RC India

Whether you are a scratch builder or you built your aeroplane from a ARF kit, most important event is the maiden flight, even the best of the RC pilots have butterflies, :o thinking of Maiden Flight.(After having done a lot of simulator and you are confident to go) biggest worry being take off, there were some discussion earlier , however those are not properly documented therefore  I am starting this thread, sharing the first lesson Take Off

1. First and Foremost you should take off into the wind not at an angle to the wind
2. Light wind is preferable to no wind or strong winds
3. Visibility should be at least 1 kms (to avoid orientation confusion)
4. there should no fog or low clouds.
5. after proper control and power plant check run her on the ground,see her ground manoeuvrings , in terms ground looping tendency nose over etc. carry out small hops (Get airborne a few inches and land back straight ahead following the technique enumerated below)
6. while taking off stand with aircraft facing exactly away from you bang on into the wind (You should feel the wind on your face), Simply put you should stand astride the FRL (Fuselage reference line ) of the aircraft.
7. If you don't have a wind sock, pluck some grass and throw i over in front and above you. you will get a fair idea of the wind.
8. I follow 'Open Throttle as you Run' technique some open full throttle before release, for maiden i don't recommend that (Except if you suspect the engine will quit if you open as you run) slowly open throttle with very little back elevator,
9. let the aircraft run on the ground, slowly increase power to half to slightly more than half (this will depend on your Thrust to wt ratio) Never full.
10. when the aircraft attains correct speed she will on her own climb away from the ground.
11. let her fly away from the ground at very shallow climb angle.
12. do not maneuver except for positional turns till you attain safe altitude.
13. If launching SkySurfer or a easy star kinda aeroplane, DO NOT make the mistake of chucking with full power, she will surely pitch down viciously and you give excessive correction, pitch up and crash. THE KEY is open power only so much that she is tending to slightly sliding out of your hand. chuck it from a higher to lower ground if possible and available, if not it is fine. During Chuck ensure wings are level and chuck it like a javelin. after chuck slowly open power and climb away GENTLY.


Congrats you successfully Took Off  :thumbsup:

Also read this thread

 from Un-initiated to RC Pilot in 30 Days  (http://www.rcindia.org/beginners-zone/from-a-un-initiated-to-rc-pilot-in-30-days/)

To add on to what Gusty says above and even before you have ventured to the field
1. Do your homework.
   (a) Check the airframe throughly. A second pair of eyes going over eyerything is even more preferrable
   (b) Check engine mounting is secure, plug is tight (glow and gas) all connections to the engine in terms of
    throttle  linkage are secure
   (c) Check all servos operate full and control surfaces do not bind and are set as per recommended travel 
    ranges (atleast on low rates, you can set more travel on high rate switches)
   (d) Check and double check the CG as per recommendations to start with. High wing CG is checked right side up,
    low wing you check CG the model inverted. Fuel tank empty and if you have retracts they are up and locked.
    Similarly also check lateral CG. Any CG issues should be corrected by either shifting the equipment (if possible) or
    adding weight. Remember useful weight, like a bigger (and heavier) battery pack is better than dead weight.   
   (e) Ensure that the clunk in the tank is free and rattles around when the model is shaken. All and any battery
    packs and Rx is secure and would not fall off due to vibrations or flight loads. Give the model a few good shakes
    so that any thing which can shake apart does so now not at the field
   (f) If possible, give the engine a run at home in the model. Any issues would show up and can be adjusted now.
2. At the field, ensure the Rx antenna is extended and not neatly left coiled in the model (if you are still on MHz)
3. Carry out a range check with engine off and engine on (restrain the model while doing this)
4. To disagree with what has been put forth by Gusty above, I would suggest do not hold up elevator for a nose wheeler. This may lead to premature unsticking/rotation and subsequent stall. If it is a tail dragger, you do need to hold up elevator depending on the model to keep the tail wheel on ground and give you better steering while the speed is building up. Start releasing the up elevator as speed builds up and let it come up to neutral. The tail should rise on its own (the tail starts flying), let the speed build up further and the model will ROG on its own or a small blip of up elev should see it unstick.
5. Have some one stand by you (preferrably who flies same mode) to assist you with trim tabs in case they are grossly out.

