SEN 2193

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Table of Contents – SEN 2193

  1. Timing and performance -2 two separate questions but related
  2. On altimetry time keeping.
  3. FAI Classes participation
  4. The Logical Conclusion ?
  5. The SCAT family at Stonehenge
  6. Editorial Comment on auto-timing


Timing and performance -2 two separate questions but related

From: Alan Jack

On timing
In my view there can be no objection to automated timing provided it is accurate and inexpensive. In my experience altimeters suffer markedly from venturi effects and have significant “noise” so I worry that the flight which hangs on very low will be accurately timed within the 1 sec we are looking for.

On performance
We are living in fast changing times with decreasing tolerance of flying out of the field, increasing litigation on safety infringments, increasing requirements placed on event organisers to have an effective risk assessment plan and of course FPV plus programmed GPS which technically allows models to be flown well outside visual range. As far as I am aware legislation is based on keeping models within unaided line of sight. In the UK we are keenly aware that we must act to try to keep models within the field. If a contest director deliberately acts so that models do fly off the field and cause an accident I don’t see how they can avoid the legal consequences. This is just as I stated when I wrote to SEN last year. It’s not something which is unique to the UK. I have three times flown over Holloway Road at Lost Hills on each occasion it was a normal flight. The last was in an F1C flyoff and I finished a lowly 6th or so. I landed just over the oil production site – plenty of chances to cause a spectacular accident in there!

So in my view we must act to reduce performance. The issue is not rounds flights of 3 mins or less, it’s the flyoffs. Currently we need a flyoff max of at least 9 mins to settle a high level contest on a good site without any thermal assistance. That’s a huge site requirement even in light winds.

Really we need to restrict still air performance to more like 4 mins.

This is the background to my major worry on automated timing. As David Ackery said so accurately it encourages the idea that it is acceptable for the model to go out of sight ( which breaks legislation?) and off the field (which us increasingly unacceptable).

Alan Jack

On altimetry time keeping.

As author of the proposal it is very interesting and sometimes entertaining to see the arguments both pro and con.

However I can not help to conclude that some of the authors did not read the proposal as written in the last symposium report. If they would, things would become somewhat clearer.

For instance, landing in a tree or on top of a corn field will not increase the registered time to secure a win. A flight is only considered ended when a rate of descent as shown in the graph will suddenly change to a zero rate of descent.

If the graph does not show such an ‘event’, it will be inconclusive and the time as registered by the time keeper will prevail.

Altitude recording resolution must be at least twice per second. There is a good reason. If a lower resolution is used, a change in rate of descent is more difficult to establish. Since flight scores are recorded in seconds and not in units of 5 or 10 seconds, a resolution finer than 1 second is required. Most commercial stand alone altimeters have this feature.

The purpose of altimetry is definitely not to allow a contest organizer to stretch flight times to go beyond field boundaries. This is a totally different discussion. Use of altimetry is to reduce time keeping error in fly offs, not for other reasons. Once again, altimetry is not mandatory and will only be used if a sportsman disagrees with the score as entered by the time keeper. In practice I expect that only few disputes will be filed, e.g. if a time keeper timed the wrong model or got a fly up a nostril. There is no use filing a dispute if you know the time keeper did the right thing, as the altimeter graph will show the same time as the time keeper’s. However, it will give very interesting additional information, as result lists will be so much more dynamic.

Allard

FAI Classes participation
From: Richard Wegener

Hello Roger
I’ve been following the discussion of how to increase participation in the FAI events.
I would like to add a few comments.

First, a brief introduction: I grew up flying Freeflight in Southern California. Spent much of my time at Taft, Lake Elsinore and even “The Basin”. I learned most of what I know from Sal Taibi. Now, I am probably what you would call a “re-entry” modeler. I am now living in the Northeast, and fly with SAM7 and The Brooklyn Skyscrapers. I have, in the past, dabbled in F1B. I was never too successful with the class. Now, when I go to a contest, I mostly will pay the entry fee, and then never post an official flight. I believe in supporting the ‘hobby’ and the host club, but I really don’t give a darn about competing.

I am a electric covert now, and almost everything I fly are electrics now.

Instead of trying to offer any kind of solution, I will simply tell you why I don’t really participate in the FAI classes. This is only my own personal opinion. It is, in no way, representative of anyone else.

I agree 100% with something Bernard said: “When a business wishes to expand sales, it doesn’t survey those who are
already customers…”

So, you may ask, if I am not interested in competing, why am I  “here”?

I love Freeflight because, and this is very important to understand, is that I love the design, fabrication and test flying of the airplanes, in that order. It is extremely gratifying to me to see a design (my own or an existing design that has “caught my eye”) go from a concept, then rise from my building board, like a Phoenix, from a 2 dimensional piece of paper to a 3 dimensional object. Then to take that object out to a field and breath life into it. Seeing something that I created soaring above me is a joy.

Now, once I have built and trimmed out an airplane, if there is an event that it might qualify for, I might enter it. But, competing in an event is way down the list of why I fly.

As you may correctly guess, I will not, under any circumstance, ever buy an airplane. Buying an airplane is completely contrary to the reasons stated above.

So, is there anything that would entice me to participate (seriously, that is) in FAI events? Well, not that I can see. As the airplanes and rules become more and more complex, and the only way to be competitive is to buy an airplane, the further it gets from my participation.

