SEN 1961

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Table of Contents – SEN 1961

  1. Mentor of the year – Nomination.
  2. Rubber etc at the fab Feb
  3. Rules – Buskell -c
  4. Rules – Achterberg- b
  5. Rules – Lenartowicz – a


Nomination Request for 2015 Mentor of the Year Award

At the AmCup Banquet, we award the Mentor of the Year Award. SCAT is requesting nominations for 2015. A simple email with a short description of the nominee’s mentoring free flight activities is all that is needed. Jon Davis started the award in 2005 and provided the stylistic trophy. The trophy is topped with a wonderful brass casting of a youngster launching a model aircraft that Jon had commissioned. Previous winners are shown.
2005 Buzz Averill
2006 George Batiuk
2007 Art Ellis
2008 (not awarded)
2009 Jim Parker
2010 Bob Piserchio
2011 Connie Piserchio
2012 Rocco Ferrario
2013 Jon Davis
2014 Tim Batiuk

Thermals,
SCAT
Jim Parker
<N89015@aol.com>


Rubber etc at Fab Feb

From: Charlie Jones
Hi Roger,
could you please post the following in the next SEN.

“We are still taking order for supplies and rubber to be delivered at the FAB FEB Contests in Lost Hills. The cut off date for ordering rubber to be delivered at these contests has been extended to January 28th. We will not bring extra rubber to sell, so you must place an order with us prior to January 28th. Please contact us via email; sales@faimodelsupply.com
Thank you! ”

Charlie Jones

More thoughts for the FAI Rules/Future Debate;

From: John Buskell
Hi Roger,

A disappointing aspect of the current discussions (and past discussions,
come to that) is that some people feel compelled to throw out insults. The
BMFA is one of the senior model aircraft national bodies in the world, if
not THE senior national body. It’s democratic mechanisms are tried and
tested and respected by all the respective internal delegations, and
specialist bodies. It is extremely unlikely that the recommendations coming
out of the BMFA come from people who are not involved in FAI competition.
To state otherwise just smears the BMFA. These people are saying “I don’t
see it that way, so you can’t know anything.’

It’s inexcusable.

Elsewhere in these discussions somebody stated that the modern F1C can
achieve climb heights of 170m in the allotted 5 second engine run. I don’t
believe that claim was backed up with any data, but it seems a good
estimate to me. In the January 1980 edition of Aeromodeller magazine, in
the report on the 1979 World Champs in the US (at Taft), there is a
statement saying that the highest recorded climb by an F1C was 180m by Doug
Galbreath. This was a wooden F1C of modest aspect ratio by today’s
standards and with an engine producing at least 15% less power than current
engines, but of course the engine run in 1979 was 7 seconds. The 1979 World
Champs was decided at the 6 minute stage. From this we can deduce that
altitude is not the reason for fly-offs going longer and longer in the case
of F1C. As climb height in 1979 is approximately equal to that of today’s
models despite the reduction in engine run, the initial acceleration must
be greater in today’s models. A cut to a 4 sec run will place further
emphasis on acceleration, forcing competitors to opt for geared engines
exclusively, and then all new propeller designs in order to optimize a 4
second climb. This change will cause obsolescence in the single most
expensive component, surely.

I got my head pretty much chopped off a decade or more ago for daring to
suggest that silencers were needed in F1C. Well, I pretty much stick by
what I said, a silencer rule didn’t kill F2D Combat, they just got on with
it. A standard silencer rule doesn’t have to make F1Cs quiet per se, but we
do need to take the edge off the noise (IMO), which is better for everyone
on the field, surely. They could initially be optional, being defined in
the same way as F2D, and if (as people say) they rob power, models so
equipped can have a longer run, incentivizing compliance. My motivation is
purely selfish in this – my local site pretty much demands it, and I don’t
see why the rules should effectively exclude me. It’s clearly not a
slippery slope to tuned pipes. Again, look at F2D.

In 1971 Thomas Koster was 2nd in F1C at the World Champs in Sweden, using
models featuring variable camber wings (i.e. ‘flappers’). It was related at
the time (which makes this anecdotal data), that Mr.Koster had made tests
with his models by towing them up on a 50m line and timing them to the
ground after a gentle, non-bunting or zooming release. He (it was reported)
was disappointed to only achieve about 60 secs in these tests. Clearly it
is reducing sinking speed that is causing longer and longer F1C fly-offs,
and the Brits have correctly identified that increasing Aspect Ratio is the
principal influence in reducing sinking speed. I do not see span (or aspect
ratio) limits as creating compulsory nostalgia models. You still have full
access to structural development, airfoil development, prop. and engine
development. Is it really any different to the wheelbase or wing
restrictions in Formula One? Nobody would call a Formula One car a
throw-back to a by-gone era, would they?

