Comments by "Neil of Longbeck" (@neiloflongbeck5705) on "Mentour Now!" channel.

  1. Metal fatigue was discovered in 1837, long before the Wright brothers' parents were born.
    2
  2.  @TheScotsalan from my engineering materials notes. In 1842 William John Macquorn Rankine recognised the importance of stress concentrations in his investigation or railway axle failures. The following year Joseph Glynn identifies the keyway as the crack origin whilst investigating the failure of an railway axle. In 1849 Braithwaite was granted money bybthe British government to ascertain the effect of continuous changes in loads on iron structures in order to determine the max load that would not cause failure. He also coined the word fatigue in 1854 . Fairburn and Wohler undertake system research into fatigue in 1860, which lead Wohler to conclude in 1870 that it is the cyclic stress range rather than the peak stress that is the ruling factor in fatigue and came up with the term endurance limit. Sur James Ewing in 1903 that fatigue originates from microscopic cracks. Basquin in 1910 came up with the log-log relationship for S-N curves from Wohler's rest date. In 1954, the year if the Comet disasters, Coffin and Manson explain fatigue crack growth in terms of plastic strain in the tip of the crack (I can't say which came first). In 1970 Elber demonstrated the importance of crack closure on fatigue crack growth due to the wedging effect of plastic deformation, and finally in 1973 Briwn and Miller noticed that in multiaxial conditions the fatigue life of an objectbus governed by the direction receiving the most damage and that both tension and shear loads on the critical plane must be considered. As you can see the majority of the published work came before Comet.
    2
  3.  @TheScotsalan  only as far as it raised awareness of the subject and made engineers look at the fatigue lives of structures. The only research that I'm aware of that could be related to Comet was published 19 years after the disasters, the mutliaxis work as mentioned previously. The rest was based on the body of knowledge already amassed.
    2
  4. Good old J W Dunne.
    2
  5. You missed a bit of the story. It gets a bit James Bond. At the time they were designing the 247 Boeing did not have their windtunnel. The closest windtunnel were in California. The student running the tunnel Boeing was using to test the 247 design wanted to work in the aviation industry and so stole the test data and too, it to Douglas. Thus the DC-1 was also a cousin of the Boeing 247, which makes the DC-3 a second cousin once removed. Source: Widebody - the 747 story.
    1
  6.  @TheScotsalan  PS Milner in 1945 popularised the work of Palmgren's linear damage hypothesis of 1924 which can be used for fatigue life estimation.
    1
  7. During the Berlin Airlift a DC-3 was struggling to get airborne and to keep to time and altitude. After landing in Berlin it was discovered that it had been overloaded as it had been given the load for an Avro York. Shows just how capable the design was.
    1
  8. Sorry computers have always been involved in aircraft design. In the early days these were people who did the calculations for log tables etc.
    1
  9. The sign was put up by the Mayor IIRC. Boeing also suffered until the the Boeing Bust period of ha ing a large turnover of employees. They would get fully trained up and then quit.
    1
  10. Try 1907 for the first stable, controllable tailless powered aircraft with swept wings. It was even demonstrated in front of Orville Wright. Unfortunately Dunne's ill-health and WW1 prevent him from developing them further.
    1
  11. You need to check your captions match your script a bit better - says a foot short whilst caption say a foot longer.
    1
  12. He was just channeling the thoughts of J W Dunne, the true pioneer of tailless aircraft.
    1