YAK 54 Crash during maiden flight
10-22-2007, 08:45 PM
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YAK 54 Crash during maiden flight
This is my first YAK54 size 40 from rich model after YAK54 ep from B/Horse. I assemble it nicely and checked the cg, control throw before flying and everything seems to be ok. It was nicely taxing and smooth takeoff and after about 4-5 metres high it started to banked to right and as usual, I counter it but nothing happen to the plane. It keep bending slowly and crashed. I was wondering what went wrong, one thing is I fly it without cowling. required engine is .52 4c and I'm using .56 4c, 12.25 x 3.75 prop. Anyone knows what went wrong ? is this because of no cowling install and caused air brake at the firewall ?
10-22-2007, 09:13 PM
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RE: YAK 54 Crash during maiden flight
Impossible to tell from the limited information but 3 admittedly wild guesses are disconnected ailerons, reversed ailerons or a departure stall.
Absence of a cowl should not be a factor.
Absence of a cowl should not be a factor.
10-22-2007, 09:19 PM
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RE: YAK 54 Crash during maiden flight
Zul come to KD and look for one Mr Tan ... he flies with no cowling all the time! Looks like what they guys say might be the answer. You did not hook up the ailerons or it was hooked up in reverse. Again, without enough speed it might have stalled. Did you gun the engine or did you take it easy for a slow lift off?
10-23-2007, 12:08 AM
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RE: YAK 54 Crash during maiden flight
As this plane very light compare to other plane in its 40 size, in the manual written 2c engine required is .40 or 4c is .52 and i'm using saito .56. I was wondering also because usually .40 2c engine required .60 4c engine. I have a friend fly same model and specs as mine but no problem at all. For the engine trust, as you see in the picture, mounting box at firewall comes preinstalled with the trust line and for the radio, I did check in front of me everything in order just before take off, but I wondering if the radio had problem but the next day I fly my cap232 with the same radio, receiver and battery and no problem at all. If say engine not enough power, the plane start to take off easily after few metres taxing on the ground. I did check everything also after crash, the aeileron and others, it seems nothing wrong. I only check the CG and did not do balancing nose to tail but everyhing I place centre of the body. Anyone please look at he picture of engine mounted, anything wrong with it ? Is it suppose to bend to left or right f the trust to much on the right ?
10-23-2007, 01:43 AM
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RE: YAK 54 Crash during maiden flight
tiANci, what makes you think its engine trust problem, could you explain to me. from the picture you saw, am i wrongly installed the engine ? am i right to say if the engine trust more to right it will bend to left or with slight aeileron control input, it will correct the balance. I'm getting another unit and now building it but i'm afraid the same problem happen again. you know lah..how much i spent for 2 units
10-23-2007, 02:29 AM
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RE: YAK 54 Crash during maiden flight
Hard to tell the reason why behave like that. If you checked everything before flight, all are OK, then might be aileron loosen uP, during takeoff vibration, or servos gone mad/loss connection with receiver..
It happened to me once, checked everything OK, then punch for take off, drifted left and cannot counter.. upo checking the dual servo, one of the servo on the left, is not screwed in and popep off...just imagine 90 powered scale plane at full take off speed.. whew almost collecting balsa dusts..
sorry for what happen to you.. check you antenna also, might be loose or broken wire inside reciever... who knows
It happened to me once, checked everything OK, then punch for take off, drifted left and cannot counter.. upo checking the dual servo, one of the servo on the left, is not screwed in and popep off...just imagine 90 powered scale plane at full take off speed.. whew almost collecting balsa dusts..