Your choice to publish, of course Roger!

best regards

John Buskell

Thoughts on Rules
Rules. Well, where to start. My first F1b model was a A1 glider wing that had Hank Coles airfoil on it. It was too light and not strong enough, so decided to make a F1b out of it. Now I don’t know a thing about F1b. Still don’t. But bought a Starline non DRP frontend. Had to hold the prop to launch, but hit my hand on start a couple times and broke blades. I was also flying very short motors with a 22 second motor runs. Very fast and fun to fly. I was a power flyer, so Need for Speed.. But decided that I want to get my hand out of the way, so I would stop hitting it. Simple fix. I bent a little wire hook that held the right blade out and held the tip of left blade. Leaned back while holding tip of left blade and threw it very hard. Simple fix , an instant start without a DPR frontend. this was in 1992. Now, way back then the DPR was used by most flyers and still remember seeing Alex reaching back and throwing model up about 15 plus feet. Very impressive. Then the model came to a stop and prop started and on its way. looked awesome. Problem was the stop and then model taking off. I wondered if this was an actual gain of 15 feet. Yes it was if compared to a VTO. But the energy used to start the model up from a dead stopproved to be not the gain in altitude it appeared to be. Professor Dave Lacy from Univ. of Virginia did some calculations for us. I think that was where he taught. Long time ago, and Im braindead now. but the results worked out like this. A flyer would have to throw a model straight up at 35 mph for a one second delay to actually be a overall altitude gain verses an instant start. Simple, it proved all for show, and instant start proved to produce over all altitude gain for energy use. Maybe a professional baseball pitcher might be able to throw a model at 35 mph straight up, but it was probably not possible. Certainly no flyer could do this. In conclusion the DPR only adds very little unless they make us hold both props. If not, I will just use my little Z hook to hold right blade out on launch. And once DPR band everyone will just add my little wire hook and fly pretty much as they do now. Now, as to 25 gr motors. Of course we can do it. Question is why????? to keep model on small field?? Whether 30 or 25 gr its the thermals and wind that makes field size the problem. We have had contests and test fly sessions that a 7, 8, 9 minute flight land at our feet or close to it. So yes, a model that gets higher goes further. No doubt!! But whether you get 70 m or 110 m after motor quits and in any wind or thermal or combo of both the model will travel along way. Its freeflight. !!!! Simple small field fix. Cut down the max time. Or don’t hold Big FAI contests on small fields.What is being proposed is to make F1 models that you can fly at the local park. Wow, now that will be fun. Hard to imagine that many will keep flying with proposed rule changes. Is 25gr a killer to the event. Probably not, but certainly will not level the playing field. The experts will excel with this. It will be harder for the novice flyers like myself, that aren’t too good at this. We fly cause it fun and models are easy to fly and sometimes we get high and Say Wow!! but models will be little fun for me at 25 gr. The power to weight, to area ratio would be less than Coupe. No WOW factor. For me not interested. But coupe will now be the faster model. Think about coupes in the wind. Now factor a bigger slower, less power coupe, F1b, in the wind. Boy, that will be fun.. Anyway, make your rule changes well thought out before you kill a really fun event to fly.Thermals or Not!!..

Michael Achterberg

More on FF Rule Changes (and tow line length reduction concerns)

As a final though on some of my earlier comments on this issue, and in reading some of the proposals and plans passed along to us by Ian Kaynes, it seems that the ideal solution would be to simply move the clock back 10-15 years. This would not be entirely inconsistent with my proposal to simply revert to two sub categories within each Free Flight Class in the short term – a classic and a high tech. The classic would be a traditional class without any of the advanced modern technologies of the last decade, with the high tech variant essentially the current version we have today. Over time, it is likely that the easier and cheaper access to the classic version of competition would move most competitors to that category anyway, and if high tech elements remain an over- performance issue, then the high tech subcategory can be eliminated at that time. However, to make changes that would require everyone to discard all models in 5 years by making fundamental changes to model parameters (wingspan, etc) and have everyone start from scratch on all elements seems like a particularly extreme solution.

