Safety
in F2D Combat
Summary and Evaluation of the Answers to the Questionnaire
We have received 57 answers from
22 countries including most of the countries with active
combat pilots. Many of the answers are from groups of people indicating
that the views and
remarks represent at least 90 pilots and others engaged in this
safety matter. Most answers give
remarks on almost all of the items in the questionnaire while
a few only have opinions about the
shut-off. There are also suggestions of other things to do or
to investigate more. These
suggestions can be found under the item Other.
In the questionnaire the introduction of a warning system was
mentioned but not listed as a
separate item. Due to conformity reasons in this summary it has
been included as an item of
itself.
Summary
Shut-off
An overwhelming majority of the answers are positive to the introduction
of shut-offs provided
that they get a sufficient time both to learn how to handle them
but also for developing them for
use with F2D models including how to start the reserve model when
there is no line tension.
Answers from those used to shut-offs in other Combat classes indicate
problems that need to be
solved.
Compared to a Fast Combat model and the type of shut-off used
there the F2D model have less
line tension (as well in the air as at take-off), bell-cranks
built into the wing, two models per heat
and matches that normally last for four minutes. Opinions also
indicate that effort should be used
to investigate if there are other types of shut-offs that can
be used instead of the types using line
tension.
Concerning the rules and how these should be formulated to deal
with shut-offs and the different
types of situations that can occur have no clear indication from
the answers. Matters to be dealt
with includes how to test the shut-off, what will happen if it
not works at a line break (damaged
or not damaged by a midair collision), if it shut-off due to no
or little line tension (but with the
lines intact), if the pilot cuts his own engine or if the engine
is cut by a tactical move from the
opponent.
Increased
line diameter
Everyone agrees on the fact that almost all kinds of lines can
be cut by any propeller but that
thicker lines can keep together better in a line tangle. A majority
are negative to an increased line
diameter as the lines would have higher weight therefore causing
a need for more tip weight but
also for introducing new problems with less drag and more collisions/line
tangles.
Decrease
the power of the engine
The answers only gave remarks of the three suggestions we brought
up to discussion with no
new ideas given. Many believe that changing the diameter of the
venture is obsolete as this cant
be done in an easy way on a lot of engine types. Introduce a minimum
diameter of the propeller
would also cause problems as the engines normally are made to
have a quite high rpm.
The easiest way due to the answers would be to decrease the output
of the silencer. This will also
reduce the noise (but that is another matter!). The overall conclusion
is that taking down the
speed of the model will take away the heart of the class as speed
is one of the fascinating sides of
F2D.
Change
the characteristics of the model
No one really believes that changing the models will have any
influence on fly-aways. It is also
an economical matter as there are a lot of models in use.
Change
the size of the engine
Almost no one believes this to be realistic due to the cost.
Increase
the 150 N pull test of the lines
Divergent views among the answers. One group claim that it is
ok to increase the pull test to 200
N as both carefully built models and proper lines easily will
stand the test. Others claim that they
have to build new models. One answer indicates that an increased
pull test can stress the lines
and damage them.
A majority are positive to a better visual inspection and giving
the organiser a right to ask a
competitor to change the lines although they passed the pull test.
Quality
of lines
Also divergent views. Some claim 4 strand lines to be better than
7 strand. Others claim the
opposite. Some claim that stainless steel lines should be banned
and others that they should be
mandatory.
One of the answers suggests that effort should be made to look
at new synthetically materials
and if they could be used as there are products on the market
that may withstand cuts from a
propeller.
One answer propose that the lines should be reinforced
or thicker where they are most likely to
break, i e near the handle or near the model.
Fuel.
Change or delete the nitromethane content
Most answers says that deleting the nitromethane would make the
engines both harder to start
and make them more critical for a good needle setting while a
few have no objections to deleting
this component.
The common opinion seems that changing the nitromethane content
will have no influence on
the number of fly-aways.
Having no nitromethane in the fuel makes it easy to test (with
an indicator paper/stick) if
someone tries to cheat.
Reduce
the radius of the centre circle
Also diverging opinions of this have any effect on the number
of fly-aways although the majority
is saying they can accept a smaller pilot circle.
