left.

BOAC Flight 911 intended route. It crashed shortly after take-off. Source: ASN Aircraft Accident Database.

A short time later, the ventral fin and all four engine pylons failed followed by the remainder of the empennage.  

The aircraft then entered a flat spin, with the forward fuselage section and the outer starboard wing breaking off shortly before impact with the ground.

An 8 mm film exposed by one of the passengers was recovered from the wreckage. It showed pictures of the Tanzawa Mountains and Lake Yamanaka, followed by two empty frames and then apparently images of the aircraft’s interior, before ending abruptly.

Tests suggested that the two empty frames may have been the result of structural loads of up to 7.5 g momentarily jamming the camera’s feeding mechanism.

Investigators did find stress cracks in parts of the tail assembly. But even without the cracks, the plane would have broken apart. What really put paid to the Boeing was the wind and Mount Fuji.  High winds flowing over the 12 388 foot peak meant tricky air currents in the vicinity.

I’ve hit winds over mountains – in one case was flying past the Magaliesburg mountains in South Africa’s Gauteng province. I was cruising at 140 knots on the leeward side – more than 5 nautical miles away and two thousand feet above the peaks. Suddenly  the plane rolled viciously 60 degrees to the right – hit by turbulence. I’d hit clean air turbulence courtesy of the mountains.

That was what is known as mountain waves and all pilots are wary of strong winds and flying in the vicinity of mountains, particularly down-wind where currents eddy and whirl like powerful ocean waves around rocks.

The BOAC flight had other strange facts. IT took off less than 24 hours after Canadian Pacific Airlines Flight 402 crashed and burned on landing at Tokyo’s Haneda airport. In fact in a chilling moment, passengers on BOAC speedbird flight 911 had looked out on the still smouldering wreckage of Flight 402 immediately before taking off for the last time.

The victims included a group of 75 Americans working for the Thermo King company of Minneapolis, Minnesota, on a two-week company sponsored tour of Japan and Southeast Asia.

There were 26 couples travelling together in the group, and 63 children were orphaned as a result of the accident.

In a macabre coincidence, five passengers cancelled their tickets at the last moment to see a ninja demonstration – they were researching a movie. The five were in Japan scouting locations for the fifth James Bond film called  You Only Live Twice.

Yes, truth is stranger than fiction.

With that slightly ominous fact ringing in our ears, it’s time to end. Please check out the blog Plane Crash Diaries which I’m sprucing up at the moment. You can send me messages through the site.

Next episode will cover fires in flight – and one of the examples will include South African Airways Flight 295 – a Boeing 747 that some say was carrying questionable cargo which caught fire leading to separation of the tail section and an in-flight break up.

Once again changes were made – IATA moved to end the practice of flying passengers on board aircraft that would also carry cargo. The so-called Boeing Combi type.

So until then, aviate, navigate and communicate safely.

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