sorry for what happen to you.. check you antenna also, might be loose or broken wire inside reciever... who knows
10-23-2007, 02:33 AM
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RE: YAK 54 Crash during maiden flight
ORIGINAL: zul_cessna
tiANci, what makes you think its engine trust problem, could you explain to me. from the picture you saw, am i wrongly installed the engine ? am i right to say if the engine trust more to right it will bend to left or with slight aeileron control input, it will correct the balance. I'm getting another unit and now building it but i'm afraid the same problem happen again. you know lah..how much i spent for 2 units
tiANci, what makes you think its engine trust problem, could you explain to me. from the picture you saw, am i wrongly installed the engine ? am i right to say if the engine trust more to right it will bend to left or with slight aeileron control input, it will correct the balance. I'm getting another unit and now building it but i'm afraid the same problem happen again. you know lah..how much i spent for 2 units
10-23-2007, 03:05 AM
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RE: YAK 54 Crash during maiden flight
ORIGINAL: zul_cessna
As this plane very light compare to other plane in its 40 size, in the manual written 2c engine required is .40 or 4c is .52 and i'm using saito .56. I was wondering also because usually .40 2c engine required .60 4c engine. I have a friend fly same model and specs as mine but no problem at all. For the engine trust, as you see in the picture, mounting box at firewall comes preinstalled with the trust line and for the radio, I did check in front of me everything in order just before take off, but I wondering if the radio had problem but the next day I fly my cap232 with the same radio, receiver and battery and no problem at all. If say engine not enough power, the plane start to take off easily after few metres taxing on the ground. I did check everything also after crash, the aeileron and others, it seems nothing wrong. I only check the CG and did not do balancing nose to tail but everyhing I place centre of the body. Anyone please look at he picture of engine mounted, anything wrong with it ? Is it suppose to bend to left or right f the trust to much on the right ?
As this plane very light compare to other plane in its 40 size, in the manual written 2c engine required is .40 or 4c is .52 and i'm using saito .56. I was wondering also because usually .40 2c engine required .60 4c engine. I have a friend fly same model and specs as mine but no problem at all. For the engine trust, as you see in the picture, mounting box at firewall comes preinstalled with the trust line and for the radio, I did check in front of me everything in order just before take off, but I wondering if the radio had problem but the next day I fly my cap232 with the same radio, receiver and battery and no problem at all. If say engine not enough power, the plane start to take off easily after few metres taxing on the ground. I did check everything also after crash, the aeileron and others, it seems nothing wrong. I only check the CG and did not do balancing nose to tail but everyhing I place centre of the body. Anyone please look at he picture of engine mounted, anything wrong with it ? Is it suppose to bend to left or right f the trust to much on the right ?
10-23-2007, 03:49 AM
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RE: YAK 54 Crash during maiden flight
The reason i need the xplaination so that i can correct what i did wrong, no offend. if the engine i installed no problem with the trust line, i believe problem from other factor, rx, crystal, servo connector. maybe not my luck for this one....
10-23-2007, 05:08 AM
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RE: YAK 54 Crash during maiden flight
zul - do a range check. It might be the way you fly. You may have lifted off too slow. To be frank a full 40 sized scale aerobatic plane is not all that happy with a Saito 56, something like a SE 5 is ok but not a scale aerobatic plane that has tapered wings. You MAY have stalled, that is why the plane dropped a wing and you felt no controls. When you stall there is no control as there insufficient air over the control surfaces.
If everything seems ok after the crash then its either a glitch, bad connection or a stall ... I think its a stall ... you were too slow or climbed out at too steep an angle. Next time let the plane have a longer roll out and when it starts to twitch you know she wants to lift off then rotate her and climb at about 15 degrees only.
If everything seems ok after the crash then its either a glitch, bad connection or a stall ... I think its a stall ... you were too slow or climbed out at too steep an angle. Next time let the plane have a longer roll out and when it starts to twitch you know she wants to lift off then rotate her and climb at about 15 degrees only.
