SEN 2865 Where are you on the altimeter field?

SEN 2865

Where are you on the altimeter field?

1. Question for Allard
2. Altimeters and beyond
3. On flying 1km upwind
4. Where was the F1X on the field?
5. SEN

Question for Allard

From: Ed skorepa
Obviously, timer keeper will have to verify that altimeter reads ZERO m with an airplane placed on the ground just before the launch. How will they do that?

ed skorepa

Editor’s comment. I understand that the way the altimeter works is that it detects the moment of launch and uses the altitude it measures at that point as the base. The readings are then taken relative to the point. Also the device has a green LED that show any previous reading that has been cleared that the time keeper can check. Allard can confirm this.

Altimeters and beyond

From:Urs Schaller
Thank you Stuart for having summarized in a few, excellent sentences the problem(s) and motivations we have to tackle.

Talking as an elder modeller, I remember the day I decided to do FreeFlight because it was different from other sports, it was full circle and you had to deal with BOM rule, aerodynamic, meteorology, construction and many more. Not just (bought) javelin throwing!

On the other side Allard reminds us to consider seriously the duty’s we face because other’s like to use the airspace we considered “ours”. In addition, they like to use airspace for commercial purposes and as always, it is hard to argue against money. Probably on the base of these restrictions, altimeters and GPS will be included in the FF models of tomorrow.

However, that does not yet mean they have to be used for the essential part of the competition, the timing. They may help not violating the legal boundaries. Nevertheless, timing should remain as is with all the shortcomings included. As Pierre writes, otherwise we have to rewrite a complete new set of rules.

On my part, to preserve the “sportsman”, I will follow the original dream of a sport in which results origins from my personal work and not from my wallet or other.


On flying 1km upwind

From:Allard van Wallene

Some of the arguments against the use of altimetry tend to the conviction of free flight being a luck game where bad luck is just part of the equation we have to (must?) live with.
An inexperienced near sighted time keeper assigned to you without bino’s.
Your model flying behind a tree line while others don’t.
Your model flying into the only downdraft on the field.
Your model DT’ing early because your clockwork timer decided to run fast or not DT-ing at all.
So if this luck game aspect is so important to these sportsmen, then why did they change to e-timers? Why do they invest in thermal reading equipment? Why did they buy binoculars, GPS, trackers?
I see some of the arguments as resisting technological progress just for the sake of it, and we must stick to the old nostalgia. Remember a similar discussion on radio DT in the nineties? Still of the opinion this is bad?
If the sheer joy of bad luck is so important to them, then why don’t they drop all the above tools from their tool box and go back to the old Seelig timers or fuse?
Or drop the F1 class altogether and start nostalgia?
If one model flies downwind to a spot 50 meters lower and the other flying upwind 50 meters higher. This is free flight. One flies longer than the other. A time keeper will record this, just like an altimeter will show this. The presence of an altimeter in the fuselage won’t change the flight behaviour of the model.
If a model flies out of sight for a time keeper, this is the bad luck (or ‘joy’ for some) of free flight. This is a however a subjective opinion.
If an altimeter shows the model flew into a 50 meter deep valley and continued flying for a higher scoring out of the time keeper’s sight, this would be just as much good luck und just as much joy of free flight as staying within eye sight of a time keeper. Just another subjective opinion.
The final result will however be objective.

Thermals and good luck to all!

Where was the F1X on the field?

From:Roy Smith

Answer to Giorgio Venuti.  It makes no difference what the topography of the terrain is.  An altimeter records the height above some fixed datum - sometimes Sea Level, but more often from the point of departure.  Even if the models are launched from points of differing altitude the altimeter will determine the height from the point of launch, thus eliminating any such perceived advantage.
Roy Smith


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