Raptor Composite Aircraft

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by Dexacare, Mar 28, 2016.

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  1. Jun 28, 2019 #841

    lvaero

    lvaero

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    Sacrfices weren't par for the course at CalTech or Embry-Riddle either, but that was just about the funniest thing we read today!
     
  2. Jun 28, 2019 #842

    lvaero

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    Engineering humor of the day!
     
  3. Jun 28, 2019 #843

    lvaero

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    Hence the reason for the 40 hour restriction!
     
  4. Jun 28, 2019 #844

    BBerson

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    Yet the owner is required to sign section 3 of the application and "certify" that the aircraft was inspected and is "airworthy", before the first flight.
    It seems to me the application should instead say "has been inspected and found eligible for a 40 hour test flight permit to determine if airworthy". It should only then be signed "airworthy" after the 40 hour inspection.

    This would be especially appropriate for new prototypes or self designs. This would allow major alterations as needed without repeated DAR or FAA checks.
     
    Last edited: Jun 28, 2019
  5. Jun 28, 2019 #845

    Deuelly

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    The FAA's definition of airworthy is basically a part, component or aircraft that is "in a condition of safe operation". In a condition of safe operation basically means that the paperwork was done correctly. They could care less at that point if it flies like a turd or will even get in the air. If something goes wrong they have a division for that too.
     
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  6. Jun 28, 2019 #846

    lvaero

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    Its an E-AB aircraft. If its a bespoke design, its already implied to the FAA that the designer has done their due diligence in the design process. Also, the aircraft only goes through a DAR / FAA reinspect if there were outstanding discrepancies that needed correction in order to satisfy the inspectors.

    40 hours to determine airworthiness? I assume you mean 40 hours to determine flying qualities and performance characteristics?

    We have been involved in E-AB development across the pond as well as here in the US. Not an easy task out there. To get a build permit, our client had to present, literally, hundreds of pages of engineering documentation we were hired to produce, proving the design was aerodynamically and structurally sound. Then, once our client completed the build a few years later, he then had to once again retain our services for flight testing. The poor guy couldn't even take his own design aloft on its maiden flight!

    Is that what you want here?

    To a point, we can agree with your view, but if our government took the same stance as the LBA or EASA, it could have a seriously adverse effect on our community, especially considering the good safety record E-ABs have.

    If you want to do your own design, but don't have the requisite knowledge or skill set to do it right, then hire it. No shame in that at all!!
     
  7. Jun 28, 2019 #847

    BBerson

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    I think the definition is " complies with type certificate and in a condition for safe operation".
    Neither can be determined for a new design EA-B before the needed test flights.

    To the comments above, I am suggesting a method for less FAA oversight of prototypes. In the beginning, the FAA (CAA) did all condition inspections. The trend is less FAA oversight. I don't think the FAA is more qualified than the designer to determine airworthiness. What has been reported in this thread is they more or less rubber stamp. They could more credibly sign a permit to fly instead of a statement of "airworthy".
     
    Last edited: Jun 28, 2019
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  8. Jun 28, 2019 #848

    lvaero

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    That does make logical sense, but, from a legal symantics view, that is precisely what the restricted airworthiness certificate and the distance restriction is for...it is strictly for testing the design out before the aircraft is considered "fully airworthy". This is how it was explained to us from a FSDO some years ago.

    That being said, we have bore witness to inspectors that have "rubber stamped" a build inspection, simply because "everything looks really good", while we have seen others that more or less amounted to a "significant and traumatic emotional event", because the inspector went so overboard into detail, even going as far as wanting to see material purchase receipts and even at one point asking the builder to demonstrate one of the techniques described in his build log. The builders decision to get us involved in that mess actually planted the seeds for the formation of our business back in 2009!

    We are currently training a client on how to properly test her (yes, her) new creation when the time comes. Our curriculum details multi-phase test planning and execution, with emphasis on data reduction & interpretation in addition to flight safety and risk management. We are a huge proponent of brief "runway flights" during the high speed taxi phase, especially for a bespoke design. It answers alot of questions before the "official" first flight.
     
    Last edited: Jun 28, 2019
  9. Jun 28, 2019 #849

    BBerson

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    Well that's the sort of testing I want to be free to do. A single brief runway flight would give me enough to determine if I need to go back to the drawing board and/or try a different engine. But a brief runway flight isn't legal without an airworthiness certificate. And the freedom from airworthiness certificates is a strong incentive for going with FAR103.
    I just don't feel my single seat test flight freedom choices should be so carefully limited.
     
