My dad rode a triumph thunderbird up the runway at Farnborough i the early '50s, at 100mph. He worked for a steel erection firm who did work for the air ministry. Studying this videos to see if i can spot him among the spectators.
@ Metal fatigue was not as well understood then as it is today. Maybe folk should do a little basic research before making themselves sound foolish. The jet transportation age began on May 5, 1952, when the de Havilland Comet 1 began scheduled flights from London to Johannesburg. Britain’s de Havilland Comet began commercial jet service in 1952. The aircraft and the service it provided had captured the world’s attention, including that of US aircraft manufacturers, whom it now appeared, were well behind their competition. The aircraft’s reputation was tarnished, though, when less than two years after the jet started its record-breaking service, two Comets disintegrated in flight within three months of each other. An under-test Comet was pressurized to 2 times the in-service maximum pressure, and that caused the metal around some holes to get cold-worked, and thus delay cracking. The test results were misleading. The other major unknown was the change in the aluminum alloy behavior after “cold working.” This is the beneficial effect of putting a high stress on the aluminum in the factor 2 safety testing, which actually changed the properties of the metal, making it more resistant to fatigue. Because the company did their fatigue testing on the fuselage which had been pre-stressed at factor 2 safety margin, the material could withstand 16,000 cycles whereas the ordinary metal without pre-stress failed nearer 1000 cycles. They should have carried out fatigue testing on a new fuselage, rather than using the proof-tested sample. This story illustrates the problem of applying the stress criterion and arbitrary factors of safety when using a material whose toughness can change rather easily under certain conditions. A fragment of one broken Comet is in the Science museum, indicating the huge effort which went into recovery of the parts, diligent testing of the pressurization problem, and ultimate description of the fatigue cracking failure process. The government ordered a full investigation at the Royal Aircraft Establishment, establishing a court of enquiry to report on the cracks, later found to be caused by fatigue processes initiated by rivet holes, near corners of windows, for example, where stress was raised. The crashed Comets had failures starting at those very holes. Of course, there was a lot more. The investigation of these crashes quickly focused on fatigue and, after eliminating a wing failure as the cause, a full scale fatigue test of the fuselage soon revealed that the fatal failure sequence was caused by cracks emanating from countersunk fastener holes immediately adjacent to severe radii corners at windows and escape hatches (Wanhill, 2002).
The Brabazon was cancelled as were many others. The Comet was unsafe. The UK went into decline and is no longer a significant power, laying in Europe's offshore.
Many others benefitted from the Comet experience. Boeing did for the 707. Your comment is wrong on many counts. Canberra? Lightning? Vulcan? Victor? Buccaneer? Hunter? Harrier? Other countries have their problems - Starfighter? Brabazon of course was a mistake, as are most things specified by a committee living in the past! Princess too!
@@DrivermanO The person you are responding to may well be Willber Finnigan. A well known hater of anything UK. I reckon he's an offshore, plastice paddy. You notice that he doesn't mention the Canberra?
@@mauricedyer6842 It was the Americans and Russians who destroyed the Nazi regime. Not little Britain. And what is wrong with speaking German? Millions and millions of people do.
El actual y decadente Reino Unido, viviendo del pasado. Ahora dedicado a alentar al comediante retrógrado de Zelensky, porque nunca han tenido cojones para enfrentar solo a Rusia, y como siempre haciendo el trabajo indigno, de espiar para su amo los Estados unidos.
Big old airshows beautiful
Amazing
My dad rode a triumph thunderbird up the runway at Farnborough i the early '50s, at 100mph.
He worked for a steel erection firm who did work for the air ministry.
Studying this videos to see if i can spot him among the spectators.
Good old technology
The British aircraft manufacturers demonstrated impressive innovation and enterprise in those days. What happened?
Too many companies chasing too little money, customers (AirMin, BOAC/BEA) not knowing what they wanted or changing their mind. Hubris to a degree.
Accountants and Politicians happened.
@ Yes, you have a point there.
Maybe they shouldn't have made out that the comet was the future when it was a death trap.
@ Metal fatigue was not as well understood then as it is today. Maybe folk should do a little basic research before making themselves sound foolish. The jet transportation age began on May 5, 1952, when the de Havilland Comet 1 began scheduled flights from London to Johannesburg.
Britain’s de Havilland Comet began commercial jet service in 1952. The aircraft and the service it provided had captured the world’s attention, including that of US aircraft manufacturers, whom it now appeared, were well behind their competition. The aircraft’s reputation was tarnished, though, when less than two years after the jet started its record-breaking service, two Comets disintegrated in flight within three months of each other.
An under-test Comet was pressurized to 2 times the in-service maximum pressure, and that caused the metal around some holes to get cold-worked, and thus delay cracking. The test results were misleading. The other major unknown was the change in the aluminum alloy behavior after “cold working.” This is the beneficial effect of putting a high stress on the aluminum in the factor 2 safety testing, which actually changed the properties of the metal, making it more resistant to fatigue. Because the company did their fatigue testing on the fuselage which had been pre-stressed at factor 2 safety margin, the material could withstand 16,000 cycles whereas the ordinary metal without pre-stress failed nearer 1000 cycles. They should have carried out fatigue testing on a new fuselage, rather than using the proof-tested sample. This story illustrates the problem of applying the stress criterion and arbitrary factors of safety when using a material whose toughness can change rather easily under certain conditions.
A fragment of one broken Comet is in the Science museum, indicating the huge effort which went into recovery of the parts, diligent testing of the pressurization problem, and ultimate description of the fatigue cracking failure process. The government ordered a full investigation at the Royal Aircraft Establishment, establishing a court of enquiry to report on the cracks, later found to be caused by fatigue processes initiated by rivet holes, near corners of windows, for example, where stress was raised.
The crashed Comets had failures starting at those very holes.
Of course, there was a lot more.
The investigation of these crashes quickly focused on fatigue and, after eliminating a wing failure as the cause, a full scale fatigue test of the fuselage soon revealed that the fatal failure sequence was caused by cracks emanating from countersunk fastener holes immediately adjacent to severe radii corners at windows and escape hatches (Wanhill, 2002).
J'ai cru reconnaître Adolf Galland sur la vidéo 🤔
Shame. The iconic Spitfire had already become largely obsolete by this time, less than a decade after the Second World War had ended.
The Avro 707 - not to be confused with something out of the US a decade later.
The Brabazon was cancelled as were many others. The Comet was unsafe. The UK went into decline and is no longer a significant power, laying in Europe's offshore.
Many others benefitted from the Comet experience. Boeing did for the 707. Your comment is wrong on many counts. Canberra? Lightning? Vulcan? Victor? Buccaneer? Hunter? Harrier? Other countries have their problems - Starfighter? Brabazon of course was a mistake, as are most things specified by a committee living in the past! Princess too!
@@DrivermanO The person you are responding to may well be Willber Finnigan. A well known hater of anything UK. I reckon he's an offshore, plastice paddy. You notice that he doesn't mention the Canberra?
@@user-xl7zx1vm2n What the people of Europe should not forget is, if it wasn't for Great Britain and her allies: they would be speaking German
@@mauricedyer6842 It was the Americans and Russians who destroyed the Nazi regime. Not little Britain. And what is wrong with speaking German? Millions and millions of people do.
@ Where are these aircraft and their descendants now?
El actual y decadente Reino Unido, viviendo del pasado. Ahora dedicado a alentar al comediante retrógrado de Zelensky, porque nunca han tenido cojones para enfrentar solo a Rusia, y como siempre haciendo el trabajo indigno, de espiar para su amo los Estados unidos.