phil alvirez's blog View Details
Posted by phil alvirez | Oct 19, 2021 @ 12:40 PM | 11,584 Views
who can provide data on being chased by a hawk or whatever?
i ask because i got chased by a hawk.
i was flying my 2 meters electric glider midmorning. when climbing i noticed a bird following my plane but quit when i was near 200 meters.
then i got into a thermal for a while but when lost it and reached 100 meters here the bird came back, this time to remain following my plane and attacking it, sometimes getting very close. i changed direction but here it came until landed. the bird landed at a place so next flight i avoided that area and it did not chase my plane again.
could be that it was nesting?
any1 with experience with something similar is welcome.
here are some videos showing attacks: https://www.google.ca/search?q=model...client=gws-wiz
speaking of hawks, once i made 2 planes that look like birds. 1 left it white (looks like a gull), and the other painted like a hawk. i quit flying it because as soon as i launched it, all birds disappeared. https://static.rcgroups.net/forums/a...2-IMG_3785.jpg
Posted by phil alvirez | Oct 18, 2021 @ 06:57 AM | 17,025 Views
found this article on the differences interesting. i hope you find it too:
http://www.omagdigital.com/publicati...wser&ver=html5
and this too: https://www.google.ca/search?q=induc...client=gws-wiz
well, from this thread i got some comments at the end that seems as it is not so good after all. look
https://www.rcgroups.com/forums/show...model-aircraft
Posted by phil alvirez | Oct 10, 2021 @ 07:46 AM | 29,576 Views
october 9, midmorning, about 20c (70f), 8 kph (5 mi) south wind, flat farmers land all over; 2 meters sailplane. climb to 200 meters (640 ft). vario tells climbing. so i turn and drift with wind until getting too far so turn back south. but then, flying on, straight facing the wind, plane remains at same level, or slight climb.
once back overhead, turn again, follow a cloud and catch another thermal, drifting with the wind and remain on it turning. over and over. later, noticed that flying straight facing the wind or drifting with it, the plane climbs slightly. tried other areas but cant find these conditions. is like a tunnel that runs along the wind where air is going up. this last over 40 minutes. then drifted over other areas. there was some buoyancy and the plane just didnt loose altitude.
when making the approach for landing, took some 10 minutes to land. sky most clear, few low level puffy clouds.
this is the 2nd ultrawhatever experience with non normal thermal conditions where the plane climbs even when not turning.
i hope some1 could bring experience with weird climbing air conditions.
here is the other experience:
Posted by phil alvirez | Jan 27, 2016
soaring: waves and stranger things: corridors
i want to talk about another source for lift, that i have learned recently. it is a narrow band across the wind.
more specifically:
corridor: a stationary invisible narrow band across the wind, that generates lift.
this happened to me at a flat field...Continue Reading
Posted by phil alvirez | Oct 01, 2021 @ 03:34 PM | 10,440 Views
it is a fact: they are here to stay.
they have their advantages and disadvantages. as everything.
what i would like to mention first is that you can run out of power and then the craft drops like a rock. if you are flying power (not gliders) you may notice a loss of power, but that may not give you time to return and land. and with gliders, that dont use the motor except for climbing, there is no way to know it.
if you fly with radios that dont have telemetry, you are at loss. and if your radio has it, then you have to learn how to program them. and that sometimes is burdensome.
then you have to know how to deal with the batteries, chargers, adaptors, connectors...
i have seen fellows that bring a car battery to recharge their batteries at the field!
and then, what size for your plane (capacity, dimensions and weight). what options. where to find them and at what prices (and shipping). at what rate to charge those.
and, as electrics start by just flipping a switch, they are dangerous. you HAVE to add another switch, or learn how to use 1 already in the transmitter, that you dont need or can substitute or live without that function. this way you have to activate it just before launching/taking off.
there is much more to add.
but these are the basic things to consider.
of course, internal combustion (engines) provide more power per weight, but with the increase in limitations due to noise pollution, sometimes there is no other way but electrics.
also, some like the easiness to fly them, as there are no possible problems: just flip the switch and the motor starts.
and for gliders, where you can start the motor any time, as when you drift too far and otherwise you will not be able to return to the field, or when you may fall short when landing, this is something you wouldnt even dream of.
for scale models, there are no engines protruding.
Posted by phil alvirez | Sep 18, 2021 @ 02:58 PM | 10,225 Views
perhaps some data on our source wouldnt hurt.
how were invented and developed is a fascinating story. enjoy.
https://en.wikipedia.org/wiki/Lithium-ion_battery
Posted by phil alvirez | Jul 11, 2021 @ 10:02 AM | 3,716 Views
getting started presents several situations that are worth commenting in detail:
1-what to do;
2-how much movement;
3-how fast;
4-orientation;
5-getting drowsy;
6-getting tired;
7-not getting the feeling;
8-practice.