Sticky-ied !

What i do for nose wheel aircraft is give one jab of trim back from the neutral and run it until she attains adequate and more speed on ground. more often than not she unsticks on her own, assist her upward travel. I have seen people yanking back on the stick for take off go into one uncontrolled climb and eventually, aerodynamically stall into the ground, worse i have even seen guys loop back onto themselves and hurt the bystanders and spectators.

For a tail dragger, it is recommended that you push forward slightly get the tail off the grd and then once attaining right speed lift off, however i will not recommend that for maiden flight, there is danger of touching prop worse nose over

Hmmm good information. Thanks!!!

Thanks a lot.....  :thumbsup:

To continue from where I left.
6. If using computer radio with multiple model memories, ensure you are at the correct model selection.
7. All the switches on the radio are in the position they should be
8. If using a non computer radio, ensure all your trims are centred and all flying surfaces are neutral, view from different angles to ensure this. Some time surfaces which may look ok from top would be found to be out of alignment when viewed from rear and in line with the surface.
9. Stand behind the model, operate each surface while saying what you are doing, Like pull up the elvator stick and say up. Check if the surfaces operate in right direction. Repeat this for all surfaces in all appropriate directions

absolutely

1. in fact i call out  left up, right up, elev up, elev down, while operating the control column and see if the control surface has moved in the same sense. including after changing the batt in elect aircraft

2. agree with the radio , if you are using DR, Flap ele mix, ele flap mix etc etc. very very important. but then by the time you reach advance mix, you would have sorted out your basic flying, so you can put these radio mix issues in the back burner as far as the maiden is concerned.

Very Important
is the fact some of the model making companies (ESP phoenix models) do not specify low rate/ high rate throws separately for their 3D aeroplane, in that case 40% is a safe figure for elev aileron throw with -50% expo (Remember -50% not +50%, + is used for countering over bearing gyro)for maiden take off ldg,  and couple of flights after that should be at low rate.

-50 or +50 depends on the radio.  On Futaba it is -50, on Spektrum/JR it is +50.  The rule of thumb, for the ones which display the expo curve graphically on the radio console, is to bring the curve closer to the horizontal axis around the center.

This thread is about a year late from my view  :-( I could have saved a lot of foam and time

But, a very important thread no doubt. Keep it up folks. Suggestions would be to include some short videos for demo purpose

Pankaj

First Flight Profile

The very first flight is to check out a number of things those are.

(a) Stall Characteristics of the aeroplane, line up the plane from Right to Left (Most people prefer tis direction, for whatever reason i don't know) reduce throttle to idle (or to a point where you think  your engine won't quit) maintain ht y slowly raising nose and see nose angle and speed at which the stall , happens, approx 30% more should be the landing speed. Be advised speed on a RC varies depending o winds, what doesn't change much is the Angle of Attack indicated by the angle of the nose with respect to the earth's horizontal, in a straight and level flight. in a descent or climb it is measured with respect o the flight path.

(b) Roll rate and roll stop rate initially restrict to 45 deg AOB, do not roll , if nose goes down you may not have the elevator power to pull her up.

(c) Stall in a turn, turn at low speed and see where the nose drops, that speed becomes your min speed in a turn for that angle of bank and power.

(d) Glide.  Please check straight glide and ht loss in a straight glide and ht loss in a turn, remember the aeroplane looses more ht in a turn, which means the angle of descent gets steeper in a turn, if you maintain same Rate of descent in a turn , she will stall, most accident i have seen is in the baselg turn where people do not increase the ROD and the aircraft stalls into the grd.

(e) Carry out couple of circuit and overshoots.

(g) Land before engine quits

Just loud thinking, I guess. But shouldn't a novice not attempt a maiden flight? And someone with experience would - or at least should - be aware of the check lists!

i guess only after sim, buddy chord flying, cleared to fly solo by ur instructor should you attempt your first maiden. absolutely with sushil sir on this

Wonder if this thread should be renamed to reflect "maiden SOLO" flights ? :)

Dont we all in our exuberance and excitment of a new model, do forget a few things which may prove critical?
And escpecially when it is amaiden flight, there are so many things to remember that one may tend to miss out something.
Therefore the thread is a reminder for all, whether you are a novice or with 1000's of hours of stick time.
 

