F5K Multitask Electric Thermal Duration

F5K is officially on the way and this new contest format blends multitask events like F3K with electric powered planes.


New Contest Format for 2020

F5K is officially on the way and this new contest format blends multitask events like F3K with electric powered planes. I think one benefit here for pilots with low DLG launches is that it will even out the playing field to focus more on air reading and flying.

The planes used are to be 1.5M with an electric motor and an altitude limiting device like the Altis Nano. Max weight is 600g and max battery size is 3S. So what do you guys think? Is this going to be popular in the US and bring more pilots over to the soaring side? I'm certainly interested so it will be fun to see how this grows. I'd love to hear your thoughts on this new format.

Check out the FAI F5K CIAM Format Info Here

Thread Tools
Dec 03, 2019, 10:00 AM
dnbarrie11's Avatar


Where does this event fit in? Most people can't serve all the competition gods. Currently popular in the soaring world, F3Res, F5J, F3K and TD/F3J is still hanging on. So now we add another speciality event with specialized aircraft. When/where will events be held? It becomes a situation where competitors will have to choose what to attend. This will result in spreading out the competitors and reduced attendance at most.

Just my thoughts.

Darwin N. Barrie
Chandler, AZ
Team Futaba
Dec 03, 2019, 11:03 AM
eteet's Avatar
Originally Posted by dnbarrie11
This will result in spreading out the competitors and reduced attendance at most.
This has happened in other facets of RC competition. Eventually each event will only have a few entrants.

Dec 03, 2019, 11:32 AM
sneu's Avatar
It is not on the way---it was just proposed and will get discussed at the April FAI meeting in Lausanne and likely there will be changes based on some early comments from those on the F5 committee. If it survives then it could become a provisional class. As proposed the rules have lots of problems---not the least of which is they are difficult to even understand. F3K is a hand launch duration orientated event---not "multitask". Multitask events encompass duration, distance and speed in some combination.
Steve Neu
Dec 03, 2019, 11:46 AM
Registered User
How does this differ, other than the span, from the TALES event format?

Dave R.
Dec 03, 2019, 12:20 PM
Registered User
Event dilution is inevitable as the sport evolves-F3J for example. The biggest challenge for 2020 IMHO is the 400' limit. For current 4m planes this is just a killer. Somewhere-sometime someone is going to be caught and the legal fur will fly. This has been beat to death-for this discussion lets assume the 400' limit will be enforced.
F3RES doesn't interest me (performance and high start) so in the 1.5m size I see this as a viable alternative for old guys that cant throw any more but still want performance-not to mention eye site. This format emphasizes air reading-like F5J without the range.
Its also wide open to design ideas. The only planes ive seen are converted F3K, but there are other options. Look at E35 free flight designs.
My point is if we are restricted to 400' this seems like a good alternative. Wish it was not the case.....
Dec 03, 2019, 12:32 PM
Dark Side of the Red Merle
Curtis Suter's Avatar
Originally Posted by dreisinger
How does this differ, other than the span, from the TALES event format?

Dave R.
Europe vs the USA?
Dec 03, 2019, 02:08 PM
Registered User
Firstly I think there is room for another multi-task F5 class that is not like B. 3K is a good model for the rules but 3K tasks don't perfectly lend themselves to electric power. I think it could be a cool class although I do fear the vast majority of pilots will be from 3K.

Lots of people arguing over dilution of classes, but competition classes shouldn't remain static. For example F5J??? Also guys on the F5 committee are looking to INCLUDE more pilots. Do all pilots that want a multitask event want to fly "B"? Do we have equivalent models to 3K? Dilution of course is a concern but I don't understand how that is any kind of a reason not to have a class. Again F5J is a perfect example.