1-what to do. how do you know what to do to make the plane do whatever you need:
a transmitter has 2 joysticks. the most common way is: left stick: throttle and rudder. push forward means motor runs faster; push left: model turns left.
right stick: forward means dive; left means left wing sinks. now you know what to expect. great!
2-but then you dont know how much movement-that is, until you are flying the model. and most of the time you overthrow. but there is an alternative: simulators!
getting 1 allows you to familiarize with both things: with practice you dont have to think what stick move which way, and also the amount of throw tells you something. and when practicing, if you do something wrong you dont crash the model. this lets you learn way faster and saves you the frustration.
3-also you get some idea of how fast react to any situation. moving slower than needed in some cases the plane does not recover in time; moving too fast in others the plane becomes too flimsy. takes time to learn this too.
4-flying a plane when it is flying away from you is easy: if you want to turn left you just move the stick to the left and the plane follow your command. but when it is moving towards you, you have to move the stick the opposite way. this...Continue Reading
Posted by phil alvirez | Jun 23, 2021 @ 10:22 PM | 18,697 Views
this is dedicated to those who are interested in improving their knowledge on aerodynamics. it is a science that has been applied also to model airplanes.
but is has been discovered that there are some laws that dont apply so well. and took some time and research to learn that indeed, there are laws that are specific for models.
and this is easier to understand by following the next:

Reynolds Number (Re)-A simplified approach.

There is a difference in performance of a wing, depending mainly of its size (chord) and speed, and Osborne Reynolds managed to put that together in an equation that lets us predict its behavior.
In charts that show the lift and drag, the curve changes depending of the Re. The stall, the max lift and drag happen at different angles of attack, and the efficiency changes, too.
There are several ways to determine the Reynolds number. A simplified way is if we multiply the wing chord (in feet) by the speed of the plane (in ft/sec), and then divide it by 0.000157
If we know the speed at which certain airplane is flying (and its chord), we can calculate its Re with this equation (and that speed can be measured with a device called ‘How Fast’). seems that still is available here (and the see how too): http://nemhobby.com/how-fast-p32614.html
Now we are ready for this:

Making sense of it all.

I am presenting this to be analyzed by everybody, and then each one to decide if it makes sense to him.
From the beginning of the 20th...Continue Reading
Posted by phil alvirez | Jun 08, 2021 @ 06:33 PM | 19,153 Views
i fly 2 meters sailplanes. climb with an electric motor to 200 meters in 30 seconds, stop the motor, the propeller folds and i search for thermals to soar.
i spend as much time as the weather conditions allow. 1 day with clear sky (no birds in sight) i went flying and , after the motor stopped i began to search for updrafts. but suddenly, about 50 meters above my plane, i noticed a huge swarm of tiny birds flying fast in all directions. looked as if they were going nuts! as i drifted searching for thermals, i noticed that they moved above my plane. then i turned back to where i was, and they followed my plane. tried every maneuver i could think of, but i realized that they were following me. it was not a coincidence ! as i couldnt find thermals, my plane began to loose height, but they followed me on the descent, until when i was about 60 meters high, they suddenly disappeared. i couldnt believe my eyes again ! how could they show up and vanish so fast? where were they before and after? i did 3 more flights and same story. as i recalled, they looked like swallows, but that was all that i could learn. took me some time searching to learn that they were swifts. what could they see in my plane to remain above it? and not so close, just above...
and this never happened again.
https://www.google.ca/search?q=pics+...fGwDjkQ4dUDCA4
https://www.google.ca/search?q=pics+...c7mAScQ4dUDCA4
wonders of the sky, that even when you think you knew all, it has something to amaze you!
Posted by phil alvirez | May 19, 2021 @ 01:50 PM | 37,991 Views
once i lived in a house that had a large trellis that covered the whole sides including windows. to trim it to clear the windows i had to chase a fellow gardener that had a tall ladder, but couldnt find him before 11:00 am. when i asked him why i couldnt find him before that time he said that he didnt need to work before to get all the money he needed. at the time i found this silly, but after many years chasing more money, i failed to realize that what matters is to understand what you really need to be happy.
now that am retired and live a quiet comfortable life i see the wisdom of that modest fellow that was aware of what he needed to be happy and didnt push beyond that. to me, learning this is the key to happiness.
Posted by phil alvirez | Mar 30, 2021 @ 10:22 AM | 10,919 Views
there is a time when suddenly you see the light. and the way is to see things from afar.
and to me is now. i have been into model airplanes since i was 5, and even with interruptions for building or even just flying, they have been in my heart all the time. my fascination was to catch a thermal (those days there was only free flight), and still is now. i fly sailplanes with remote control (r/c).
even if things have changed beyond the wildest dream. now we have this electronics technology everywhere. and this adds another factor that i wouldnt even think about before: that now i can detect thermals and chase them! so, whenever the weather allows, am at the field, having the time of my life!
but i got carried away with this fascinating technology. so many radios, batteries, motors, electronic speed controllers, batteries, whatever, so much to learn, to try, it has become and endless race to catch up, and that has brought us into a whirlwind that does not allow us to see what really is going on.
recently i have been struggling with some parts that are not behaving as expected, when i realized that, well, perhaps i really dont need them. that simple!
so am going back to basics. what i really need to hunt thermals?
and this also applies to whatever specialty you guys are into: what are you guys aiming at? are you enjoying it? that is what really matters!
are you going too far? thats up to you to decide. but this is just a wakeup call, thats all.
think about it... and enjoy this wonderful hobby the best possible way. cheers!
Bird’s Secret To Soaring Super High (3 min 9 sec)

