SEN 3362

1. RCDT in FF Competitions
2. More on BVLOS
3. Janne’s fly-off flight revisited
4. Explanation  on  What did About Time say to Janne Isotalo?

 

RCDT in FF Competitions 
From: chris edge

I respond to Roy Smith’s letter in SEN 3361 regarding his musing on if it should be required that RCDT be used in cases of models going OOS.

In the UK and Scotland we have been operating under a rule covering just this eventuality from the beginning of this year. The rule, slightly summarised and edited for clarity is given below :-

1) Any outdoor model weighing over 250grams shall be equipped with an operating system capable of terminating gliding flight via remote operation by the remote pilot (known as Radio Controlled DT – RCDT) if they are being flown within a competition.

2) Activation of the model’s RCDT by the remote pilot shall be executed when safe to do so and/or before the model is lost from visual line of sight (VLOS).

3) If in the opinion of the Contest Director no viable RCDT is fitted to an appropriate model, and/or no attempt was made to DT before flying beyond VLOS, then the score shall be voided.

The key things to note are :-

a) Rule is mandated for all contest flown models greater than 250grms.
b) Operation of RCDT is a necessity and by inference can be checked by the Contest Director or timekeeper for compliance.
c) If asked to demonstrate and it doesn’t work, of if you don’t operate before loss of VLOS then you get a zero.
d) RCDT can be activated at any time but importantly when safe to do so and, importantly, before loss from visual line of sight.

In parallel our national body (BMFA) asked manufacturers of RCDT kit to consider if they could provide simple systems at an affordable price for new users to purchase. This has lead to new products hitting the market less than the cost of a trio of Welsummers*

*a chicken of high standing, M’Lud.

I have been using RCDT since 2001 or so and have, if appropriate, RCDT’d a model at point of loss from VLOS as frankly it’s the sensible thing to do. Perhaps other countries should consider a similar rule ?

EoB (but still within VLOS)
Editor’s Comments

EoB we are happy that your Domain of  Beyond is still visible.

An observation from a friend who is a Free Flight Scale dude in NZ thinking of coming to fly in the Brit Nats is that following this file he would need to put an RDT in his scale model !

More on BVLOS
From: Chuck Etherington

Some comments in reference to Roy Smith’s SEN 3361 entry
–
As mentioned, limiting performance is a key factor in keeping models within visual line of sight. I agree that aspect ratio would be an elegant way to do that. Not only would performance be reduced, but there would be less dependence on carbon, exotic construction methods, and cost.

The problem is that rule making bodies are faced with balancing the regulation of performance with minimizing changes or obsoleting existing models. Hindsight is 20/20 and putting limits on aspect ratios (9:1 in Roy’s example) would have worked nicely prior to ratios going way beyond that. It’s like trying to close the barn door after the cows got out. Could existing models be retained by being refitted with shorter wings? Maybe in some cases. Would the FF community (especially FAI) rise up en masse with torches and pitch forks? Yes. Would some flyers quit? Yes.

Given enough foresight, performance limiting measures work well for future development. Very difficult for existing models. Would limiting aspect ratio be more palatable if the effective date was pushed out two or three cycles so that flyers and manufacturers had more time to plan for it? It’s conceivable.

Chuck Etherington

Janne’s fly-off flight revisited 

From: Tapio Linkosalo

This Championships was the first that I used the Neurone, and I must say I’m impressed. I can see that checking the flight times from logs is the future.

About Janne’s flight, I was there following things closely. The issue that he raised is that the Neurone logs the flights in two places, as a continuous log and each flight separately. In the latter the algorithm automatically calculates the flight duration by determining the start and end of the flight itself. For the continuous log you need to tap the start and end yourself. Here is the slight problem, as the tags on the screen are quite large, and cover some of the altitude graph, so it is hard to place them real accurately without zooming into the graph.

Janne showed his continuous log, as that is the one that the rules request (you need to identify the logger and show the timekeepers that the log is empty). Next year the problem will go away, as the new rules change also allow the use of logs that contain timestamps without clearing the log, which means that you can then use the flight log of Neurone without the need to clear the log, and utilize the automated calculation of the flight time. In Janne’s case that was the difference, the official time from continuous log was 3 seconds shorter than the one calculated by the algorithm in the normal logged flight.

Another issue that raised during the F1B flyoff was the retrieving time. The rules allow 45 minutes, while the competition manager (or jury) increased that to 1 hour. As it seemed that our retrieval turned complicated (difficult terrain downwind), the competition manager allowed us 10 more minutes. When that time was elapsed we had to request a bit more (“see those headlights, that is them, please wait one more minute and we get the logger to be seen”). As loggers will be more and more used in verifying time in the future, I think the time allowed for retrieve the models should be more flexible. In easy conditions, as were most flights in the champs, 45 minutes will be quite sufficient, but for that F1B flyoff, double that was needed.

-Tapio-

Explanation  on  What did About Time say to Janne Isotalo? 

From:    Frederic Aberlenc

There is 2 ways to read the altimeter graph of MiniNeurone: automatic or continuous

The automatic mode is used in the “last flight”. It detects automatically the landing point. We have developed an algorithm filtering the oscillation and it detects well the landing time.

For continuous mode, we follow strictly the FAI rules and you have to search manually the starting time and the landing time. Who made that? Is it you Janne or the organiser? Anyway it is not easy manually for the landing time because of oscillation and because the graph is very flat.

To be honest, when looking at the graph, 456 or 459 are possible.

In pratice nobody use continueous because it requires to start the mode before the flight.

Best regards

Frederic
editor’s Comment
Also if you are looking at the graph on a phone the screen is small and hard to read that accurately

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Roger Morrell