"Back to ground school" I like it.
Absolutely correct but this diffrence is SMALL as acknowledged in my earlier
reply. One of the fastest Europas in Europe is also one of the heaviest. Its
easy to confirm just go out and fly your own aircraft full fuel two pilots
and then again half fuel one up. Yes it'll be slower two up but not much. I
would be interested to know what the difference is.
I've done some work on this but not enough. However my own results suggest
the difference on my own aircraft is less than 2 kts at 150 kts for a
difference in weight from 450 kgs down to 350 kgs (multiply by 2.2 if you
want lbs). Now thats not very much so I think I was correct to say weight
has only a small effect on speed. Using a cube rule that suggests a drag
reduction of 4% for a weight reduction of 29%. I don't think Kim saved 29%
of all up aircraft weight?
Try it for yourself and let me know what you get?
Jerry
LTS@avnet.co.uk
www.avnet.co.uk/touchdown
----- Original Message -----
From: "Rob Housman" <robh@hyperion-ef.com>
Subject: RE: Realalistic airspeeds
> Let's go back to ground school. To keep it simple, consider straight and
> level flight: additional weight requires more lift to balance the forces,
> but to generate more lift the wing's angle of attack must increase, and at
> greater angles of attack more drag is induced. To overcome the additional
> drag we have two choices (or a combination of the two): add power or
accept
> slower speed. Obviously things are not quite this simple because, for
> example, if we let the speed decrease that increases the induced drag but
> the parasitic and interference drag both decrease for a net reduction in
> drag (except in slow flight where the total drag increases as speed is
> reduced).
>
> A practical demonstration of the incremental improvement from weight
> reduction is provided by some airlines that go so far as to leave most of
> the fuselage unpainted, not because they like the look of shiny aluminum
but
> specifically to decrease fuel burn at cruise (lower weight, same speed,
> reduced power, lower fuel burn).
>
>
> Best regards,
>
> Rob Housman
> A070
>
>
> -----Original Message-----
> From: owner-europa@post.aviators.net
> Subject: Re: Realalistic airspeeds
>
> Not at all contraire. Building light greatly improves T/O and climb but I
> think has little effect on speed. Reducing drag increase speed but its
hard
> for me to see how Kim has acheived the sorts of reduction in drag
necassary
> to give the speeds that I have heard quoted. I didn't say he claimed to be
a
> deity, they never do, do they? He's clearly very talented and whilst his
> acheivments may set admirable targets for mere mortals I think it would be
> appropriate to make it clear that most builders (all that I know of so
far)
> fail to acheive anything like the figures acheived by Kim.
>
> Jerry
>
> LTS@avnet.co.uk
> www.avnet.co.uk/touchdown
> ----- Original Message -----
> From: "Rob Housman" <ROB-HOUSMAN@worldnet.att.net>
> "Karp" <karp@montrose.net>; <europa@avnet.co.uk>
> Subject: Re: Realalistic airspeeds
>
>
> > Au contraire, the performance of Kim's aircraft is indeed relevant for
the
> > rest of us even if it is only as a benchmark.
> >
> > Although Kim's build philosophy may include a religious attention to
> detail
> > he makes no claims to being a deity, and no god-like powers would be
> needed
> > to duplicate his accomplishments. It's all a matter of attitude.
N111EU
> > was built light, and incorporates drag reducing modifications beyond the
> > factory's speed kit, but any mortal builder could duplicate what Kim has
> > done. His aircraft may be relatively Spartan (emphasis on relatively,
> > because it is certainly not austere) compared to, for example, Dennis
> > Vories' XS (whose interior could be compared to a Lexus) but that's
> > essential to keeping it light. Since the proverbial free lunch still
does
> > not exist, each of us must choose to build light and go fast, or build
> plush
> > and sacrifice speed. Just because most builders seem to prefer to have
a
> > little more of the plush stuff that adds weight and decreases speed is
no
> > reason to exclude N111EU as a valid example of the Europa's performance.
> >
> >
> > Best regards,
> >
> > Rob Housman
> > A070
> >
> > ----- Original Message -----
> > From: "LTS" <lts@avnet.co.uk>
<karp@montrose.net>;
> > <europa@avnet.co.uk>
> > Subject: Re: Realalistic airspeeds
> >
> >
> > > I don't think looking at the performance of Kim Prout's aircraft is
> > > particularly helpful, unless you're a god. Nobody else seems to have
> come
> > > near to the performance acheieved by Kim!!!!! I think this guy wants
to
> > know
> > > what he can expect to acheive if he buys or builds a regular 914
Europa
> > Tri
> > > gear. There are several out there and we have sold props for at least
> two
> > > 914 trikes and one 914 mono. I am sure someone can give him typical
> > actuals.
> > >
> > > Jerry
> > >
> > > LTS@avnet.co.uk
> > > www.avnet.co.uk/touchdown
> > > ----- Original Message -----
> > > From: "Larry Graves" <larry@aircraftersllc.com>
> > > Subject: Re: Realalistic airspeeds
> > >
> > >
> > > > Although not a tri-gear, nor turbocharged, there is an excellent
> > > performance
> > > > evaluation of Kim Prout's Europa Classic at the following URL,
> requiring
> > > > Adobe Acrobat to open and read:
> > > >
> > > > http://www.cafefoundation.org/aprs/Europa%20APR.pdf
> > > >
> > > > Best Regards,
> > > >
> > > > Larry Graves
> > > > AirCrafters Builder Assistance Center
> > > > 140 Aviation Way, Watsonville, CA 95076
> > > > Tel: 831-722-9141 Fax: 831-722-9142
> > > > Website: www.AirCraftersLLC.com
> > > >
> > > > ----- Original Message -----
> > > > From: "Karp" <karp@montrose.net>
> > > > Subject: Realalistic airspeeds
> > > >
> > > >
> > > > Hi Everyone,
> > > > I am an experienced pilot who lives in the SW part of the United
> States.
> > > > I am very seriously looking at either Building or buying a completed
> > > Europa.
> > > > I am leaning towards the tri gear configuration.
> > > > I would prefer to use the turbo 914 version from Rotax, being that
> most
> > of
> > > > my flying would be around the mountains in the SW part of the US.
> > > >
> > > > If anyone on this list could give me some actual Airspeed and fuel
> > > > consumption numbers, other then the factory printed information, it
> > would
> > > be
> > > > greatly appreciated.
> > > >
> > > > Thank you,
> > > > Stan
> > > >
> > > >
> > > >
> > > > The Europa List is supported by Aviators Network UK -
info@avnet.co.uk
> > >
> > >
> > >
> > >
> >
> >
>
>
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