Hi Ira,
In the more regulated UK world I suspect Europa did quite a bit of flight
testing to arrive at the take off flap setting of 18 deg. quoted in the
section 5 of their Owners Manual. Regarding CFD I know that the current
Europa (Swift) had a bit of trouble getting the Europa form into their
computer as some of it was originally designed and built using Nigel
Graham's CAD system ( Cardboard Aided Design).
Regards
Brian Davies
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of rampil
Sent: 09 August 2015 02:09
Subject: Europa-List: Re: Takeoff technique and runway minima (trigear)
Hi Richard,
Yes.
When I was based at latitude 41N and had a 4500 concrete runway at sea
level, I never used flaps for T/O. Never had a performance issue, but I will
admit to not carefully collecting flight test data on take off run. Sadly,
my BlueMountain data logging feature was discontinued in my G4 making new
collection more onerous.
At latitude 33 where the average temp feels 20F warmer, more humid, and
starting at 900' AGL, my habit is to use a small amount of flap on my grass
strip. Recall that with our flaps, lift increases in the early part of
travel and less in the late travel whereas drag increases mostly in the late
travel. Without flight test and therefore only my opinion/experience
5 - 10 of flaps increases lift (and minimally at t/o speed, induced drag)
and minimally increases form drag. Perhaps at half flap the lift is maxed
out without too much extra drag, I would think at 19 you are getting more
drag without much more lift. My strip is far too rough to take careful
measurements, but perhaps Europa could try a wee bit of CFD since they have
the form data and the software.
Cheers,
--------
Ira N224XS
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http://forums.matronics.com/viewtopic.php?p=445712#445712
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