SEN-461 August 29 2000
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News and Reports 2000 - second half
SCAT Electronic News 29 August 2000 issue 461
Table of Contents
=================
World cup "Jugo cup" - Raletic
Rules typo? - Markos
$200 cash for retrieval - Pearce
Fin Volume determination - Montes
NFFS News - Stalick
FAI Junior World Championship 2000 - Kaynes
World cup "Jugo cup"
====================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Dear Sir
i would like to inform you that information regarding " Jugo cup " which =
is a World Cup competition is available at =
http://solair.eunet.yu/~grofns/index.htm
I would appreciate if you could publish that information at SCAT NEWS.
Thank you and best regards
Milos Raletic
Rules typo?
===========
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
I came across this at our meet in Muncie over the weekend when I saw a
father winding for his son. It seems that if we want to employ a rule where
the contestant must wind the motor, an announcement in the bulletin or a
posting at the meet must be employed. I don't have a copy of the FAI rules
with me, but it would be interesting to note where who winds the motor is
covered. I also don't know exactly at what point in the rules cycles the
changes were made.
Chuck
-----Original Message-----
From: Steve Kaluf [mailto:This email address is being protected from spambots. You need JavaScript enabled to view it.]
Sent: Tuesday, August 29, 2000 8:04 AM
To: 'MARKOS, CHARLES S. [PHR/1825]'
Subject: RE: Rules typo?
Chuck, as I mentioned, even this type of correction, if that is what it is,
would require an proposal to make the change.
Steve Kaluf
Technical Director
-----Original Message-----
From: MARKOS, CHARLES S. [PHR/1825]
[mailto:This email address is being protected from spambots. You need JavaScript enabled to view it.]
Sent: Monday, August 28, 2000 12:29 PM
To: 'This email address is being protected from spambots. You need JavaScript enabled to view it.'
Subject: Rules typo?
Steve,
As I mentioned this morning by phone, the current rules do not state that
the contestant must wind the motor of his free flight model, except for
Indoor FF. The [almost] exact wording of paragraph 5 (1999 Rules) of the
General section states:
5. Preparation for flight. The flyer or proxy flyer must start
and regulate the engine of free flight models and operate the launching
device of free flight gliders....
However, the 1984-85 rule book statement under the same paragraph reads as
follows:
5. Preparation for flight. The flyer or proxy flyer must start
and regulate the engine of free flight powered models, wind the motor of
rubber models, and operate the launching apparatus of free flight gliders.
There are some minor wording changes in the 1984 and 1999 rules under this
paragraph, and I can envision a scenario where the revision process
inadvertently left out the part about winding the rubber motor. If so, the
rules were (in effect) changed without benefit of a rules change proposal
and should be fixed for the next publication. I suggest that you forward
this note to the FF competition board for action.
Chuck
$200 cash for retrieval
=======================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
EARN $200 CASH for two days of F1B retrieval for Fred Pearce at the U.S.
Team Selection
Trials being held Oct. 12 & 13 at Lost Hills. You must have a mechanically
sound chase motor
cycle.
Please contact Fred Pearce @ 713 747-3646
or e-mail Allen Brush: This email address is being protected from spambots. You need JavaScript enabled to view it..
Fin Volume determination
========================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
When designing an F1B, Coupe or other rubber powered models, the fin
area and and placement are not easy to determine. The related problem
of determining the stab area is solved in most cases by requiring that
the Tail Volume equals some number usually given by practice. Here:
Tail Volume = (Stab area x tail moment arm)/(Wing area x mean wing
chord)
Analyzing a number of successful F1B's it is seen that the Tail Volume
is normally comprised between 1.3 to 1.8, the larger figure belongs to
the AA inspired models, the lower belongs to the shorter PGI trim
models. However, a similar procedure is not available for determining
the area of the vertical fin or its optimum location. The problem is
obviously quite complex, as the fin has to provide lateral stability
under conditions that are widely variable, from the high torque
conditions of the initial burst to the glide at zero motor torque. The
fin provides the required moment in yaw so that the wing dihedral can
exert the proper motion in roll. This aspect of the stability in yaw was
lucidly explained many years ago by Frank Zaic and there is little to
add, except that we still have to determine the size of the fin that
will assure stability. An approach is suggested here that can provide a
starting point for determining the size of the fin. The fin area depends
on a number of geometrical and dynamical parameters of the model,as
stated above. In my opinion, the most important is the magnitude of wing
dihedral, although there are obviously others, such as motor torque,
location of wing (pylon height), placement of the fin ( behind the stab,
in front of, under the fuselage...), shape and side area of fuselage
which may have to be considered.