The sport today is very expensive and complicated. However, there is also a group that enjoys the high tech models today, and there does not appear to be a lack of interest from those hosting the contests (to some extent, they need to have some responsibility to accommodate the changing requirements). Granted, there are issues with over-performance, but this is not the cases in all contests on a regular basis. It is important to remember that the observation of performance at European or World Championships consists of the best flyers with the best models, so the problem would be most visible at those events. This is certainly less of an issue in more local contests. Having a classic sub-category in place in the near term would also move to resolve this issue. The “classic” version would likely achieve performances that were achieved 10-15 years ago – essentially topping out in the 5-7 minute range, as opposed to the 7-10 we are seeing now, and move competitors back to a preferable balance between field capacity and model performance.

I also wanted to comment specifically on the shocking proposal by Poland/Austria to reduce the tow-line length to 40m or even 35m, as this affects me personally in F1A. I would be curious to see the innovator of this suggestion try to tow a model at this length of line in 8-9m/s winds. I know, as do others, that even under 50m you need the extra 10m to circle and avoid grounding, which isn’t always easy. Unless the thought was that it would be a straight launch without any towing? Additionally, while the reduction in towline length to 40m may reduce the numbers making it to the flyoff, it is not going to do much to affect the problem of extreme performance ( if a model finds a thermal to make an 10 minute flight, it’s still going to find that thermal and still fly about 10 minutes). The reduced towline, however, will have a very negative effect on towing performance and participant/model safety.

So in summary:
– introduce a “classic” subcategory within each Free Flight class, that would place limits on advanced technologies, while allowing an “open” subcategory for high tech models. Maintain a separate set of scoring for each.
– over time, with an alternative available, the trend should be towards more participants moving to the “classic” format. At that later date, and depending on participation numbers, we can consider phasing out the “open” category, but it’s too early to do that now because people have too much invested in it.
– do NOT redesign free flight from scratch: we’ve flown to the same model and flight parameters for decades, no need to scrap everything (i.e. fundamentals), we only need to change what is not working (and be more careful in the future about the consequences of any changes we introduce)

Chris Lenartowicz
F1A – Canada

USA Team Final’s management caveats

1_What are we testing at the finals?

Regular rounds at the finals have one flier per pole with a 25 minute window. Ignoring F1A in which piggybacking is difficult, in B and C one observes mass launches if someone happens to have launched into good air. In other words, with one flier per pole we are really testing the piggybacks skills of most B and C fliers. Indeed, in the last finals, the only time each flier had to choose when to launch was during the 2:30 rounds when the wind was howling.

IF we really want to test the B and C fliers’ ability to choose thermals, we should assign two fliers per pole! Admit that it sound like a bitter medicine. Suppose two B fliers on a pole are being timed by an A flier. The B fliers would have 40 minutes to fly each round, divided into 10 minute time slots. On day 1 half the B fliers would be randomly assigned to the first and third time slots, the others to the second and fourth slots. (The next flying day positions would be switched.) Once one of the fliers on a pole flew, the other flier gets the rest of the flying time. During the following 20 minutes C will be flown. This schema can work for C (two fliers per pole) being timed by B fliers but will not work when B and C are being timed by A fliers as each round would expand to 80 minutes. So when B and C are flown in the same day, C would fly with one flier per pole. (Sounds like a ¾ solution.)

Of course fliers can still piggyback in a two fliers per pole setup, particularly during in the first and second time slots each round. But the number of fliers on the line is at least halved and those who fly in the third and fourth time slots would probably have to pick their own air. Furthermore, the suggested two fliers per pole better replicates the way a World Championship is run.

2_When to start an effective flyoff?

Typically finals start flyoffs at pre-assigned times. Any delay in beginning the early morning flyoff will impact the rest of the flying that day and increases the chances of thermals. But afternoon flyoffs an actual delay might be beneficial if the conditions get worst and more fliers actually drop. In other words, flyoffs when a large thermal is passing just wastes time.

One should therefore attempt to start an evening flyoff in reasonably bad weather conditions. Suppose an evening flyoff is scheduled for 4:00 PM. A minute before the flyoff is supposed to begin the CD could judge the conditions as being “too good” and delay the flyoff by 5 minutes. And just before the delayed flyoff is supposed to commence the CD can decide again to postpone it by another 5 minutes etc. Weather conditions change over time and the flyoff is bound to start after 3 or 4 delays. Once the flyoff begins conditions might change – either improve, stay poor or get worse but starting in poor conditions will most likely reduce the number that max.

Since choosing bad air is a critical ingredient, the advice from a few experienced fliers might be very helpful. A clueless CD would probably choose the best conditions to start a flyoff getting the worst result (a maxout).

Actually, delayable evening flyoffs might be useful in any contest.

Aram

………………..
Roger Morrell