Thanks for that Nigel=0AAs you say, fascinating! I'm glad my memory is not
so innacuarate after all!=0AGraham=0A=0A=0A=0A=0A__________________________
______=0A From: "nigel_graham@m-tecque.co.uk" <nigel_graham@m-tecque.co.uk>
=0ATo: europa-list@matronics.com =0ASent: Wednesday, 31 July 2013, 13:42=0A
Subject: Re: Europa-List: Tri-gear Flap Cross Tube Slot Length=0A =0A=0AA f
ascinating insight into the reasoning behind the recommendation for =0Athe
optimum flap setting can be found on page three of this early =0Afactory ne
wsletter, dated March 1994.=0AThis did of course relate to the first protot
ype, G-YURO, which was =0Apowered by the 80 horse 912 driving a fixed pitch
Warp Drive prop.=0A=0AHappy days. The enthusiasm and excitement was palpab
le.- Isn't it time =0Asomebody developed a new homebuild?=0A=0ANigel=0A
=0A=0A=0AOn 30/07/2013 10:23, Frans Veldman wrote:=0A> --> Europa-List mess
age posted by: Frans Veldman <frans@privatepilots.nl>=0A>=0A> On 07/29/2013
11:25 AM, GRAHAM SINGLETON wrote:=0A>=0A>> don't use 30 degree flap, Europ
a tested it and found you are starting to=0A>> lose aileron control at the
low speeds achieved in ground effect.=0A> I have some trouble believing thi
s (and even when it is true it is=0A> questionable whether this is still a
valid reason for the XS with the=0A> increased aileron span and with more p
owerfull engines).=0A>=0A> With higher flap settings you are getting more d
rag than additional=0A> lift. With 10% more flap (30 degree instead of 27)
you will get maybe=0A> just 5% more lift. If the ailerons are inadequate fo
r this tiny bit of=0A> extra lift I think they would have difficulties hand
ling 27 degrees as=0A> well. Furthermore, in the XS the ailerons are substa
ntially increased in=0A> lenght, significantly more than 5%, and should hav
e much more control=0A> power at low speeds! Even if control problems were
the limiting factor,=0A> than it is questionable whether the same limit wou
ld still be needed for=0A> the XS.=0A>=0A> I thought that the limitation in
flap was because of the 80hp engine=0A> used for the certification, which
might have lacked sufficient power to=0A> exercise a go around with full fl
aps under full load (which is, if I=0A> remember correctly, a certification
requirement. For the same reason the=0A> older Cessna's have 40 degree fla
ps, where the newer ones have 30 degree=0A> which was instantly rewarded wi
th a 30Kg higher MTOW without any=0A> structural changes).=0A>=0A> Furtherm
ore, in the tri gear the fact that you have the option to use 30=0A> degree
flaps doesn't mean that you will have to use this all the time.=0A> There
are situations where more flap would be welcome, and there might=0A> be sit
uations where using less flap would be better. I can't see the=0A> benefit
of the 26 degree limit. Of course for the mono you have no other=0A> option
than to land with full flaps, so maybe in this case the=0A> limitation is
justified.=0A>=0A> I know folks having drilled a new hole in the lugs on th
e flap control=0A> tube, so that the actuator can drive the flap further (a
nd faster). No=0A> control difficulties are observed even in quite a few na
sty situations=0A> with 30 knots wind and lots of turbulence. Instead the s
hort field=0A> capabilities are somewhat improved.=0A>=0A> Regards,=0A> Fra
ns=0A>=0A>=0A>=0A>=0A>=0A>
|