Install
a safety net around the circle
Mostly positive answers to this question even if some answers
put the finger on the fact that
regional contests will have an economical problem with nets/fences.
As an alternative to have a 3 or 5 meter high net around the flying
circle (which would be the
best..) there are suggestions of fenced off spectator areas in
addition to signs warning for flying
models. Another brilliant idea is to use the football goals as
protective cages for time keepers,
other officials and spectators. Normally the contests are held
at a football ground and the goals
will therefore be easily available without any costly investment.
Personal
protection Helmets
Most find it strange that not all people (Jury, Team Managers
etc) being close to the circle are
mandated to wear helmets just like the pilots and the mechanics.
A few claim that this should be
voluntary for the persons involved.
Introduction
of a warning system
A lot of different views have come from the answers. Most agree
on the fact that stricter
judgement to make the pilots abandon the rough flying style will
have an influence on the
number of fly-aways. Opinion goes from using the current rules
more strict and DQ everyone not
behaving at once to introducing a warning system with yellow and
red cards.
Some suggests that both pilots should be disqualified if there
is a fly-away while others leave it
to the discretion of the Jury to punish one or both of the pilots
with a DQ in case of a fly-away.
Another suggestion is not to give a refly to a pilot that is on
the way of loosing at the time of the
fly-away as this will prevent loosing pilots from using a fly-away
to get a refly. Another thing to
do would to ask both pilots to land when a line tangle occurs
(maybe also stop the watches and
continue the match after untangling
.).
Other
Here you will find a short summary of different views mentioned
in all the answers.
Most answers express a worry that hastily taken rule changes might
ruin combat. As the problem
with fly-aways have existed for many years (and not increased
and not caused any serious
accidents so far) they dont see the need for a quick decision
instead of well thought-off rule
changes. The problem with fly-aways can be divided into two parts
where one is how to make it
safer when a fly-away occurs and the other of how to minimize
fly-aways (we can never
eliminate them!).
To make it safer when a fly-away occurs one can use shut-offs,
net or fence at the contest site
and helmets for all involved. A hemispherical net around and above
the circle would naturally be
the best but this is not feasible due to costs. Also a net around
the circle would cause high costs
(although you have it in T/R and Speed without protests).
A better way to go would be to have fenced off areas for spectators
etc in combination with shutoffs.
As pointed out there is still a lot of work to do before shut-offs
can be used in F2D. Not to
forget is the fact that a shut-off will take about 2 seconds to
cut and that the model will travel at
least 40 meters in this time. Therefore people near the circle
must be protected in other ways as
the shut-off will have a small or none effect in this area.
The general opinion is that changing characteristics of the engine,
lines or model will have small
or no effect on the number of fly-aways. Some answers implicates
that new problems can be
brought into F2D with if some of these changes will become reality.
The most effective way
seems to get pilots to change tactics and use a cleaner
flying style. This can be achieved by
stricter rules and by stricter judgement from the Jury.
One opinion express that introducing shut-offs will have a huge
influence of making F2D more
complicated and reduce the number of competitors in the class,
also making it more difficult for
new pilots to enter. A comparison is made with what happened in
the USA when shut-offs where
introduced. Instead it is proposed to change to smaller models
and an engine size of 1.5 cm3 as
these models will have a smaller mass and a lower speed thereby
making it safer without the
need of a shut-off.
One idea suggests the use of one or more horns. When dangerous
situations occurs in the bout
someone will blow the horn indicating to people around the circle
to be alert as a model can
come loose.
Another thing that should be addressed is the increased tactics
to use people standing outside the
circle signalling to the flying pilot that he is on his way to
loose and therefore need to take out
his opponent either by a crash or a fly-away. This is unsportsmanlike
behaviour and should be
dealt with.
To make it easier for the Jury to make decisions an official video
could be used.
One answer put the finger on the fact that many pilots use an
open-loop safety strap at the handle
instead of a self-locking construction as shown in the rules.
This open-loop system can in some
situations cause pilots to drop the handle (and model) as it opens
up.
One answer likes the rules to be simpler and that the power of
the Jury should be reduced.
