The
memorial log by LOLO |
Right figure you can
see one of my first altitude logs.
LoLo was in my midsize
hotliner Optima II. Wing span 1250mm (49" ), 12 cells Sanyo 1250SCR,
brushless Phasor 30-3, prop Aeronaut CamCarbon 10x6.
Sure I was happy that
design is finished and my intention was to test it hard.
In forth climbing
you can see I reached height 536m. I had BIG BIG problems to control such
small airplane in this altitude...
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On 5/7/2002 Friday
afternoon in Holic (Slovakia). Day before Czech and Slovak F3B Championship.
This is altitude log
from my flight with BigSting alias Caligulla (3.15m). Hard to explain
experience from this flight but anyhow it was heartbreaking!!
The highest descent
(average from 5 adjacent values) was -74m/s eg. 270km/h. Sure speed of
BigSting was higher while it was not possible to fall down from the sky
just apeak.
I guess a descent
angle around 60-70 deg. and the speed could be somewhere near 400 km/h?
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Tuning
trailing edge deflection for launching of F3F,F3B and F3J |
But the main reason
why I speak about LoLo are pure silent flight disciplines; F3B, F3J and
F3F (my interest).
Here I found LoLo's
services invaluable. Right figure you can see for example start analysis
of my New Sting
I was tuning trailing
edge deflection. It was evident that too much flaps and ailerons doesn't
work.
Optimum was somewhere
nearby 6-7mm trailing edge, interesting. Good to know.
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Start analysis. Here
I made already some formatting and zooming in Excel.
As you can see here
is sampling rate of LoLo 0.3s.
For start is better
to switch to 0.1s sampling rate.
A bit more detailed
view to one start. Sampling rate of altimeter was switched to 0.1s. Good
for start analysis.
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Also interesting graph.
It's speed record.
Note peaks on turning bases A or B (red arrows).
There is quite interesting
"ballast" product of pressure sensor.
You can see when I
was turning while G was so high that sensor produced altitude increase
which marked turning.
Sure (or hopefully;-)
I was heading down when turning, not up...
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Altitude
in thermal duration |
Just ordinary thermaling
You are falling down after launch and after 3 minutes there is hot air
allotment for you. When I was in point A, I guessed height about 600-700m,
New Sting was really small. No, it was mistake! Only cca 220m!
Thanks to a bit stronger
wind I was circling down the wind and I was more far from me than higher.
Interesting! Using protractor we could calculate (some trigonometry) distance
on the ground and in the air.
Just circling is tedious
therefore there is point B, switching to Speed Phase and a little bit
whistling :))
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Getting
Optimum Gliding ratio |
This was tough day.
My intention was to be on the airfiled before sunrise. It 's getting up
around 4:00 8-)
But it was again quite
interesting experience with my F3B/F3F ship and altimeter.
Using more trailing
edge down increased time in the air significantly but up to certain point-sure
expected.
But where is this
point? Altimeter helped me to find it exactly.
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Dynamic
Soaring Analysis |
Dynamic Soaring, perhaps
the youngest discipline of F3X guys.
Yeahh, I also tried
this heartbreaking temptation.
Sure I don't fly without
LoLo even on slope side and therefore you can see altitude log from my
first DS attempt.
In first half of log
you can see my trials when zooming behind the slope but after fourth air
raid I was starting to DS!!!
Wouuuu!!
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Let's look
to this picture a little bit in details. I made zoom in using Excel and
a bit of math should help me to ROUGHLY guess the speed of DS.
- From graph we can
guess average diameter of DS circle. I guessed 35m.
- Let's say average
duration of one circle is 5s.
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- I guessed the angle
alpha was 60 degrees. See picture
- Resulting speed
was guessed about 170km/h (105mph) See picture
It's clear that these method is very(?) inaccurate, but gives me rough
idea what's going on in the air. Needles to point out for instance that
I was DS more or less under me (negative altitude), but from altitude
log you see only positive values. High G are perhaps resulting mentioned
offset of altitude. Hopefully absolute value of height is similar to real
altitude but only shifted up. Would be very interesting to compare this
calculation with "real life" radar gun measurements...
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