There are, actually, two things that I can “gripe” about, specific to contests. And these two things are a big reason that I often don’t post officials:

1)      Timers. At almost every contest I’ve been to during the past couple years (including the Nats this past summer), it has been a pain in the butt trying to find someone to time a flight. I do not have a “buddy” to work with, and when it comes time to post a flight, it becomes very obvious that asking someone to time a flight is a major inconvenience.

2)      The 5 second motor run. As I said, I build and fly airplanes that I like. Most times, this means airplanes that were designed for much longer motor runs. Most of my airplanes do pretty well at 10 seconds, but 5 is a killer.

So, as I said, I offer no solutions, only my own thoughts.

Rich Wegener
West Hartford, CT

The Logical Conclusion ?
From: chris edge
Nurse SCAT,

Duke Guest rightly asks “why in gods name are you using these things to time your airplanes?; you have heard of technology right?”

Yes, to do it properly and accurately we should be using telemetry transmitting directly back to a secure server that monitors all models continuously and provides accurate timing – job done. The systems exist and they could simply become a prerequisite if we wanted.

But let’s go further as we’re having a discussion and look at the classes we have; how do they stack up to modern technology ? The most obvious anomoly is F1B – what other form of transport uses rubber ! We should kill the class immediately as the technology argument simply doesn’t stack up. Similarly F1C: using carbon emitting fossil fuel internal combustion when we should be using green energy (well electricity anyway) – kill, kill, KILL ! Gliders are a throw back as well, ban them. F1E – enough said.

So that leaves Q. An obvious technology based class using modern materials, a green power source and some cute electronics; ripe for development if we follow a logical technology path. Clearly Aram (or was it Trever Grey ?) had it right all along.

EoB

PS I thought Bernard was much younger than 44 ………….


The SCAT family at Stonehenge

As EoB reported above we went to Stonehenge. The weather was very nice on the days before and after the events but on the days was a little windy.  In the interests of plausible denaiability I did not look at my wind meter.  We both had planned to fly but when LadyS was blown over upon exit from the car she decided  that Lord S could have all the fun.

I think that LadyS wished we had one of those timing Gizmos because on one 2 minute flight she lost sight of the Magic Airplane gong down wind at 30 mph  and clocked Lord S off at under a minute.  The airplane was found  over a mile down wind.  Distance courtesy of Fitbit.

By one of Murphys quirks on the last Stonehenge round the same Magic model did not go straight down wind but was attracted by the magnetic properties of trees and end upon the top a tree in a little plantation.  I found where it was but could not see the model. I had signal with no antenna.  I went back to get help and a bunch or people came to help.
Special thanks to Peter Tribe who spotted the model, clearly Pete had has more practice than me.  Then Richard Jack, distaining the collection of poles climbed the tree, pulled the model apart and got it down. There was some damage on the model. LadyS’s observation was that Richard is nor as young or as light as he thinks he is.  Any way the help from Peter and Richard plus the entourage was most appreciated

The next day started off better with clean scores but on round 3 the wind whipped my model around after the flight knocking off the fin.  I decided to stop at that point as I needed my remaining models for the Sierra and Kotuku Cups this weekend.

Brexit or not the team from France did the best taking much of the podium spots in A and B.  I thought that young Jocelyn Pouzet did very well to make the podium in the Stonehenge beating such luminaries and Findahl, Williams, Carter, etc.  The seniors in the French team took his prize award bottles of Stonehenge Beer leaving him with the kids candy.

I did notice a “new  young ” team running the events of Peter Martin and Richard Jack assisted by Martin Dilly and Martin Gregeorie with advice from Ken Faux. They did a great job in the trying conditions.

So while the results were not where we wanted we did have a great time seeing many old friends.


Editorial Comment on auto-timing 

EoB, my preference is the same as yours, namely to have a “cleverer” onboard device that captures the time and radios it back.

At SCAT we started a project with Favioinics that is kind of half way between. Rene @ Favionics believed that they had the experience to accurately determine the end of flight based on their experience with the FX series. We drew up a proposal for parallel pilot test. Favionics would produce a device that recorded the time in a tamper proof fashion. the contest organizer would read it with USB port on a PC or MAC.

The device could also be put in a test mode where the flyer could use it just like an altimeter. We planned to crowd fund it with the club and test it a a couple of major events.  Unfortunately both SCAT and Favioinics got side tracked by a number of items. I think this was about the time that Val @ Favionics produced twins.

With something like this it is close to impossible to get it right the first time as unexpected issues will come up. Not all of these are technical.
For example the distraction from solving ‘real’/other problems as raised by David Ackery and endorsed by Alan Jack. And the “just help me” as felt by LadyS and mentioned by Richard Wegener in another article.

This is why I think we should do what Allard is proposing and why I supported the abandoned SCAT/Favionics project

I was interested to see the results Allard’s elevator test on FB and Alan Jack’s comment on the venturi effect with pressure based altimeters.  While working on an altimeter in my 7th floor apartment in Wellington, NZ I thought this would be great I can check performance in the lift.

I got some very funny results and did a google search on pressure inside building when there is 40+mph wind outside. Also  comments on how the elevator shaft is is connected to the outside.  Clearly Allard had a more ideal test environment than I did.  Maybe I need to lower my test rig on a string over the balcony ?

… and EoB , Bernard is like all of us , very young at heart!

……………..
Roger Morrell