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Old 10-17-2021, 07:48 PM
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Igo kyu Igo kyu is offline
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Originally Posted by JacksonsGhost View Post
I see what you're saying Igo kyu. If a designer is given a certain powerplant to work with and they produce a design that is overweight for the powerplant you could say that their design is overloaded, and that may be their own silly fault.
You are correct, that is what I'm talking about.

However, in common aviation terms, if you are calling an aircraft underpowered or overloaded I believe those terms mean two different things. An overloaded aircraft is usually one which is operating above its design weight, or at least above its design weight for a given situation. In comparison, an underpowered aircraft is usually one which lacks performance at or below its design weight.
Well, I get what you are saying with the latter, and "overloaded" may be a less than helpful word, but it seems to me that if the design was specified to use a particular powerplant, and is underpowered with that powerplant, the fault is in the design, not the powerplant.

And for the latter case, the cause may well be, as you suggest, the fault of the designer. It may also be the fault of whoever insisted on adding extra weight/drag to their design prior to production.
I am thinking that the case of people outside the designer adding extra constraints is part of the design process, the actual designer may have done the best they could with what they were given, but the design was faulty despite that.

Or in some cases the engines that the airframes were designed for just didn't come up to expectations, but were used anyway until something better was available.
There were certainly engines that did not reach their intended performance, I would not include aircraft afflicted with those among those I am talking about.

And finally, use of the term underpowered can be a relative thing. What was considered reasonably powered at the beginning of a design process, may be considered underpowered compared to other aircraft by the time it reaches production.
That is not what I'm talking about really, there is a trade-off between lift and speed, if you aim for too much speed you won't get enough lift, and vice versa which is really what I am interested in discussing. If an aircraft achives a reasonable speed considering it's powerplant, that's sort of good enough but a lot that flew early in the war didn't achieve that. It's probably more often a case of over optimistic specifications than designer incompetance, but there were a lot of slow heavy aircraft that could and should have been lighter and faster. Of course, sometimes speed wasn't important and time aloft was, and there were aircraft rightly optimised for that.

Of course if you are flying an aircraft which is both underpowered and overloaded then just taking off and landing safely may be a challenge!
Yep, though probably more taking off than landing.
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