In a similar fashion with the Tail Volume, one can define a Fin Volume:
Fin Volume = ( Fin Area x Fin Moment arm)/(Wing Area x mean wing
chord)
where Fin Moment Arm = distance from the quarter chord of the fin to
the CG.
The Fin Volume is assumed to be related to the NDLA ( Non-dimensional
lateral area) parameter, formed by dividing the projected vertical area
of the wing: Total dihedral x mean chord by the wing area, or, what is
the same, total dihedral divided by span.
NDLA = (Total dihedral height x mean chord)/ Wing Area = Total
dihedral height/span
A number of new and old F1B models were analyzed in a plot of NDLA
versus the Fin Volume. This plot is shown in the attached Excel figure
where the points have the name of the modeller. The points are scattered
in a V formation, which many readers will recognize to be similar to the
stability diagram for full-size aircraft that is presented in some books
in aerodynamics. I have added two empirical lines that represent the
boundaries of stability. To the right of the diagram, the Fin Volume for
a given dihedral is excessive for stability and the model will be
spirally unstable. The fin action can overwhelm the stabilizing action
of the dihedral and the the model will dive in a steep spiral. To the
left of the diagram, the fin action is not quite strong enough to allow
the dihedral to stabilize the model and the flight pattern will show
oscillation about equilibrium (dutch roll), which is in any case
preferable to the other extreme. In-between these lines there is zone of
stability. Obviously, as motor torque has not been included in this
diagram, the graph is only an empirical aid for stability in glide. The
fin area will have to be adjusted afterwards to provide adequate torque
control.
As an example, take a typical total F1B dihedral of 110 mm and a span
of 1500 mm, for a wing area of 16 dm. sq. and a mean chord of 107 mm,
then the NDLA equals 0.073. For this value of NDLA the Fin Volume can
vary between approximately 0.25 to 0.5 for stability. For preliminary
computations, take a mean value of 0.38. Locating the quarter chord of
the fin at a distance 800 mm behind the CG, the fin area is determined
from:
Fin Volume= 0.38 = (Fin area x 800) /(16 x 107)
That is Fin area= 0.813 dm. sq. This fin can have a trapezoidal shape of
90 mm base chord, 45 mm. top chord and a height of 120 mm. Zeri and AA
can get by with smaller fins, near the left hand stability limit, some
of the older Wakes had much greater fin volumes. The trend of the
limiting lines seem to suggest that that a Fin Volume of 0.4 is stable
for a a very wide range of dihedral values, and thus could serve as
departure point for further refinement under flight conditions.
Comments and additions to this fin sizing diagram would be most welcome.
How is the torque and other factors taken into account by the
specialists? (Ton tour 007!)
Sergio Montes
Hobart, Tasmania, Australia
NFFS News
=========
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.
Hi, Roger:
All of the domestic patrons for the 2000 NFFS Symposium should have now
received their copies via Priority Mail. The overseas patrons will be getting
theirs shortly. If your readers have not ordered this year's Sympo, this is
the time to do so. They are for sale from NFFS Publications, % Bob McLinden,
3913 W. Temple Drive, Denver, CO 80236.
This 160 page publication, edited by F1B team member and assistant team
manager, Blake Jensen, sells to members for $25 per issue plus $4.00 for
shipping.
Also, the NFFS recently republished John Kaufmann's excellent 96 page book
"Flying Hand Lauch Gliders." This book is lavishly illustrated and covers
everything from balsa selection to thermal detection. The cost is $10 for
NFFS members and $12 for non-members plus postage or save postage and order
the Sympo and the HLG book at the same time. Order from NFFS Publications,
address above.