On the lighter side

Let me enumerate some of the stupidest things i have done and learnt in life (Learn from others mistakes, Learn from mine)

1. Took off with Glow booster on the model, discovered by wife when she was previewing the pic on the cam, while the model was still in air. Prolux Booster held on.

2. took off with wheel collet nut loose, wheel fell off during take off, landed without a wheel

3. Aileron servo was kept in place never screwed on, flew 6-7 sorties before realising the folly (In fact suspected some problem in left roll, landed and discovered this to my utter horror).

4. Engine mount and the engine came off on the spit fire, landed safely though

5. Rudder was  reversed

6. flew a wrong model on the radio, had a harrowing time landing as the aileron was reversed and ele throw was too little

7. filled gas on a glow engine (My help did) fortunately didn't start, smell gave away. both fuel caddy were anderson red.

8. had a mid air kiss (Landed fortunately) following a wrong circuit pattern.

9. flew with a loose glow plug, had many engine cut and dead stick on a reliable engine that day

Off hand all that i could remember

For hand launch model, always launch leveled and dont aim the plane upwards.
If there is even a slight slope on your flying field, use it and launch down the slope while making sure you are launching in the wind.

yeah, if you go to a known field there is an expert launcher, who only launches aeroplanes

PS
SLS , back to your Avatar ? suits you ? better than that gif

My stupidest thing; taking off with antenna retracted (pre GHz).

The Joy Allukas jewellery shop person's plane crashed soon after take of because ATF was filled in instead of AVGAS- 4 dead.
both engines stopped soon after take-off. probably there was enough fuel in a header tank for the bird to take-off.
avijit

Sushil sir, I'm with u on that, though not on my solo but much later. Now even though I fly 2.4, in my mind I go through the pneumonic FM RAC (Fuel, Model memory, Range Check, Antenna and Controls). Hope this is helpful tip.
Doc

My stupidity and I did this twice not once!
1. On two ocassions, after starting the model, was perplexed to see the engine would not throttle up. It would start fine, idle very well but simply refuse to pick up when throttle was opened.
This continued till the time when opening up throttle, there was a fairly loud pop sound and something flew off from under the modle and the engine instantly picked up revs.
I generally use carb covers over the exhaust outlets and carbs on my models when done flying and when stored. In both the cases, the engine was used with a pitts muffler and both the outlets were covered with the covers.
I guess I should now use flags with "remove before flight" tags so that these are more obvious
 

something like this ?

hi Augustine..i had read in one of you reply... u had suggested to keep a negative expo on the elevator n aileron (means more throw rate near the centre and less towards the end) ...wont that make the stick too sensitive to handle...??

For Futaba, negative expo calms the response around the center.

http://www.rcindia.org/gas-glow-nitro-planes/my-first-50-cc-gasser-build-thread/msg36395/#msg36395

http://www.rcindia.org/rc-general-topics/question-dual-rates-and-exponential/msg12294/#msg12294

Alam
See anwar's rep above, - ve or +ve depending on the radio, basically non linear control throw with less throw in the centre.

After a while I realized , it is better to fly with the radio on a radio tray for maiden, allows you to trim easily. The only aeroplane I didn't have to trim in a maiden flight was addiction x,
Will put pics of my two trays, one diy and the other one is a cf radio tray

Key to Sucessful maiden is a good take off. After take off most airplanes will pitch down / up and or roll to either side.

(a) for a clean take off, attain sufficient speed before lift off and lift off very gently. After getting air borne continue climbing to a sufficient height before turning, if required continue your climb further
(b) attempt to trim now. Never before you attain sufficient. Height.

Common mistakes

Too much of power on run, premature yanking back on the stick, premature turn, leveling out at low height and attempting to trim by leaving the stick, not knowing where the switches are and attempting to look at the radio for finding the switch.