Posted by phil alvirez | Nov 01, 2020 @ 03:14 PM | 17,753 Views
just in case you havent heard of the latest, here are some of the possibilities for better batteries:

https://www.pocket-lint.com/gadgets/...r-over-the-air

enjoy
Posted by phil alvirez | Oct 16, 2020 @ 09:32 AM | 14,199 Views
Posted by phil alvirez | May 28, 2020 @ 11:46 AM | 17,279 Views
see parts 1-3 at my blog
from time to time, model airplane magazines published articles on sort of science fiction by mad scientists that were performing experiments with remote controlled airplanes.
these were as rudimentary as they could be. free flight planes controlling just the rudder, and that happened erratically. it was sort of lottery to be able to change the direction of the plane now and then.
but, as i said, it was just trying the boundaries of the then fantasy of controlling something at a distance.
this took years and the contribution of countless (and nameless) folks to reach the point of being able to control also elevator, then throttle.
the gear consisted on a car battery placed on the ground that provided the power, connected to a control box that the modeler held in his hands.
those who were present were in awe, and talked about this for a long time to whoever were around.
then came reeds, that improved efficiency. there was 1 channel for left turn, and another for right turn.
when elevator was added, same thing: 1 channel for up, another for down.
then servos. nicads. years later, some1 released the 1st commercial radio control (kraft, i think). and expensive. heavy.
and they were flying on frequencies (72, 27), so you would not have interference.
i recall at los angeles, there was at a place called mile square, that was an emergency airstrip (dont know of still exists), that had large areas designated for each frequency where the ones that were willing to fly formed and awaited for their turn to fly.
it was until, on 2006 that horizon released the 2.4 with which apparently any number of planes could fly without interference.
now we also have cellulars, laptops, gps and whatnot.
boy, the world has come a long way...
pics: https://www.google.ca/search?hl=en&s...TkwASYQ4dUDCAw
Posted by phil alvirez | May 27, 2020 @ 06:23 AM | 26,280 Views
see parts 1 and 2 at my blog
also there was control-line: you fly the plane attached to 2 thin cables that are connected to a handle, like a pistol grip. you aim higher, the plane climbs. aim lower, it dives. turn and turn. and you had to overcome dizziness.
once you did, then try loops. wing overs. fly inverted (signals are reversed). then more stunts.
there was a competition pattern, where you had a sequence of maneuvers.
there was also combat, where 2 planes flew at same time. there was a streamer attached to the tail, and you aimed to cut it. the closer the more points you got.
and there was speed too.
we had lots of fun.
here, we could control the airplane.
a new experience.
pics: https://www.google.ca/search?hl=en&s...fd7D7kQ4dUDCA0
Posted by phil alvirez | May 19, 2020 @ 07:51 AM | 16,277 Views
(see part 1 at my blog)
free flight
pics: https://www.google.ca/search?hl=en&s...ekCAicQ4dUDCA0
from my childhood i had this fascination with the matters of the air.
and it was when i discovered the library that i began to learn all about it.
there were books on aviation. and some on model aviation. and magazines.
and didnt have enough of all. as i began to build models, i had the chance to learn countless things on how to build them and fly them. but that meant to learn aerodynamics. a lot. otherwise the planes wouldnt fly. besides building accurately, there were all kinds of details.
the way was free flight. meaning, that once the plane is flying, it is free. you have no control over it.
there were 3 basic types: gliders, rubber powered, and engine. gliders could be hand launch or towline.
hand launch were the cheapest: just solid balsa wood. but had to be built accurately. otherwise wouldnt fly.
and then learned about thermals: updraft currents that could carry the planes away. magic! i learned to detect them and see my planes raising, sometimes out of sight.
and there were towline gliders: those were built up, like the kits i had been building, and that we towed and released up there, with more chances to catch a thermal.
and the rubber powered were another challenge: to deal with the torque; how to wind them, and the propeller: fixed, free wheeling, or folding.
the engine powered were the most expensive. engines were spark, then came glow plug...
an unlimited universe up there for me to enjoy.
( and if any1 has experiences, please bring them. this is for all to participate)
Posted by phil alvirez | May 18, 2020 @ 08:43 AM | 18,672 Views
life changes. it does all the time. some times gradually, others suddenly.
like now. things were different. better, we could say.
we had things that didnt appreciate. that will not have again.
in a sense, is like growing old.
still, we can count our blessings.
we still have things that we can enjoy.
for instance,we could find the way to fly our models. to adapt to circumstances.
may not be in close contact with friends, but still talk at a distance.
and we have means like this, where nothing has changed.
and we can watch the tv. and movies in the internet. documentaries. anything.
we still can exchange ideas, learn new things, new ways.
so much to learn.
if you also consider that we still can dream, to write about our experiences, fantasies, dreams, just as i am doing here now.
talk about our life.
anything.
so, why dont we start now?