Thanks,
Bob Stalick, President NFFS
FAI Junior World Championship 2000 in class F1A
===============================================
Held at Sezimovo Usti, Czech Republic from August 14 to 19
1 Pawel Dorsz POL 1290 + 181
2 Jifi Chuboda CZE 1290 + 150
3 Elad Fish ISR 1290 + 132
4 Pavlo Bogach UKR 1290 + 56
5 Igor Bombek CRO 210 180 179 180 180 180 180 1289
6 Meir Klainer ISR 198 180 180 169 180 180 180 1267
7 Nicole van Eldik NED 210 180 180 180 180 180 128 1238
8 Lukasz Hubala POL 210 127 180 180 180 180 180 1237
9 Vladimir Dobychev RUS 181 180 180 180 154 180 180 1235
10 Daniel Bischoff GER 203 179 131 180 180 180 180 1233
11 Stephane Fleury FRA 210 180 180 174 180 127 180 1231
12 David Seren GER 210 180 116 180 180 180 180 1226
13 Szabolcs Redling HUN 150 180 180 180 180 180 169 1219
14 Elton Aliakbarov RUS 208 180 180 107 180 180 180 1215
15 Christinn Buchel GER 210 180 180 96 180 180 180 1206
16 Senad Cicak BIH 120 180 180 180 180 180 180 1200
16 Krisztian Kubasch HUN 120 180 180 180 180 180 180 1200
18 Alexandr Zastachkov RUS 210 180 180 180 84 180 180 1194
19 Nir Dahan ISR 207 180 180 180 180 180 86 1193
20 Michal Dvorak CZE 196 133 180 180 180 142 180 1191
21 Dallas Parker USA 210 180 78 180 180 180 170 1178
22 Emile Pitaud FRA 210 179 180 180 180 58 180 1167
23 Petr Hajek CZE 167 86 180 180 180 180 180 1153
24 Tomasz Burek POL 153 180 165 149 132 180 180 1139
25 Andrej Cigut SLO 147 180 180 84 180 180 180 1131
26 David Ellis USA 170 180 100 180 180 180 133 1123
27 Philippe Drapeau E/C 125 101 180 180 167 180 180 1113
28 Emir Golic BIH 142 180 180 180 180 69 180 1111
29 John Barron USA 187 180 180 180 180 180 0 1087
30 Yaroslav Artemenko UKR 210 180 180 96 180 35 180 1061
31 Jan Letko SVK 187 180 167 89 72 180 180 1055
32 Doris Ehrlich AUT 210 105 180 180 180 57 120 1032
33 Gregor Murovec SLO 65 166 180 180 180 46 180 997
34 Volodymyr Korjaka UKR 210 127 180 108 180 0 180 985
35 Bostjan Bagari SLO 17 106 180 180 180 180 129 972
36 Aurelien Pineau FRA 140 180 0 180 180 180 101 961
37 Roel Muller NED 135 62 141 180 180 56 180 934
38 Birgit Fuss AUT 120 180 122 102 180 46 91 841
39 Kenan Halilbasic BIH 124 53 180 64 180 52 180 833
40 Jouni Malm FIN 97 26 125 55 168 180 115 766
41 Juraj Cervelian SVK 74 122 180 69 39 86 180 750
42 Hannes Erkinger AUT 93 180 72 59 180 88 50 722
43 Stefan Pouwelson NED 96 99 143 119 68 75 73 673
Number of maximums 16 28 30 28 35 29 30
Number of full scores 16 12 9 6 5 5 4
Team Results
Country Abbreviation Total Team member places
1 Israel ISR 3750 3 6 19
2 Poland POL 3666 1 8 24
3 Germany GER 3665 10 12 15
4 Russia RUS 3644 9 14 18
5 Czech Republic CZE 3634 2 20 23
6 USA USA 3388 21 26 29
7 France FRA 3359 11 22 36
8 Ukraine UKR 3336 4 30 34
9 Bosnia Herzigovina BIH 3144 16 28 39
10 Slovenia SLO 3100 25 33 35
11 Netherlands NED 2845 7 37 43
12 Austria AUT 2595 32 38 42
13 Hungary HUN 2419 13 16
14 Slovakia SVK 1805 31 41
15 Croatia CRO 1289 5
16 Finland FIN 766 40
Results produced by Ian Kaynes