Also that the increased cost should be considered as there are
a lot of people who might not
afford to continue or start with combat if models become more
complicated with shut-offs etc.
Evaluation (57 answers from 22 countries representing +90
persons)
Shut-off
41 answers more or less agree to a shut-off rule but states that
enough time must be
given to develop them before an introduction. There is a clear
indication that it will
not work just by using the Fast Combat shut-offs. Effort should
be put into the
question if there are other constructions that can be used. Great
consideration
should be taken when writing the rules dealing with situations
that can occur when
using shut-offs. An acceptable date for mandatory shut-offs seems
to be for the
World Champs in 2008 (1st of January 2008).
11 answers says no to shut-offs. Arguments are that they complicate
things, dont
work well enough or just will cause problems.
5 answers express no opinion.
Increased
line diameter
24 answers are negative to increase the line diameter in. One
argument is that it
would introduce new problems like less line tension etc.
21 answers are positive to increase the line diameter in. Some
answers suspect
other problems to be introduced. Even a plastic prop will cut
thicker lines but
thicker lines will stay together better in a line tangle.
12 answers express no opinion in.
Decrease
the power of the engine
18 answers dont want any changes at all. They claim that
these changes will have
no effect at all regarding fly-aways.
2 answers are positive to an overall change.
2 answers are positive to change the venture diameter.
5 answers are positive to have a minimum propeller diameter.
1 answer would like pressure tanks to be prohibited.
2 answers just express the opinion to slow down the speed of the
model.
10 answers are positive to reduce the outlet of the silencer.
It is pointed out that this
also will reduce the noise.
18 answers express no opinion.
Change
the characteristics of the model
32 answers are negative to any changes at all. They claim that
these changes will
have no effect at all regarding fly-aways. There is also an economical
matter if
models become obsolete.
2 answers are positive to changes.
23 answers express no opinion.
Change
the size of the engine
33 answers are negative to change the size of the engine. One
argument is that it
isnt realistic due to the cost involved.
1 answer says maybe
..
1 answer is positive to a change.
22 answers express no opinion.
Increase
the 150 N pull test of the lines
23 answers are positive to an increased pull test. Arguments are
that both the
models and the lines easily could stand a higher pull test and
that bad lines will be
sorted out.
10 answers are positive to stricter inspection.
11 answers dont like any changes in the pull test. Arguments
are that new models
have to be built and it could stress the lines (damage them).
21 answers express no opinion.
Quality
of lines
Very diverging opinions.
10 answers prefer a change to higher demands on the lines.
9 answers indicate that more effort must be made to find out the
best material or
type. Even look at other materials as synthetically ones.
8 answers prefer no change at all.
5 answers prefer 4 strand to 7 strand.
1 answeer prefer 7 strand to 4 strand.
24 answers express no opinion.
Fuel.
Change or delete the nitromethane content
22 answers would like to keep the fuel as it is. Deleting it will
have little influence
on the flying speed but make the engines harder to start and more
critical on the
setting.
5 answers want to delete the nitromethane. It will make the fuel
cheaper and one
(poisonous) component less to handle.
2 answers want to reduce the amount to 5%.
28 answers express no opinion.
Reduce
the radius of the centre circle
20 answers are positive to reduce the radius of the flying circle.
13 answers are negative to a change.
24 answers express no opinion.
Install
a safety net around the circle
22 answers are positive to have some sort of net/fence at the
contest site. If not
around all of the circle so at least a partial one for spectators.
7 answers are negative to have net or fences. One argument is
that it would
increase the cost for the organizer, especially at regional contests.
28 answers express no opinion.
Personal
protection Helmets
24 answers think that helmets should be mandatory for all people
around the
circle.
5 answers are negative to a rule and think it should be voluntary.
28 answers express no opinion.
One answer wants Ice-hockey helmets to be banned as they are unsafe.
Introduction
of a warning system
14 answers are positive to some sort of a warning system. There
are also an opinion
that there should be a more strict judgement against pilots with
a rough flying style.
5 answers are negative to a warning system.
2 answers express an opinion that it will have no influence to
decrease the number
of fly-aways.
36 answers express no opinion.
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