Hawkjet?

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Dana

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Looks like somebody took a T-38, chopped the tail shorter and added a v-tail and longer wings.

-Dana

"Naked" means you ain't got no clothes on; "nekkid" means you ain't got no clothes on - and are up to somethin'.
 

skeeter_ca

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The pictures make it look alot smaller. Till i saw the spec's a thought it was a single place maybe slightly bigger than a BD-5j.

skeeter
 

orion

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Another typical jet design project - not very realistic but sure has lots of CAD pictures. Also seems to take a fairly free license with other makes, using their pictures to frame his web site. I'm not impressed.
 

brian121

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Orion I'm kind of curious what is realistic about a aircraft in this size class?
I would also like to know where he is going to find a Williams FJ44? the only small fanjet engines
I've seen lately are PW610's and they are on the market only because Citation owners are converting to the Williams engines.

Brian.
 

mcmurphy

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According to the specs the empty weight is 1500 lbs. and the dry weight of the engine is 452 lbs. If these figures are correct that gives us a difference of 1048 lbs. Not much considering you are going to need to stuff a lot of equipment into it. Such as a retractable gear mechanism, oxygen systems, full dual controls and instrument panels, an airframe beefy enough to handle high-speed loads and some aerobatic ability...
 

orion

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Well Brian, I did say that it's not very realistic and reading through his pages and the proposed specs, I'd classify this as another "pie in the sky" venture with no grasp of reality nor jet airplane design experience. And personally I think it's rather ungainly to say the least.

Regarding the Williams, first off, I know the company does not support any "Experimental" programs in any way, with the exception of them going to immediate certification. In that case they will lease you an engine but you are required to obtain a sufficient insurance policy for the engine and also place a deposit for ten production engines at the same time (the latter came from the owner of the SportJet program who initially did use the Williams engine). And one final note - the program owner is highly optimistic about the cost of one of these Williams engines: They're not $200k - more like two or more times that. And I think the P & W engines are in the same ballpark.

In short, somewhat pretty web site but don't hold your breath.
 

HawkJET

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I'd classify this as another "pie in the sky" venture with no grasp of reality nor jet airplane design experience. And personally I think it's rather ungainly to say the least.
It is interesting to read everyone's comments. It appears that there are egos in this arena that are quite large.

I looked at your website and I can see that many of the things you say about me could also apply to you, based on the limited information one gleans from such media. You imply that you read through my website, but in checking my web logs, you maybe read three of the thirteen or so pages. Many of your comments are addressed in the site.

Also, I personally would talk to somebody (or at least communicate in some fashion) to understand their thought processes. You may find that I have looked into the very things you bring up and have arrived at my own solution.

Plus, you may have some valuable insight you could provide, but your ego seems to be in the way and you don't seem interested in contributing to a fellow aviator. I am clear there are things about the HawkJET I cannot achieve in a vacuum. I look for assistance in many areas. You may be a valuable resource, but not with your approach.

If you have questions or comments, I suggest you be straight about it and go to the source. You may find that I actually have some good ideas myself (and even some creative solutions). And heaven forbid, YOU may even learn something new.:gig:
 
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addaon

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Heh... while I have no doubt Orion, like all of us, can always learn something new, he's the wrong one to accuse of having an ego getting in the way of his contributions. He's by far the most important and influential contributor on this forum.
 

orion

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Part of the reason I tend to come down hard on some presentations, especially jet ones, is because I've seen so many failures over the years and most folks who try to develop this type of hardware have a tendency to repeat the same mistakes over and over again. Patterns in this industry don't lie and do tend to be very accurate predictors of future potential. Furthermore, patterns or approaches associated with design practices have the same predictable characteristics - simply said, thirty years of looking at various approaches to jet design (and the fact that that's the part of the mainstream industry I come from) allows me to make fairly accurate guesses as to where a program is going and its future viability (technical or otherwise). You can call that ego if you like - I just tend to call it as I see it. Being politically correct or beating about the bush helps no one - I find most of my customers prefer blunt; it tends to save them a lot of money and time. It is true I can (and often do) always learn from others but that learning better have a solid basis and track record.
 

HawkJET

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Taking your points slightly out of order:
I just tend to call it as I see it. Being politically correct or beating about the bush helps no one - I find most of my customers prefer blunt; it tends to save them a lot of money and time.
I'm 100 % with you on this.
I've seen so many failures over the years and most folks who try to develop this type of hardware have a tendency to repeat the same mistakes over and over again.
Please point out these mistakes! The following isn't helpful at all:
Another typical jet design project - not very realistic but sure has lots of CAD pictures.
Either is this:
I'd classify this as another "pie in the sky" venture with no grasp of reality nor jet airplane design experience.
Nor this:
And personally I think it's rather ungainly to say the least.
Furthermore, patterns or approaches associated with design practices have the same predictable characteristics
Again, please point out these patterns or approaches!

