- Apr 7, 2020
LolYour position, and the position I and others have been arguing against, is that you think all design originates with engine selection. Please don't try to change the focus of the debate.
Money was not the focus of my debate with you.
If you go back and read all my responses, and some others, to your posts it focuses on your assertion - Which. Is. Wrong. - that aircraft design STARTS with the engine. Also you say that the most powerful engine is always selected which is also totally false.
You even tried to wiggle out of being wrong by saying that the performance specs of the circulars to which the military designs responded HAD to have assumed the most powerful engine. But of course, as I pointed out, that's not DESIGN...that's SPECIFICATION and we are talking design. So that wriggle failed.
You use the fact that some designs used the most powerful engine available as proof, of your position, but it is not proof at all.
Topaz encapsulated that with this sentence a couple of posts above [emphasis mine]:
"Your basic assumption that the design mission is tailored around the "biggest engine I can find/afford" is what's flawed here.
Topaz also encapsulated the opinion that opposes yours, which I've been arguing all along:
"A genuine design process starts with the desired mission. Period. Full stop.
Above, mcrae0104 responds to you with this:
"Which of course, is not to say that I agree with the the position that one should always choose the most powerful, most advanced thing he possibly can choose."
I, and others, are responding to your assertion that engine selection drives design, and that the most powerful engine is always used. I am saying that is patently not true.
The mission comes first.
As one of my myriad of examples, I pointed out that if you were tasked to design an advanced trainer (the mission!) in the late 1930's (which resulted in the AT-6) you HAD TO start with the mission because if you didn't you wouldn't select the proper engine. You had engines ranging from Kinners and Rangers and 65hp engines that powered the J-3 (Continentals?) to R-2800's.
How could you POSSIBLY start with the engine given that range of performance UNLESS you KNEW what the mission was?
You just can't. After all you started with the task given you - the mission.
And I think you are willfully refusing to see that.
So now you try a different tack by saying "follow the money".
Part of 'the mission" is costs - when you are talking about civilian for sure and to some small degree military. It makes no sense to design a $5,000,000 general aviation trainer, so you wouldn't use
a GE F110-GE-129.
Because you KNOW the mission and you know that the mission doesn't need nor want that. You know the design would fail. You know that because you KNOW the mission: you know the price is too high, maintenance is too costly, and it's a stupid design for primary students.
But it's one of the most powerful engines out there! So by your logic the F110-GE-129 drives the trainer design.
After giving example after example of why you are wrong I gave up because it became clear to me your mind was shut. I listed a few here as one last attempt to see if your mind has opened a little.
Dang you are good.
really good you have me nodding my head in agreement.
and I start wondering how can that be. So I reread carefully I didn’t realize is that you’re putting words in my mouth imfact all along people have been arguing with a point that isn’t my point. Heck you even got me arguing off mypoint. (Collective You).
Let me quote again part of your first paragraph from the quoted post “ is that you think all design originates with engine selection”
Slipping That one little word in there “all” really changes things.
re-reading the opening post will actually be a good idea. What I was looking for was discussion of outstanding engines, It’s not the biggest but in every horsepower range.
Did Orville and Wilbur need the engines from the Apollo rockets? Of course not but Being able to use relatively light weight for their time engines enabled their mission.
Could we have flown the moon missions with the one on the Wright brothers used?
The mission was there millennia ago Jules Verne wrote about it but those engines where The key to go in to the moon. Being able to create those engines enable going to the moon the hope that we can create those engines drove a design that drove the creation of those engines.
Yes I get it that it’s somewhat circular logic but the available engines drive that circle to improve it.
there are lots of missions and aircraft designed for missions that will never be built because the engine needed doesn’t exist yet. But as soon as those engines exist the The designs start to become practical and the aircraft start to be built.
Can you see how that means engines drive design ?