Frans
and all of you:
I woke upp last night and got a light like a
lightning to my poor salesman brains.
That was well before your message below.
I have not visited my Europa and that is not
necessary because of this question.
You - Frans - are absolutely right!
My mistake:
I thought Europa=B4s tailplanes are like any other
ordinary elevators.
Because it=B4s natur to be all flying I understood
it is very light to operate but I did not
understand the real meaning of "aerodynamically
balanced".
I have always thought as follows: fore of the
torque tube there is about 1/3 of tailplanes and
behind there are 2/3 of tailplanes.
That is why I have assumed there are aerodynamical
forces but only let is say 2/3 - 1/3 = 1/3 when
compared to "normal" solution like Cessna=B4s
elevator.
Finally now I understand the name of the game:
without the antiservo function pitch would be
totally w/o forces in the stick!
Awful!
When trimming that means we are in fact in-lining
tailplanes with trimtabs to a certain desired
position!
I got some messages which were supporting my idea
and for example Mr X from Z wrote
"Now lets increase our speed to say 140 kts in
straight and level flight
without trimming . . . . . you and I both know
that we will require a
forward pressure on the stick which of course is a
pain so we need to trim
the tailplane so that aerodynamic forces are
substitued for our mussle
power. Now if Frans is correct, the trim tab will
once again be aligned
with the trailing edge of the tailplane so what
the hell is providing the
necessary force to hold the tailplane in the new
position? The tab simply
MUST be displaced to provide the necessary force
to my way of thinking."
That was exactly what I thought also.
And answer is: there is NO necessary need for any
force to hold the tailplane in the new position
because it is happy with ANY position.
That is why they (tailplanes and trim tabs) are
always in-lined when trimmed properly.
When trimming - you are in fact cleaning the
entire system!!!
The most genious part: what is keeping it there in
the desired position?
If the tailplanes try to move upp or down, trim
tabs move automatically even more to same
direction and that is why the are fixed just that
position where pilot has trimmed them.
And they stay here until new trimming or pilot
force via stick.
That is why I feel a bit or more frightened also:
without antiservo function there would be not att
all any idea what is the position of the
tailplanes!!!
No stick forces at all!!!
Before flight I have always checked my tabs but
---From this point I will do it very carefully!!!
Without them or that function I assume Europa will
be a flying coffin.
Until now I am happy I did that mod (mandatory in
England) which enhanced trim tabs=B4s pins years
ago!!!
I remember I almost cancelled because I was
tempted to imagine those trim tabs are nice but
not totally necessary for safety!!!
One interesting point also: obviously all the
tailplanes which have been built perfectly, are
perfectly also aerodynamically balanced.
Like Frans=B4s Europa=B4s tailplanes.
Then and only then the trim tabs are always lined
with tailplanes when properly trimmed!!!
My Europa and many other Europa=B4s trim tabs are
(when watching photos) slightly deflected when
cruising and the plane is trimmed.
That means those tailplanes are not perfectly
built = they are not perfectly aerodynamically
balanced.
Obviously it is hard to produce perfect shaped
tailplanes when making foam tailplanes like mine
but next generation tailplanes without foam
structure are maybe "automatically" perfect.
Frans, thanks for patience.
Frans, thanks for educating me and some other
persons on the globe.
Frans, thanks for you because now I understand a
bit more my plane and respect it much more.
I did not feel at all
"Someone pointed out to me that he found my post
"condescending". "
They say some Dutch people are a bit arrogant but
you - Frans - are not. Just brilliant. I am
pround we are in the same list and fly same plane.
***
OK. I am a Donald Duck. Kwaak kwaak kwaa.
But I am a happy duck. That is because
- my nephews are talent.
- I have a nice career in a fat factory.
- my uncle (Scrooge) have some nice jets, bush
planes, DC-3 and many others and I am able to fly
them all, also IFR in Alaska through snow storms.
- my uncle is the richiest duck in the world and
some day I will be his heir.
- my girlfriend Iines Duck is very atractive.
- my daughters love Donald D.
Frans - next time I will consider a bit more
before I think you are wrong.
You are wrong probably very seldom, I assume.
Would be nice to meet you in Texel next autumn.
I give you some extra present: have you earlier
seen a Duck on the wing behind a running star
engine?
Raimo (cheekbones totally red) aka DD
Terveisin, Raimo Toivio
Europa XS Mono OH-XRT #417
37500 Lemp=E4=E4l=E4
p +358-3-3753 777
f +358-3-3753 100
toivio@fly.to
www.rwm.fi
--------------------------------------------------
From: "Frans Veldman" <frans@privatepilots.nl>
Sent: Wednesday, May 12, 2010 10:25 PM
Subject: Re: Europa-List: Re: Effects of Flaps and
Ailerons on Pitch Trim
> <frans@privatepilots.nl>
>
> On 05/12/2010 05:17 PM, Donald Duck wrote:
>
>> What faster we fly that more we get lift by
>> wings.
>> That is why we have to push more or trim nose
>> down = trim tabs move upp
>> when flying faster.
>> The stabilators=B4 trailing edges move then down.
>
> YES! And the story doesn't end here.
> Now, before we go any further, print this out,
> and take it with you to
> the hangar.
>
> Are you there? Fine.
> 1) Put the trim in the middle, and line up the
> tailplane and anti servo
> tab by rotating the tailplane. If done properly,
> the tailplane is in
> about its "neutral" position when it lines up
> with the anti servo tab.
> 2) Now, trim the nose down with your trim
> button. Anti servo tabs moves
> up (assuming you wired everything correctly).
> 3) Let's play aerodynamics. Your hand is the
> airstream. The anti servo
> trim "sticks out" in the airstream. Push with
> your hand on the anti
> servo tab to imitate the aerodynamic forces.
> 4) Now LOOK! The anti servo tab goes down. Due
> to some ingenious
> mechanical linking the trailing edge of the
> tailplane also moves down
> (this is why you trimmed the nose down after
> all).
> But most important: The anti servo tab moves
> faster down than the
> tailplane. While pushing the anti servo tab
> downward, it will at some
> moment be in line with the tailplane. Stop when
> you reach that moment.
> This is your newly trimmed out position!
> 5) Now stare at it for a while, and consider
> what you just did. Try it
> the other way around.
> 6) Start wondering why the anti servo tab would
> remain sticking out in
> the airstream by itself while nobody is keeping
> it there. Also try
> moving the trailing edge of the tailplane down
> without the anti servo
> tab moving twice as fast downwards as well. It
> can't be done!
> 7) Congratulations! You just discovered that an
> anti servo tab is not a
> regular trim tab! A regular trim tab is held in
> a fixed position and has
> no choice. An anti servo tab can move, seek the
> most convenient
> position, and as a consequence take the
> tailplane with it.
>
>> They have to be un-lined normally, more or
>> less!
>>
>> If not I am a Donald Duck!
>
> Quack. :-D
>
>> That is why we usually and almost always see
>> them (trimtabs) in
>> deflected position only.
>> I am sure you will confirm that when you get
>> take more photos.
>
> If the opportunity exists, I will show it to you
> so you can see it with
> your own eyes.
>
> Frans
>
>
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