Evening Frans
My seals are all on the top surface and the hinge line of the rudder. I
agree with you about the effect on the stall speed but was not prepared to
argue the case - at the time I just wanted to get the aeroplane flying. They
did not actually say no just that we would have to do a lot of flight
testing.
I will be most interested to hear the results of your stall speed tests. I
would have expected hot and high to have had an opposite effect on
performance.
My rudder is also a poor fit at the bottom, the fuselage is too wide, how
ever it is probably in turbulent air off the prop.
Regards
Pete
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Frans Veldman
Sent: 30 July 2012 16:29
Subject: Re: Europa-List: Mylar seals and stall speed?
Hi Pete,
> I have had the Mylar gap seals since new in 2003. Mine were fitted to the
> flap gap, as well as the ailerons and rudder, but my inspector was not
happy
> and checked with the PFA/LAA. They were not happy either about possible
> effects on the stall speed and the seals were removed from the flap gap
> before the first flight.
I can imagine someone fearing that the stall speed increases... but here
the stall speed decreases. Is that a bad thing, to lower the stall speed?
Isn't that the holy grail of wing design, to lower the stall speed
without hurting the cruise and top end performance?
I can imagine that with heavy cross wind the airplane keeps flaring
beyond the point where the rudder can keep the plane straight. This
might be more of a problem for the mono than for the tri-gear. For the
tri gear one can opt to land with the flaps up or partially deployed if
a higher stall speed is desired.
At the next occasion I will do some checks to see if indeed the stall
speed has been affected by these seals. I didn't know that a STOL-kit
was so easy to make for an Europa. :-)
Oh, and I just assumed that with seals on the flap gap you mean seals on
the upperside of the wing. Not on the huge gap on the lowerside of the
wing, right? In the latter case, I can see how that could increase the
stall speed as you effectively change the fowler flaps into non-fowler
flaps. I didn't apply seals on the lowerside of the wing for exactly
this reason.
Do you still have the seals on the rudder? I only did the starboard
side, because at the port side the gap opens up quite a bit with full
right rudder, and the seals might be sucked inside the gap and block the
rudder. I would like to hear if someone indeed tried seals on the port
side of the rudder. I have quite a nasty transition there as the rudder
is less wide than the rear of the fuselage. I would love to smooth out
this transition but I'm not going to be the one who finds out whether
this is a good idea or not. ;-)
Frans
--
This message has been scanned for viruses and
dangerous content by Houxou, and is
believed to be clean.
|