10/23 Raptor Video

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231TC

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Yeah, I was thinking it might have been a good idea to test that when he had 8,000 feet of runway to work with, but that was just one more in a long string of headshakers.
 

flywheel1935

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I,m a tad confused . So the Raptor is already the weight of a VW Beetle overweight , so why add another 50lbs ???
Its gross weight was probably plucked out of the ether anyway, as PM seems to be dyslexic when it comes to numbers ,there, any number that comes into his head must have become its AUW ??? If from the outset he must have worked out a suitable wing loading??? then take five adults + baggage + Fuel + weight of engine & PRU, then what's left must be what the airframe needs to weigh. For an IT guy , guess he used an abacus?
 

rv6ejguy

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I think you can only really appreciate how important weight management is on an aircraft project by building one before designing your own the first time. Outside of structural integrity and adequate flight stability, weight is a very critical factor in successful airplane design. With no formal structural design background to lean on, most of us would tend to build something heavier than it needs to be in order to be safe. Even using TLAR methods means you need previous experience to judge what is safe and light so you know what actually looks about right.

Airframe design is best done by real engineers or at least copying known safe designs with minimal mods.

Raptor could have essentially copied the Velocity basic structure and layup schedule allowing for carbon instead of glass and it could/ should have used an existing six cylinder aero engine. These two things alone would probably have shaved an easy 500 pounds off what PM ended up with.

Now when you set out to build something lighter and faster than existing designs in this league, you NEED some real engineers involved IMO. You can't wing it and think Solid Works will make you smarter and better than those with decades of experience doing this stuff. Airplane design isn't like building a deck for your house.
 
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Geraldc

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I think you can only really appreciate how important weight management is on an aircraft project by building one before designing your own the first time. Outside of structural integrity and adequate flight stability, weight is a very critical factor in successful airplane design. With no formal structural design background to lean on, most of us would tend to build something heavier than it needs to be in order to be safe. Even using TLAR methods means you need previous experience to judge what is safe and light so you know what actually looks about right.

Airframe design is best done by real engineers or at least copying known safe designs with minimal mods.

Raptor could have essentially copied the Velocity basic structure and layup schedule allowing for carbon instead of glass and it could/ should have used an existing six cylinder aero engine. These two things alone would probably have shaved an easy 500 pounds off what PM ended up with.

Now when you set out to build something lighter and faster than existing designs in this league, you NEED some real engineers involved IMO. You can't wing it and think Solid Works will make you smarter and better than those with decades of experiencing doing this stuff. Airplane design isn't like building a deck for your house.
Or you could use the Colin Chapman of Lotus racing car design approach and make things lighter until they broke .Any bit of metal that could fit a lightening hole got one.
Things breaking is not good for aircraft though.
 

wsimpso1

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Or you could use the Colin Chapman of Lotus racing car design approach and make things lighter until they broke .Any bit of metal that could fit a lightening hole got one.
Things breaking is not good for aircraft though.
Chapman made cars fast by making them light. But there is too much as well. Stirling Moss, Jimmy Clark, Jochen Rindt, Graham Hill, Mario Andretti all had major accidents due to overly light construction, killed World Champions Clark and Rindt, significantly contributed to Moss' retirement. Identical accidents at the same corner broke World Champion Graham Hill's leg but left Mario only slightly injured.
 
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zolotiyeruki

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In building the 4 seat Bearhawk, I drilled lightning holes in the outside door frames and saved 8 lbs that It will never have to carry.
I wonder if the same technique could be applied to the Affordaplane, and how much weight savings could be found
 

Wanttaja

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So when folks are extremely competent in their area of expertise and education, then resistance to random BS from the peanut gallery is both understandable and expected. And some extremely competent engineers that I've known have had that attitude. However, I'll put in a plug for Burt Rutan here, in that he was always willing to listen to comments and criticism from his engineers. Now, if all you had was hand waving, Burt's hand waving would win 99.996% of the time - he had enough experience in enough areas that he'd almost always be able to estimate what was going on with a few hand calcs, if not just thought calcs.
...other good stuff, which I completely agree with, deleted.

