Su-35 360 VT
As for flight advices, this plane is pretty easy to fly, the only concerns are take-off / landing and lack of power for 3D maneuvers and high alpha.
Take-off: If you have a paved runway there’s no problem at all just get speed and pull up gently. On non paved and grass runways you have a lot of drag and the plane reaches a lower limit speed on the ground. To be able to take off You usually need a huge deflection of elevator on a quick impulse (If you leave the elevator up, it creates even more drag). So better leave TV nozzles active with full rates and pull up hard when plane speeds up. To avoid entering a low altitude cobra (Not a good thing!) release pressure on elevator as soon as the Sukhoi starts to rotate. You may need to press the nose down after take off to level plane and gather speed, be aware not to crash!
If you can program your Transmitter, optimum setup for take off would be FULL TV pitch up and half tailerons deflection. This is because if you have full tailerons deflection, it only creates force at the begining, then they stop producing lift and create drag that do not help the plane rotate (Detached flow on taileron surface). But if the plane manages to rotate, then tailerons effective AoA decreases and flow attaches again, producing more lift efficiency and suddenly making the plane pitch wildly upwards, maybe entering a cobra (It has happened to me a couple of times). With half deflection you limit the “unwanted cobra” risk and probably generate more turning momentum than with full deflection. Full deflection is needed for crazy 3D maneuvers only 😉
Landing: Set all rates to low. Raise nose and keep some 15-30º AoA nose-up attitude at all times. Let the plane loose altitude slowly. Pull a bit more before touch down to further slow down the plane but try not to stall! If you do this too early the plane will gain altitude instead of landing. You need to give a bit of throttle and lower the nose a bit to prevent it from stalling. Take care to remove throttle as soon as the plane lands to avoid sucking debris and damaging the ducted fans.
3D maneuvers: It is very personal, try always first at high altitude and you can later repeat them lower when you gain confidence.
high alpha: Keep nose up pulling on elevator. TV always on. Try not to touch ailerons, make corrections very carefully with rudders. If plane starts twisting out of control, lower the nose and give power, do not try to compensate with ailerons if the plane’s nose is still looking up. Be careful when you start this maneuver too low since it takes time and full throttle to recover the plane to a normal flying attitude again!
Flat spin: Stall the plane and use maximum elevator and rudder deflection with full trottle to enter spin. Regulate spin speed with throttle. DO NOT touch ailerons at any time!
All of this is what I do when flying but you may find better ways to do it ❗
Each one has its own way to fly!
Philosophy of flight: Since this plane tends to be underpowered (less than 1:1 Thrust to weight ratio) it’s good to learn to fly in terms of energy. Especially more if you want to fly 3D. So, speed and altitude are always your friends, you can always convert speed into altitude and altitude into speed, so before you start a high energy consuming maneuver like a cobra, or a drifted snap roll, you better first gain speed either accelerating or diving. After accomplising a maneuver the easiest way to recover speed is diving but you can only do this if you started high, otherwise you rely solely on motor thrust to recover lost energy. So try not to risk dangerous maneuvers at the end of flight!
A couple of pictures for the nose gear reinforcement mod:
(Balsa wood + fiberglass + Epoxi)
The main landing gear replacement (Though I am using a less diameter wheel)
And finally the current and previous electronic setup:
Thank you very good information 😃
Alejandro, Thank you for sharing. Very useful information.
Спасибо!
By the way, I forgot to share this last mod:
Cockpit painted blue-green, Transparent head up display screen and green LED simulating sun reflex on display screen 😉
Hi Alejandro!
Thank you for detailed information about the settings of Su-35, modernisation of the frame, as well as instruction for take-off, landing and aerobatics.This information will allow us move to the next stage. New videos are very good. There is visible illumination in cocpit on your videos. Is it a diode or reflection from pilot*s helmet? What kind of video camera do you use and how to attach it? Do you have experience of flying with help of FPV system?
Thanks Ротор 😃
Yes, I use a green LED to emulate head up display.
We film with Canon EOS 7D from the ground and with hobbyking’s hd wingcam from FPV planes for the air shots:
hobbyking.com/…/__17200__hd_wing_camera_1280x720p_…
We secure the camera to nose of the plane either with velcro or with masking or electric tape.
On the FPV planes we use a separate camera for the FPV purpose, the one on the link is just for recording.
I am still learning to fly FPV on a Bixler plane but I intend to make my L-39 EDF an FPV plane too, but haven’t tried yet (I have like 30 flights on the Bixler but I think I’m ready to move to the jet).
On the air to air video we also used a GoPro hero 3 from an FPV hexacopter for some of the scenes.
Tanks Jandro for your information. Are you flying with vision goggles or screen?
I use Fatshark Predator goggles but only on the bixler right now. I pretend to use them too on the L-39 soon. 😃
And now describe мотоустоновку the su 35
Hi Jandro!