You can call that ego if you like
It is one thing to be "matter-of-fact" and blunt. It is quite another to be demeaning! If you had presented anything to support your demeaning comments, I may overlook your inflated ego. But you DON'T!

It is true I can (and often do) always learn from others but that learning better have a solid basis and track record.
So let's turn this around. How many airplanes have you built? How many were jets?

Orion, I actually don't care if you have ever built an airplane, let alone a jet. If I learn something new from you, I don't care about your track record. A good idea is a good idea no matter what the source. There are many things that I learned PRECISELY because the source of the instruction did NOT have a track record. Doing things over and over (having a track record) gives one tunnel vision. Someone without tunnel vision has a wider perspective!

I have no doubt that you could give me some valuable insight. I request you do exactly that and quit your petty insults.
 

Inverted Vantage

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He's not really throwing around any petty insults at you, like you seem to be doing towards him. He was critiquing your project; not you. So far all you have done has been the opposite. Perhaps you could provide some counterpoints to the things he's brought up, as opposed to attacking his "ego"?
 

HawkJET

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He was critiquing your project; not you. So far all you have done has been the opposite.
Yes, these are clearly critiques of my project:
"Another typical jet design project - not very realistic but sure has lots of CAD pictures. "
"I'd classify this as another "pie in the sky" venture with no grasp of reality nor jet airplane design experience. "
"And personally I think it's rather ungainly to say the least."

If he had a project in this thread to critique, I'd be happy to. I am just calling him on the carpet for what he said about mine.

Perhaps you could provide some counterpoints to the things he's brought up
How, exactly, would you suggest I counter those points??? There are no points! What, SPECIFICALLY isn't realistic?? I suppose I should have made apple pie instead of cherry pie?? If I left the pie on the table it wouldn't be in the sky? Ungainly? I don't get it.

What ARE you talking about??????????
 

Inverted Vantage

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Yes, these are clearly critiques of my project:
"Another typical jet design project - not very realistic but sure has lots of CAD pictures. "
"I'd classify this as another "pie in the sky" venture with no grasp of reality nor jet airplane design experience. "
"And personally I think it's rather ungainly to say the least."
Yes, that is a critique of your project. That's how critiques work. If you really do think your project is worth it, defend it; explain how it's realistic, and explain how it has a firm grip on reality.

How, exactly, would you suggest I counter those points??? There are no points! What, SPECIFICALLY isn't realistic?? I suppose I should have made apple pie instead of cherry pie?? If I left the pie on the table it wouldn't be in the sky? Ungainly? I don't get it.

What ARE you talking about??????????
How about providing some of the evidence behind all those CAD drawings? Perhaps some airfoil data, design analysis, etc? Maybe even some information on how you plan to purchase your chosen engine for such an amazingly low price?

Not hard to defend your concept if it's worth defending, rather than getting angry and attacking the individual who's simply saying that he doesn't believe what you're doing will work.
 

mike_t_12

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I would be interested in hearing more about the engine as well. On your website you state -

"The FJ44 has an excellent service record and there are enough in the field (over 1,000) that it's likely there are used engines readily available at a reasonable price. As a result, this is the engine selected for the HawkJET™. "

Have you been able to purchase an engine yet? How about engineering support? Have you talked to Williams about engineering support with respect to technical details related to installing and operating one of their engines?
 

addaon

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Yep. The explicit concerns that have been brought up for this particular project are (a) engine availability, price, and integration and (b) realism of empty weight. The standard concerns for generic jet projects are (c) fuel capacity and associated range and (d) structural analysis with focus on flutter (which is particularly interesting with your forward swept wing).

The comments about the web page are more along the lines of it being unclear what analysis has been done to justify the specification claims or design choices. For example, you show a close-up of a wing cuff; but you don't explain why that's the best way to accomplish (presumably) tip stall reduction in this case, nor why you think it's either necessary or sufficient. You also claim that "adhesive bonding methods" will be used instead of riveting, without explaining how you're going to handle the pitfalls in this approach.

In general, there's not enough information provided to distinguish your proposal from a standard BOTE sketch done over a weekend; that's not to say that it won't mature, or that you don't have more information on your own. But surely you can see why it's not terribly more exciting - to us, with the information we have - than the dozens of similar projects that have gone nowhere.
 
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