XPost: or.politics, alt.politics.trump, alt.fan.rush-limbaugh   
   XPost: alt.astronomy, rec.aviation.military   
   From: pothead@snakebite.com   
      
   On 2024-07-03, Jim Wilkins  wrote:   
   > "R Kym Horsell"  wrote in message   
   > news:v62l3f$1r7h$4@nnrp.usenet.blueworldhosting.com...   
   >   
   > According to the contract they had to test them in a certain way the   
   > company officials considered a big old waste of time and money.   
   > If a fauly was detected the whole test rig was SUPPOSED to be shut down   
   > and colled off, then re-started and the controller had to the get up   
   > to speed then pass the test. The company method was to just keep going   
   > until the controller passed the tests and ignore any failures along the way.   
   >   
   > ------------------------------   
   >   
   > I was in the industrial testing business for a while. "Test until pass"   
   > wasn't an uncommon practice, there's enough random variation in repeated   
   > test results to somewhat justify it, and the fail limit may be arbitrarily   
   > overcautious. It may have been set by Marketing to look good on a spec   
   > sheet, and you won't go to jail for setting it too high but you might for   
   > setting it too low. When weight doesn't matter much the safety factor is   
   > typically at least 3 to 5, while in aviation it may be 1.5. For the steel   
   > chain I just bought it's either 3 or 4 depending on grade, I don't know why   
   > the difference. Chain rated to hold 6600 Lbs in use is tested during   
   > production at 13,200 and expected to break at 26,400.   
   >   
   > In one case I found a timing bug in the test station's computer microcode   
   > that caused occasional failures which didn't repeat when the part was   
   > retested, so passing it through a second time was the procedure. The test   
   > was the problem, not the component. My reward was being assigned to a new   
   > product's development team. Unfortunately such small highly specialized   
   > companies go broke or at least lay off the engineering staff when capital   
   > investment in new equipment vanishes during a recession.   
   >   
   > The experience I gained there in high speed computer controlled measurement   
   > positioned me well when the increasing speed of analog to digital converters   
   > made digital radio practical. By then I had a stronger background in   
   > computer hardware design than the radio engineers.   
   >   
   > The designer of the Japanese Zero fighter couldn't achieve the specified   
   > performance without reducing the strength margin to 1.5x the expected load   
   > to save weight, and others followed. The pilots were ordered not to dive   
   > faster than 350 kts because the lightly built wings would fail at higher   
   > speed. He knew because a diving plane had ripped apart and killed the test   
   > pilot while he was watching. Improving high speed performance would have   
   > added weight and cost some low speed maneuverability, which the authorities   
   > considered more important to win a dogfight. British pilots learned the hard   
   > way that even a Spitfire couldn't dogfight a Zero, though they were   
   > vulnerable at high speed. I read that an F-15 can sometimes outmaneuver an   
   > F-16 because the computer controlled F-16 has an angle of attack limiter   
   > while the F-15 doesn't, and can be pushed closer to a stall. The pilot is   
   > expected to handle the danger.   
   >   
      
   Both of you are spot on. I have several friends who worked for Grumman   
   (manufacturer of the LEM and   
   various fighter jets)  and they used to tell similar tales.   
      
   It's all about risk vs reward and believe me they have departments that study   
   the risk vs reward of   
   every bolt and nut that is used on these advanced aircraft. If the risk   
   increases 2% by using a   
   cheaper bolt but the reward, also known as cost, goes down 10%, the cheaper   
   bolt gets the job   
   assuming no other factors are involved.   
      
   Still it comes down to following the money and not being the whistle blower.   
   Even with the   
   protections in place for those who expose issues, their career is usually   
   torpedoed anyway.   
      
   Personally these days I wouldn't set foot on an airplane much less a spaceship.   
   And that goes triple for anything Boeing builds.   
      
      
   --   
   pothead   
   Joe Biden is the absolute WORST President Of the U.S. ever.   
   Nobody else is even close. Including Jimmy Carter.   
   Vote for ANYBODY but Joe Biden in 2024.   
      
   --- SoupGate-DOS v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)