Perhaps there is some risk to fly with goggles without seeing the aircraft from the ground. May be flying through the screen is more safer. What is your opinion on this issue?
It first depends on what is your flight range.
If you are going to fly close, maybe screen is more secure but if you are flying farther than 400-500m you won’t either see the plane so there’s no point in using screen.
If you intend to use a head tracker, you need the goggles too. With goggles you are more inmersed and concentrated on flying and thus you can fly safer.
It is also difficult to properly see anything on a screen with daylight unless you cover yourself and the screen with a towel, in which case you also loose sight of plane.
So I think it’s safer to fly with goggles but if you want to be even safer you can ask a friend pilot to be your copilot and keep always track of the plane while you fly so that you can give him the transmitter if you loose video signal.
You can also do this with teacher-student cable to be faster.
In any case, what will give you more security in flight is to use good equipment (Diversity receivers, multiple Rx good adequate antennas or GPS tracker antenna, OSD + Autopilot…)
This way you first ensure that you have more range but if anything goes wrong you can still hit autopilot or “return home” and wait for the plane to come back until you regain video signal or eye contact.
This, of course, is just my opinion 😉
About the Мотоустановка, I was using the original fans that came with the kit, all posted videos are with these fans. Thrust to weight ratio was about 0.7
This past weekend I installed and tried new engines, Counter-rotating Lander DPS 68mm EDF for 6S Li-Po.
rc-castle.com/shop/product_info.php?products_id=20…
I did some thrust tests and this is the outcome:
SU-35 09/03/2013
Weight
Plane + Rx Batt: 2460g
Main batt: 805g
TOW: 3265g
CG (with gear out)
145mm from CG to wing LE on wing-fuselage joint
170mm from Cg to wing LE on wing’s LE end against body
Measured Thrust on ground: 2200-2300gr
__________________________________
SU-35 19/05/2013
Weight
Plane + Rx Batt: 2744g
Main batt: 841g
TOW: 3585g
CG (with gear out)
148mm from CG to wing LE on wing-fuselage joint
173mm from Cg to wing LE on wing’s LE end against body
Measured Thrust on ground: 2800-3200gr
Please, I insist that you keep speaking in russian!
I will translate and ask by private message if I have any doubt, maybe this way I can learn something! 😁
То-есть насколько понимаю, с лендеровскими импеллерами тяга всеравно меньше 1 получается?
It would be better to have more than 1 to 1 Thrust to weight but it’s very difficult in this plane. Maybe you could do it using 8S LiPo capable motors in PLASTIC fans to reduce weight and improve power.
I bought the lander fans because they are the only high power counter-rotating dynamically balanced EDF set that I know and is sold at a reasonable price.
The all-metal shroud sadly increases the weight a lot 😦 but they are also very efficient 😆 so I can fly more time than if I use 10-12 blade EDFs.
Hi Jandro!
Thanks for yuor opinion about FPV system. I think that flying with copilot using second transmitter is a good idea. Motors for Su-35 is a problem. I think there is no good proposal on the market. When you measured stock EPF trust did you use 10 or 6 blade fans?
When do you need to use tailarons for roll? You said that ailerons should be used with great caution.
Спасибо Alejandro
Это правильно. It’s difficult to find a good combo for this plane, you will get best performance with 5 to 6 blade lightweight and dynamically balanced fans like Wemotecs, eflight V15 housing or some tamjet models (more expensive)
As for the motor, you could try with HET 2W35, Eflight BL32 or Dr. MadThrust 2200kv for 6S LiPo. There can be better options for sure but I don’t know them.
I measured thrust for stock fans with 6 blades. Lander turbines have 5 blades instead.
As for ailerons, you can use them normally like in any other plane but above 30º angle of attack, use of ailerons can lead wings to stall. If you have tailerons and ‘roll - TV’, you need less surface deflection to accomplish the same and they become safter to use (Harder to stall). But sometimes, the use of rudder just works better at high alpha flight.
Болшоые спасибо за терпение!
Напиши мные, пажалуста, по русски. 😉
Всего хорошего!
Интересно, что будет, если в штатных импеллерах моторы заменить на вот эти hobbyking.com/…/__21482__NTM_Prop_Drive_28_36_2700…
сгорят или можно пробовать?
У него обороты больше, а мощность меньше…
но он на 3-4 банки расчитан. На 6S мощность вырастет некисло. Другой вопрос, долго ли протянет 😃
Надо экспериментировать на стенде. Можно же и 5S на него дать.
Есть конечно вообще красивое решение. Найти умельца, который перемотает штатные движки на больший KV и мощность. И с весом проблем не будет, и тягу можно будет поднять. Но где такие умельцы водятся, мне пока не известно. Слышал, что они существуют, и перематывают движки за разумные деньги под любые хар-ки