Have to keep in mind, though, that true insight into a designer's genius (or otherwise) is only gained in retrospect. Few probably anticipated Burt Rutan would become a design legend the day he completed the first VariViggen. There were people who believed Dr. William Christmas was a brilliant designer. We'll have to revisit PM and the Raptor five, or even ten years from now. No doubt this thread will still be going. :)

[Probably apocryphal story] They once asked Mao Tse Tung what he thought of the French Revolution. He replied, "Too soon to say".

Ron Wanttaja
 

speedracer

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I think you can only really appreciate how important weight management is on an aircraft project by building one before designing your own the first time. Outside of structural integrity and adequate flight stability, weight is a very critical factor in successful airplane design. With no formal structural design background to lean on, most of us would tend to build something heavier than it needs to be in order to be safe. Even using TLAR methods means you need previous experience to judge what is safe and light so you know what actually looks about right.

Airframe design is best done by real engineers or at least copying known safe designs with minimal mods.

Raptor could have essentially copied the Velocity basic structure and layup schedule allowing for carbon instead of glass and it could/ should have used an existing six cylinder aero engine. These two things alone would probably have shaved an easy 500 pounds off what PM ended up with.

Now when you set out to build something lighter and faster than existing designs in this league, you NEED some real engineers involved IMO. You can't wing it and think Solid Works will make you smarter and better than those with decades of experience doing this stuff. Airplane design isn't like building a deck for your house.
I read somewhere that the three main criteria for airplane design is weight, weight..... and weight. (Lack of).
 

Marc Zeitlin

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Have to keep in mind, though, that true insight into a designer's genius (or otherwise) is only gained in retrospect. Few probably anticipated Burt Rutan would become a design legend the day he completed the first VariViggen.
That's true. But whomever was around to look at it almost certainly didn't say (or think to themselves) "what a piece of crap - you're going to kill yourself in it, and you really don't have a freaking clue what you're on about, do you?"

We'll have to revisit PM and the Raptor five, or even ten years from now. No doubt this thread will still be going. :)
No doubt...

[Probably apocryphal story] They once asked Mao Tse Tung what he thought of the French Revolution. He replied, "Too soon to say".
Zhou Enlai, morphed into Mao Zedong, apparently. See:

 
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Erik Snyman

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That's true. But whomever was around to look at it almost certainly didn't say (or think to themselves) "what a piece of crap - you're going to kill yourself in it, and you really don't have a freaking clue what you're on about, do you?"

No doubt...

Zhou Enlai, morphed into Mao Zedong, apparently. See:

Like the question reportedly asked to Mahatma Ghandi:
Q: What do you think about Western Civilization?
A: That would be a great idea.
Erik in Oz.
 

flywheel1935

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I guess the highlight of this years Oshkosh is the arrival of Mike Patey and Scrappy, a chap who over performs at every level, and produces both quality design and execution of his ideas based on proven engineering and outstanding attention to detail.

In a strange way I feel sorry for PM, who is not only not displaying the Raptor, but also will never achieve the level of skill in fulfilling his dream machine that homebuilders not only expect in kit design but also now demand. His overhyped presentation several years ago is probably now well forgotten as the dream that turned into the nightmare that the project has become.???

Many years ago I used to be a freelance race mechanic and as a sideline built up Caterham/lotus 7 kits on behalf of the owners. This was the perfect example of kit supply, all parts pre packed in alphabetical order start at A ,get to Z and drive it home.
I guess this is almost the default option for kit aircraft that are marketed today.

Exactly 38 years ago, on this day, I arrived at Oshkosh and have never attended an aviation event that was so inspiring. I even ended up importing the very first Snyder Paraplane back into the UK and enjoyed many happy hours flying fixed and rotary aircraft over the years.
I think that a Raptor may well never attend Oshkosh in the future, as the project fades into history, & gathers dust in some far flung hangar and aviation moves on.
 
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