National Free Flight Society

SEN 2679

  1. Fab Feb Day’s Inn Special
  2. Lost Hills Wheels
  3. Closed loop control
  4. More Looping
  5. F1A for sale

Fab Feb Day’s Inn Special
From: Days Inn at Lost Hills

Hope all is well. We are offering a 69.99 + tax for 1 bed and 89.99 + tax for a 2 bedroom. Use code FEBMACOMP2020 for this discount when calling to book over the phone WITH HOTEL DIRECTLY ONLY.

Days Inn Lost Hills

Lost Hills Wheels
There are 2 companis that have provided chase transport help at Lost Hills

For motor bike repairs (and possibly rentals)
The Motorcycle is  Ryan Copeland and can be contacted   through Facebook at
Arliss TrailersportsCa.

The Golf carts come from All Carts in Bakersfield.  They are in Bakersfield and are also on Facebook and at

1636 S Union Ave
Bakersfield, California 93307

Phone (661) 836-9800

Note that you need to   contact Ryan or All carts yourself.  The event organizers cannot do your arrangements for you.

Closed Loop Controls on the Hill

From:Klaus Salzer

Actually, there IS a free flight class with “closed loop control” : F1E!
the magnet (or electronic system) is set to a specific direction, and if the plane tries to fly in a different one it will steer back. This, of course, is specifically allowed.
What would not be allowed would be to use the diversion of one of the other axes (horizontal and longitudinal), which on modern electronic systems are “byproducts” of these systems, ; for control purposes. The only way to really prohibit this would be to ban any direct control of the stab when electronic directional control is part of the model, like the stab control systems used by F1A. Only “irreversible” actuators (like releasin trip wires) would be an unquestionable solution.
Actually, no problem as yet!
Happy flying year
Your austrian slope-soarer
More Looping
From:Martin Gregorie

Hi Roger,

If you want a real, built, flown, and used-in-competition example of a
full-blown closed-loop model aircraft, you only need to look at the
ALOFT project, which was developed and flown in 2007/8.

It was a 5m span carbon glider that could navigate autonomously round a
predefined course, locating thermals, centring in them, climbing until
it judged that the climb rate was insufficient to justify climbing any
higher and moving on round the course and looking for the next thermal
which was strong enough to justify spending time in it.

ALOFT wasn’t fully autonomous. It was hand flown during launch and
landing, but did operate fully autonomously for the rest of the flight.
It owner was allowed to compete against RC-gliders (flown from the backs
of pickup trucks and convertibles), where it finished on the top half of
the score sheet at a Californian competition in 2008, and won one race

Its development was the subject of a thesis that got its author an
Engineering doctorate. It disappeared from view for a few years while
the spooks looked it over for possible stealth surveillance use, but you
can now find good info about it on the ‘net:

describes the project

reports the contest it was allowed to compete in.

ALOFT initially carried a variometer, but the signal from that was so
noisy that they scrapped it and got climb/sink rates from the on-board
GPS. They fed these into a really neat algorithm that could work out
where the thermal centre was from the last minute or two of GPS
positions, recorded at 1 sec intervals. I reckon the kit now exists to
do the same if it was installed in a FF model, though F1Bs may glide too
slowly for it to be practical.

There is another paper that describes the control and thermal-finding
algorithm, but it seems to have vanished off the ‘net again – spooks
twiching, I bet. Fortunately, I have local copies of all three papers.

This is stuff that isn’t used in full-size gliders: we find thermals
well enough using the variometer and the ‘feel of the air’ as detected
by the pilot’s buttocks and, of course, looking at clouds. However, the
way ALOFT decided the optimum time to leave a thermal probably was
swiped from a full-size glider pilot – its easy to show that, under
conditions when thermal strength tails off noticeably below cloud-base
as you get higher, then your cross-country speed is faster if you find
and use more thermals, leaving each one at a lower altitude than you
would if you had used fewer thermals but rode them to greater heights.
Its counter-intuitive at first sight but definitely works!


Editor’s comment – Note that since the event Martin describes there has been significant advances in small, flying closed loop systems – they are key parts of drone technology from recreational drones on.  For example the ability for a drone to “stay at this location and take photos” needs a closed loop system, same with “fly to this point” or “stay in the box” aka geo fencing.

F1A for sale
From: Ran altman

Hello Roger,
I would like to public my 3 model for sale.
is it possible to publish in  the Sen?
– yes but we do not do pictures

for sale…
I’m selling my  3 short LDA F1A models.
with RDT system, extra stabilizers, 2 palm and accessories..
price  1100$
3100$ for all
For more information..

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Roger Morrell