10-23-2007, 09:30 AM
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RE: YAK 54 Crash during maiden flight
tiANci & X Man, i agree with you, i think it stalled because not sufficient power, recommended 2c engine is .46 - .50 size and 4c is .52 . I think its wierd, coz usually .50 2c already equivalent to .70 4c, am i right. x man, would it no too nose heavy if i use saito .80 ? kindly advice, here are the specs http://richmodelusa.com/Products/YAK54-40.html
10-23-2007, 11:15 AM
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RE: YAK 54 Crash during maiden flight
Carefully finessed, a .25 is capable of dragging that airplane into the air and doing level flight and a landing, I don't think "not enough power" is the problem. Barring mechanical failure, it sounds to me like it was taken off too slow and started to wallow once ground effect was gone.
10-23-2007, 12:05 PM
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RE: YAK 54 Crash during maiden flight
Zul - the Saito 80 is heavy compared with the Saito 72 or 82. I suspect it will come out slightly nose heavy. Also, on the Saito 56 you can actually turn a 12x6 on 25% nitro. All the best on the next outing!
10-23-2007, 07:57 PM
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RE: YAK 54 Crash during maiden flight
ORIGINAL: zul_cessna
tiANci & X Man, i agree with you, i think it stalled because not sufficient power, recommended 2c engine is .46 - .50 size and 4c is .52 . I think its wierd, coz usually .50 2c already equivalent to .70 4c, am i right. x man, would it no too nose heavy if i use saito .80 ? kindly advice, here are the specs http://richmodelusa.com/Products/YAK54-40.html
tiANci & X Man, i agree with you, i think it stalled because not sufficient power, recommended 2c engine is .46 - .50 size and 4c is .52 . I think its wierd, coz usually .50 2c already equivalent to .70 4c, am i right. x man, would it no too nose heavy if i use saito .80 ? kindly advice, here are the specs http://richmodelusa.com/Products/YAK54-40.html
It always good to have some reserve power, to recover from mistakes.
A .52 4S is the minimum as recommended.
You should be able to fly with it, as what Cutaway said, level flight and a landing, however You will have to maintain a very gentle climb rate, yank the elevator too much, you will go into a stall. Its Purely for breezing around, can't really do much high spirited aerobatics stuff....
10-23-2007, 10:31 PM
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RE: YAK 54 Crash during maiden flight
Zul ... too many people say too many things without analysing. Too many people blame the radio when its not. When you stall a plane, there is no control, I have experienced it a couple of times. There are just too many people out there who talk WITHOUT experience, they tell you things they heard before and may not fully understand. I love the other advice you got about expo etc. We seem to like to scratch our noses in the hard way and not keep it simple. Still make sure you check all your connections and the radio too ...
10-23-2007, 10:58 PM
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RE: YAK 54 Crash during maiden flight
I really doubt the cause is PCM lockout...
, wing stall might be the culprit..
During a stall, and without ample power, you won't be able to recover from it, at around 4~5mtrs off ground... No matter what counter/corrective actions you gave it. At a Higher altitude, say about, 10~15mtrs, you may have a chance.
My 2cents...
, wing stall might be the culprit.. During a stall, and without ample power, you won't be able to recover from it, at around 4~5mtrs off ground... No matter what counter/corrective actions you gave it. At a Higher altitude, say about, 10~15mtrs, you may have a chance.
My 2cents...
10-23-2007, 11:32 PM
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RE: YAK 54 Crash during maiden flight
I believe its not enough power to correct the plane, I have flown mentor with minimum 2c engine (OS .40) but its character is different, YAK EP 25 size with .25 engine 2c (.15 minimum) and no problem at all. Would it be ok if I put .61 ASP 4c engine, is there big different of power from .56 compare to .61 ? weight almost same
10-23-2007, 11:41 PM
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RE: YAK 54 Crash during maiden flight
Zul - your Yak will probably fly with a Saito 56 but you just need more air speed. I think a Magnum/ASP 61 4C is not that much more powerful than the Saito 56. If you want power then go with the Saito 72/82. The Magnum 61 was put on the CMPro Katana 50 ... well, she just had enough power to fly around. Hence, perhaps it would not be a good idea for you.