Secondly I don't think the 400' discussion belongs here. Plenty of other threads specific to this topic.
Dec 03, 2019, 04:10 PM
Registered User
John O'Sullivan's Avatar
When the going gets tough and everyone is in confusion, it is time to introduce another flying class with enough complexity to deter even more potential fliers.
The FAI in particular are big offenders in the "COMPLEXIFICATION" of contest rules. They have "Electronified " even the simplest of contest categories to the extent that the modelling factor is now almost non existant.
I fly mostly low key RC sailplanes ranging from own designed F3S models to 4m full house Pulsars, but with the sparse numbers of fliers in Nova Scotia no longer fly competitive events.
I also am active in Free flight classes and have had many published designs. I also enjoy indoor RC during winter months.

The most significant "shots in the arm" in model flying in recent years have been the development of the F3RES RC sailplane class and the Free Flight E 36 (adopted by FAI as F1S) electric duration class. Both of these classes have simple rules without emphasis on elaborate and expensive models.
These Classes have seen growing numbers of fliers participating and competing without getting wound up in complex "electrickery". I have had a renewed interest and have designed some new models in both classes. My E 36 Blizzard was published in NFFS Magazine and has won several European contests and is kitted by Hummingbird.
We are fortunate in Canada to have successfully negotiated with Transport Canada to get recognition of MAAC and getting exemption from very restrictive regulations, while flying under MAAC safety regulations. So far this has worked extremely well for all parties. Hopefully the FAA will wake up and give similar exemptions to legitimate AMA members.
Last edited by John O'Sullivan; Dec 03, 2019 at 04:23 PM.
Dec 04, 2019, 12:16 AM
In F3J size does matter!
roydor's Avatar
The FAI is only an organizing body. Rules, new classes, complications and measuring devices are all hatched up, brain stormed and conspired by people like you and me who want to fly. The only difference is those regular folks with the new ideas have a vision and are not afraid to approach the FAI to bring that vision to life.

Now, if a group of people came together and thought up a new class, don’t be so quick to condemn, there was a need and desire behind it so it has a place.
The idea for F5K came from F3K pilots who aren’t capable of throwing competitively anymore but love the format of F3K. F5J is a nice class but has a single soaring task and to be honest, has models which are over performing and expensive but that ship has sailed (I don’t see a rule changes for higher wing loading and shorter spans anytime soon...).
Don’t get me wrong, I enjoy F5J a lot but see how F3K is much more approachable and how it attracts people looking for a little more excitement.
As the rules are now, I agree they are a bit too complicated but I expect that will change quickly.
I hope to have some free time soon to electrify one of my F3K models to try it out.
Dec 04, 2019, 01:28 AM
Registered User
MikeC's Avatar
If it was a two meter event using F3K technology, I would be interested.

Dec 04, 2019, 03:42 AM
In F3J size does matter!
roydor's Avatar
Originally Posted by MikeC
If it was a two meter event using F3K technology, I would be interested.

Trying to introduce F3K task “genetics” into F5K suggests starting with F3K planes as the start point.
I personally don’t see a reason why it has to be 1.5 meters, perhaps in the future it can be made bigger but in my view it needs to keep the performance low enough to make it a challenging soaring task.

One of the things discussed is the minimum weight and wing loading. F3K doesn’t have min weight or wing loading restrictions. F5J has 12 grams per square decimeter as min wing loading restriction. F5K at the moment has adopted the 12 g/sqdm restriction which combined with launch penalty allows for more challenging flying as models will be heavier than most modern F3K models (most are 10-11). I assume that older designs which were heavier would work a bit better than the newer designs as a result. But the happy thing is that building a model won’t be too difficult as you don’t need a super light build to increase performance, a modern DLG is 230-240 grams for a normal layup models, remove the battery at 15g and you have about 50 gram allowance for a 60-70 watt power system which shouldn’t be too hard.
Dec 04, 2019, 11:58 AM
Registered User
There are a lot of F3K models out there.
If the manufacturers offer a electric fuselage like the F3B, F and J manufacturers for existing F3K wings, it will be a class that a lot of people will be interested in.
Dec 04, 2019, 12:21 PM
OK here is what I know and it may answer some of the discussion items here:

....The Greater Detroit Soaring and Hiking Society invented TALES four + years ago and have flown it in four or five club contests each year and modified the rules based upon the last years competitions.