FAI Junior World Championship 2000 in class F1B
===============================================
1 Ivan Kolic YUG 1290 + 239
2 Marian Szafranski POL 1290 + 228
3 David Ellis USA 1290 + 217
4 Nikola Radosavijevic YUG 1290 + 203
5 Tomasz Moscinski POL 205 180 180 180 180 180 180 1285
6 Aurelien Pineau FRA 210 173 180 180 180 180 180 1283
7 Viktor Gopp GER 210 180 180 180 180 171 180 1281
8 Kamil Moscinski POL 210 151 180 180 180 180 180 1261
9 Ziv Bergev ISR 210 180 157 180 180 180 158 1245
10 Zbysek Nemec CZE 210 180 180 180 180 180 132 1242
11 Aleksander Marianovic YUG 210 180 161 180 180 180 150 1241
12 Artem Yardshuk UKR 210 180 125 180 180 180 180 1235
13 Vladislav Urban CZE 210 179 157 180 180 180 148 1234
14 Eran Shterebib ISR 210 150 153 180 180 180 167 1220
15 Kostjantin Abramenko UKR 210 180 180 124 180 180 145 1199
16 Benjamin Marquois FRA 210 180 99 180 180 180 166 1195
17 Ilia Doutov RUS 210 153 180 180 180 103 180 1186
18 Martin Mezihorak CZE 210 174 180 135 180 100 180 1159
19 Matvei Lechtchev RUS 210 180 93 180 180 180 133 1156
20 Aaron Arzamendi USA 210 168 155 139 180 133 149 1134
21 Gilad Varmaz ISR 154 180 101 167 180 180 139 1101
22 Pavlo Bogach UKR 210 161 180 180 16 180 114 1041
23 Thomas Behrendt GER 165 110 180 180 180 122 81 1018
24 Carsten Behrendt GER 106 180 93 180 180 180 88 1007
25 Emir Hajdarevic BIH 207 163 79 180 180 98 99 1006
26 Lea Marquois FRA 122 100 175 180 152 180 74 983
27 Midhat Uzunovic BIH 167 97 180 165 131 115 110 965
28 Predrag Sarkinovic BIH 90 180 92 180 180 87 119 928
29 Konstantin Tchantchikov RUS 190 0 126 180 180 180 10 866
Number of maximums 20 16 15 24 26 21 11
Number of full scores 20 12 7 6 6 5 4
Team Results
Country Abbreviation Total Team member places
1 Poland POL 3836 2 5 8
2 Yugoslavia YUG 3821 1 4 11
3 Czech Republic CZE 3635 10 13 18
4 Israel ISR 3566 9 14 21
5 Ukraine UKR 3475 12 15 22
6 France FRA 3461 6 16 26
7 Germany GER 3306 7 23 24
8 Russia RUS 3208 17 19 29
9 Bosnia Herzigovina BIH 2899 25 27 28
10 USA USA 2424 3 20
Results produced by Ian Kaynes
FAI Junior World Championship 2000 in class F1J
===============================================
1 Austin Gunder USA 690 + 300
2 Ilia Doutov RUS 690 + 188
3 Ivan Kolic YUG 690 + 184
4 Egor Kanakhine RUS 690 + 168
5 Oleksey Bogach UKR 690 + 102
6 Aleksander Marjanovic YUG 690 + 77
7 Oleksandr Verba UKR 210 120 120 104 120 674
8 Nikola Radosavljevic YUG 186 120 120 120 120 666
9 Lukasz Wysocki POL 210 103 120 87 120 640
10 Evgen Bashynskly UKR 144 120 120 120 120 624
10 Jaroslav Ivanov RUS 177 120 120 87 120 624
10 Marcin Kucharski POL 169 120 120 95 120 624
13 Marcin Koszman POL 95 109 50 120 120 494
Number of maximums 8 11 12 9 13
Number of full scores 8 7 7 6 6
Team Results
Country Abbreviation Total Team member places
1 Yugoslavia YUG 2046 3 6 8
2 Russia RUS 2004 2 4 10
3 Ukraine UKR 1988 5 7 10
4 Poland POL 1758 9 10 13
5 USA USA 690 1
Results produced by Ian Kaynes
.................
Roger Morrell