I have made it a habit to have another pilot standing by for trim changes. This way one never needs to take ones eyes off the model.

In real life aeroplane we have something called a 'cockpit blind fold check'. As the name suggests you are suppose to reach for all relevant switches blindfolded. in RC I would strongly suggest to get comfortable with the radio soon, should be able to reach all switches correctly without hesitation without looking at it. It will remove a lot of your anxiety.

This is a what not to do video,
(a) too steep a climb
(b) very early reduction of throttle
(c) too much of rudder to turn

this is called a classic stalled spiral, where due to Yaw the inner wing stalls while the outer wing continues to produce lift , recovery from this is to 'neutralise rudder and take off bank and get wings level, open power and ease out of the dive'

http://www.youtube.com/watch?v=IlSqpf5jFvw

in the initial stages of your RC Flying you never use rudder.  turns are accomplished by putting on bank (Not more than 20 deg to 30 deg ) and giving very slight elevator

here is one good book for all newbies and intermediates

http://www.ultraligero.net/Cursos/radio_control/the_complete_beginners_guide_to_flying_radio_control.pdf

Wow sir its a complete Guide with nearly all topics covered.  :hatsoff: :hatsoff: :hatsoff:

Sir a million thanks for the book.. its a treassure for any one may be a beginner or expert.. :salute: :salute: :salute:

Super book! Thank you Augustine sir :)


+1

But then why do most basic trainers don't have a ailerons and have only rudder with dihedral in wings (easy star/easy cub)?

From my experience, I started with using ailerons and I hardly used rudder. Now I have got so used to it that I find it very difficult to use rudder, which is very important while making last minute changes to landing approaches. I have many times crashed sideways while landing when using ailerons in the last moment to change directions.

on the subject of a maiden - can anyone tell me
of a tx that has cross trims

Gusty

Having had this plane, I would consider it as almost impossible to fly. Extremely sluggish - described by somebody as a "fat lady" ( a great looker though). Would certainly have had a direct contribution to the crash.

Discarded the plane after 2 flying sessions.

Most, modern, programmable Txs have trims that can be assigned so you can choose between cross or normal. The rationale behind cross trims is that you can use the hand that is not on the control stick, for trimming.

Pretty sure the higher end Futaba radios have programmable trim buttons... the trim control for any channel can be assigned to  any one of the available trims.  Of course, on these radios, any flight function (aileron, elevator, throttle etc) can be assigned to any channel too.  The 8FG has it, and so does the 12channel and higher radios.  The name of the menu is "FUNCTION".

Not sure about other brands... did not look them up.

i am using 14 mz and SD 10g , both has this function

Vishal
i hope in a 3 channel (The one which does not have aileron) aeroplane you are connecting rudder servo to aileron channel?

Augustine sir, I'm having both ailerons and rudder in my plane/radio (Sanwa 6G), but I'm so used to using ailerons that I don't use rudder. One main reason being that the throttle changes every time I use rudder  ;D I have to start practicing using only rudder for some time now, till my thumb gets steady.

This is called Vital Actions Before Take off (Modified for RC Flying)

We in real life memorize using mnemonics called TAFFIHC (Pronounced taffiHC)

T-- Trim- Neutral, correct DR selected
A-- Ac Clean (Not clean , clean, in Clean configuration, which means, If using Air brakes they are in, no hatch is open etc)
F--- Flaps are one notch down (Two notch will create drag and take off run may suffer)
F--- Fuel Adequate
I--- All instruments (Servo, Battery, Receiver, Connections all are "GO")
H-- Hood (Canopy is closed and secured)
C--- Correct model selected, Control Moving in the correct Sense (I move the stick to the Left and call to myself "Left Up", Stick to the Right call "Right Up", Stick Back call "Ele Up" Stick Forward call "Ele down". Rudder Stick Left "Rud Left" and Rudder stick right call "Rudder Right", takes a while to write, very little time to do it)

CG Calculator

http://www.scaleaero.com/CG_Calculator.htm

Planning to debut my plane soon. So many pointers to keep in mind ...  ???