1-let me tell you about my life with the air. flying things. the weather.
from my 1st memories, my fascination with the air has remained alive and well.
i recall watching in awe flies-how they fly-birds, airplanes. the clouds, the weather...
then i found at toys stores tiny gliders, and an uncle taught me to make paper planes.
and when i was 9 i saw at a gifts store a box with the drawing of an airplane, and i bought it. it was an airplane called apache (later renamed mustang).
it came with everything to build it: rolled plans, balsa sheets with printed pieces to cut; sticks for spars, tissue paper for covering, rubber strips, propeller blank, glue, and the plans were full of instructions. i had the time of my life!
it was the beginning of a long life of building and flying model airplanes-that still do and enjoy.
Posted by phil alvirez | Feb 21, 2020 @ 02:57 PM | 17,036 Views
once i was enjoying a perfect day, no clouds, just catching flies, when noticed a monarch butterfly doing its typical wandering flying, at about 30 feet, when suddenly she began to circle and stopped flapping its wings...and began to climb fast. she had got a surface thermal, the kind of rising warm air, and in no time disappeared. i couldnt believe my eyes. no idea that they know how to make use of those currents.
then began searching and found some data that sounds like sci-fi at its wildest. just look:
monarchs: https://www.google.ca/search?hl=en&s...30.dTuf-K1wNyU
then, as if that is not enough, i learned about other that go even further:
https://www.york.ac.uk/news-and-even...ady-migration/
and we are superior species?
Posted by phil alvirez | Jun 15, 2019 @ 02:44 PM | 17,048 Views
maverick 3-the ultimate
the maverick 3 is basically the same as the previous 2.
when realized that i couldnt find another way to improve its performance by design, i tried to improve its structure.
so the only change is the fuselage, which is now carbon fiber/kevlar.
i found the magellan 2 meters the most suitable. and it is (or was) available at the time.
http://www.icare-rc.com/magellan_e.htm
Magellan-E - ICARUS
The Magellan electric is the continuing effort in development after the popular Carbon D-light and Koleos series of electric gliders from ICARE.They are based on the same moulded carbon D-box technology that made the Carbon D-light so successful. This type of construction results in a very strong, light wing and a very accurate airfoil shape over the leading edge - the most important part of ...
www.icare-rc.com

it ended up being lighter, stronger, with more room, and more streamlined. and still better performance!
i had to modify it extensively due to that it has a longer tail moment and shorter nose moment. the solution was to move the wing back 30mm. this required substancial changes, but works fine. also the tail is designed for v and mine is t. the end is wide open so i made a fairing to streamline it. but it worked fine.