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  10. Jun 28, 2019 #850

    lvaero

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    Again, that is where education and training come into play.

    Our view is that if a builder has to make a major modification, not talking about a flight control re-rig or avionics adjustment or weight shift, but something significant like a change of engine as you suggest, then something has gone horribly wrong.

    You seem to be contradicting yourself. On one hand, you seem to be wanting some heavy engineering oversight on amateur designers and builders on the part of the FAA, in the name of safety, then you say you want the opposite.

    In the E-AB world, at least here in the US, you can darn-near literally do whatever you want. Its the very essence of innovation. You are not held to the high standards required of full certification, but, you can hold yourself there if you want. If the FAA did not think this was safe or otherwise permissable, I can assure you that guys like Burt Rutan, Jim Bede, Jack Northrop, Mike Arnold, et al would never have been known to the world, and who knows, the state of the art in aerospace would be nowhere near where it is today.

    Who is telling you that you have to skip the crawl-walk parts of flight testing? If you have to do a billion runway hops before you're comfortable going up, there is absolutely nothing stopping you. If you go over the 40 hour restriction, that is fine too. You test at the level of safety and comfort you feel appropriate. NEVER let anyone tell you or compel you to do otherwise.

    I assume you have read the following?:

    https://www.faa.gov/aircraft/gen_av/ultralights/amateur_built/aw/

    https://www.ecfr.gov/cgi-bin/text-i...f2d39c55&mc=true&node=se14.2.91_1319&rgn=div8
     
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  11. Jun 28, 2019 #851

    BBerson

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    Never said I would want more oversight. For me, I would like no oversight for my light single seat category experiments. But that isn't likely, so something like the UK SSDR category would suit me, I think.
    But this is getting off topic....
     
  12. Jun 28, 2019 #852

    Topaz

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    Let's not pretend. He's going to try and fly it himself. He knows he's going to try and fly it, and we know he's going to try and fly it. It'll lift off and do a crow-hop, and he'll use the "successful" completion of that event as rationalization to "just take it around the pattern," and so on until Bad Things Happen.
     
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  13. Jun 28, 2019 #853

    bmcj

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    You went a little off topic with this post Topaz... it has very little to do with the FAA E-AB sign-offs, engineering degrees, or virgin sacrifices we have been discussing here... oh wait, my bad, this thread IS about the Raptor.

    Nevermind... carry on.
     
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  14. Jun 28, 2019 #854

    wsimpso1

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    Eeew! Illegal and immoral too. Eeew!
     
  15. Jun 28, 2019 #855

    wsimpso1

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    They did not have that class at Michigan (Go Blue!) in the late 1970's or 1980's. Well, not in the engine school anyway. At Chrysler (FCA) we did have a form in circulation where we appealed for a waiver of Laws of Physics. All with a wink-wink, nudge-nudge of course.

    Billski
     
  16. Jun 28, 2019 #856

    wsimpso1

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    I hit google too, and the ONLY citation is this thread.

    I just read Marc's comment to my multiply degreed engineer wife, and she says she never heard of anything like this at Virginia Tech or Penn State or in the Harry Potter books.

    Billski
     
  17. Jun 28, 2019 #857

    wsimpso1

    wsimpso1

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    "this will end badly" from "The Dead don't Die"
     
  18. Jun 28, 2019 #858

    BJC

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    I believe that Hermschmitdt is a distant relative of George P. Burdell.


    BJC
     
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  19. Jun 28, 2019 #859

    foolonthehill

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    That's what killed Richard Hogan and destroyed the Commutercraft ship. I spoke with Richard weekly about the status of his test pilot(s), and waiting for their availability. I spoke with him about the desgners emotional attachment to his creation, the, "I created this, built it from nothing, surely it would never hurt me" mentality. I told him test pilots don't have that emotional attachment, and therefore much less is at risk for both them and the aircraft. It was the last conversation I had with him three days before he died. Yet in the end, after one brief flight by his test pilot, and then making a number of changes without any real data to support them, he decided he was going to fly his aircraft. For three minutes, he did.
     
  20. Jun 28, 2019 #860

    rv6ejguy

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    Anyone know which airport the plane is based at now?
     

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