.... The Fx rules took a lot of our first rules set and made them FAI like instead of AMA like (read, more complex) even though our TALES rules are very much like F3K for a reason. Our original rules were a mashup of ALES and F3K because our club members fly both but were almost two distinct groups of flyers and not a lot of cross breading was taking place. One of the main reasons is the club has a lot of older flyers as well as a group of younger (not young) flyers that were good at launching. Some of the older guys wanted to do DLG but it was kind of deflating to launch against pilots that could double your launch height. We discussed it a lot at one of our annual holiday parties (also has a business meeting attached) and decided that wing loading etc would favor 80 inch planes rather than F3K planes. This along with being able to see an 80 inch plane further out made the decision to go this way. The couple of converted DLG planes tried later proved to be lacking.

The results have been great for TALES as this year it had more competitors in our Club Championship than either ALES//F5J or F3K because of the now present cross over of competitors. Both groups are really liking the format and that is after a lot of contests and a lot of work to satisfy both groups. If you or your club have never flown F3K then there is a learning curve and some overhead in timing over ALES but none of it is difficult and after a couple of contests you will know what to do so do not let that deter you.

..... We (GDSHS) tried to do a demo at last years NATS but for several reasons it did not have much participation and most of the flyers were gone by then. Those that stayed and participated said that it was interesting and should be pushed further. We will be working with LSF to see if we can get a full day of competition in the next year or two at the NATS. In the meantime we would love to see other clubs try it out and comment on it the next season. If we can get some support the LSF will cooperate.

... Although F3RES is seeing somewhat of a bump and we have two members that do it, it is impossible to fly it at our field as high starts are out. TALES only requires a small area to handle the launch and landing tasks so can be flown almost anywhere you would fly electric sailplanes.

.... Soaring Circuits (CAM altitude switches) have been making TALES switches (60/80/100M and 20 sec) for a couple of years for us on special orders and they are the easiest ones to use in the competition as no readout is necessary and can be programmed without computers or cards.

.... The scoring program for the TALES is on Curtis Suters website at www.Tailwindgliders.com and Curtis has kept up with all the changes to the rules for us and we owe him a couple of beers for sure.

.... The rules for 2020 are on our web site https://www.gdshs.org/tales_rules.html

So we think our event is more of a fit to the way we in the AMA world fly than in the FAI world as it is suited for club work as well as more major contest work and the planes fit this kind of event better than the converted DLG ships.

Enough for now but if you have questions or need more information, please let me know and I will try to answer them.
Dec 04, 2019, 08:58 PM
Registered User
scirocco's Avatar
I understand the desire of F3K fliers who can no longer launch competitively to fly the same rather exquisite type of model in an electric launch format, but I think the TALES format allowing 80" models has the potential to increase participation big time. It makes a Radian for example an entry level and requires far less finicky fragile equipment. And I suspect a good but launch challenged ex-F3K flier, ie the sort of person wanting to leverage their investment in 1.5m models, would make many 2m pilots look very average.

Interesting that the thread title has already changed to include F5K. Is TALES seen as just a subset of ALES, or does it deserve a run also?

Quick Reply

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Article My First Thermal Duration Contest Jason Cole Multi Task F3X 19 Jul 01, 2018 11:17 AM
Discussion Question: How are your local thermal duration contests organized and scored? Miami Mike Sailplane Talk 16 Jan 30, 2018 05:56 PM
Contest Hybrid Contest....Mixed Launch Thermal Duration bitzerj Electric Competition Soaring-F5J/F5K/ALES/E-Soaring 2 Apr 08, 2016 09:10 AM
Competition Hybrid Contest....Mixed Launch Thermal Duration bitzerj RC Flight Events 0 Apr 05, 2016 09:04 AM
Question Thermal Duration wing and airfoil flying plank hog2soar Nurflügel 7 Dec 05, 2015 01:05 PM