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Author Topic: New F1C RDT Rules  (Read 712 times)
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« on: June 03, 2015, 01:53:29 PM »

I don't have a dog in this fight, but I'm wondering how long it will be before a rule like this bleeds over to other classes:

Quote from SCAT Electronic News, dated May 29, 2015


According to Ian Kaynes:

"The current rule reads:

F1C models may use radio control only for irreversible actions to control
dethermalisation of the model. This may include stopping the motor if it is still running. Any
malfunction or unintended operation of these functions is entirely at the risk of the competitor.

And from January 2016 it will be

F1C models must be fitted with functional radio control only for
irreversible actions to control dethermalisation of the model. This may
include stopping the motor if it is still running. Any malfunction or
unintended operation of these functions is entirely at the risk of the

(Bold/underling mine)

So, in 2016 you must have RDT? (There is a big difference between the two words "may" and "must") Yes, the use is optional, but you must have one?

So, now the rules are dictating a minimum amount of technology? I find this to be an interesting development.

"We have done the impossible, and that makes us mighty..."
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« Reply #1 on: June 03, 2015, 09:17:40 PM »

Yes, starting in 2016, having RDT on your F1C is mandatory. But using it isn't. Which is odd to me.
I don't think the rule makes sense as it is. Much discussion which some consensus that using RDT without the ability to shut off the engine in advance may well be less safe than not using it.


F1B guy...
But don't hold that against me!
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« Reply #2 on: June 04, 2015, 12:10:40 AM »

I loved flying F1C way back.
Guess you could say I started in 1955 with a Swiss Miss Elfin 2.5 then Oliver Tiger powered for the second one.
The '70s were sensational days with Rossi's that took me into the '80s.
But after that I stayed mentally in the '70s and '80s with building them on glass, or buying them, and now RC in them.   
Goodbye F1C.
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« Reply #3 on: June 04, 2015, 01:08:06 PM »

I have a vivid memory of the value of the device they want every F1C flier to fit, from Poitou in, I think, 1987.

Double World F1B champ. Lothar Doring was flying F1C with all molded Koster models. I didn't see the launch, so I don't know if it was a bad launch or what, but I saw the model arc over and start heading for the ground very quickly.
A lot of people would be unaware, but Thomas Koster had all electronic timers as far back as 1981, and by 1987 had apparently perfected RDT too. Doring hit the button, killing the engine and activating DT simultaneously. The wing plugged into the pylon with wire joiners, so it pretty much folded in 2, but still stayed attached and together. The resulting DT descent was untidy and pretty fast, but Doring had the wings off, ground off the bent joiners with a handy grinder he happened to have in his field box, put new joiners in and was back in the air within 10 minutes, successfully this time. That was back in the days of 7 secs engine run, and although F1Cs were very fast back then, todays models have  more power up front, and thanks to geared drive, MUCH higher initial acceleration. It will be no small feet to launch a model and react to an impending crash by hitting the RDT button inside 5 secs. Also, if DT and engine stop are activated together the wings will not survive, and the wingless remainder will be a silent, if unstable, javelin.

The mode of failure for the modern F1C is for the tail to go to the BUNT position and drive the model into the deck very quickly upwind of the launch point. A couple of sources have indicated that this happens with disturbing frequency. I haven't seen very much F1C flying in the last 20 years, but I have seen it happen (at Lost Hills) and such an incident features on the very good video on YouTube of the 2009 World Champs. This clearly illustrates the danger CIAM are seeking to address, but there are other, possibly more sensible ways, of course.


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« Reply #4 on: June 04, 2015, 02:27:28 PM »

This will come as heresy to some, but I seriously think it's time to lift the ban on closed loop control for F1C. For $30 you can have an APM that will keep the airplane pointing perfectly straight up throughout the motor run. Way safer than requiring a flyer to equip his airplane with a device that will result in inflight structural failure of the model and probably not make the whole shebang any safer for people on the flight line (not to mention that most don't have the reflexes to get to the RDT in time anyway!)
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Simplicate & add more lightness. Keep sanding!

« Reply #5 on: June 04, 2015, 02:59:12 PM »

GM John, you have hit the F1C nail on the head. 
Why in God's Green Earth would any rules making organization MANDATE an RDT rule which almost certainly will result in destroying
the object or device which they need & are competing with? 
The RESPONSE TIME required (should it be necessary to actuate the 'unsafe' forced landing RDT) to activate within 4 SECOND (or even 5) 
shutoff of motor run, seems near superhuman ability.
As for the 2009 WCh YouTube video incident, I personally was within 20 feet of where that occurred.
As I recall, a gent was hit with luckily only a scratch, bruise or small cut...but it was a near miss from being disaster!
I for one hope this unsafe rules change will be recanted, as the CIAM recognises the actual factors various intelligent people
have notated globally on such forums as this. 
FLAK jackets & helmets will be needed, if not.

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« Reply #6 on: June 04, 2015, 06:44:56 PM »

F1C New Rules
I feel I am imposing , making suggestions related to F1C rules as I am not an active flier at this time in the class.
As for my background, I flew FAI Power (now F1C) from the mid 50’s to the late 70’s, including two World championships for Ireland in the 60’s (using 1.5 cc models).
Although, living in eastern Canada since 1979, where little or no free flight is flown, I have solidly maintained my Free Flight interest and am currently flying electric duration models. I also am active in R/C sailplanes both pure and electric and also Multicopters and Aerial photography.
I have followed the new rules in F1C and am convinced that they will be the demise of the class. The support from the active competitors is non-existent.   Surely these are the people who have the most to benefit from realistic rules.
I have noted that F1b has developed from the early 50’s when 80 gm motors were the norm, through reductions to 50gm, 40 gm and now 30 gm motors. Maybe the same approach in power reduction in F1C would be a realistic solution.
In the late 60’s or early 70’s, there was a movement to reduce motor size from 2.5 cc to 1.5 cc, using the same airframe size as for the 2.5 cc models.  This fell by the wayside, but it is something that may now be worth considering. There is a sad lack of potent 1.5 cc motors, but I feel that with the expertise of motor manufacturers, they could be very quickly developed.
OK, we would have a large number of obsolete 2.5 cc motors resulting, but the transition would be a much less of a cost than discarding current airframes.
The motor technology today would produce 1.5 cc motors with more than comparable performance to 2.5 cc motors of the late 70’s or early 80’s.  A 7 second motor run would be a good place to start.
These proposals would bring F1C to a more realistic competition class without resorting to misguided missiles.
John O’Sullivan

John O'Sullivan
MAAC 5401
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