Hi there,
Today I was maiden flying my new Skyraider Mach 2. I was using a new radio as my dx6i had already lost to many planes.I slowly exalerated the throttle on the dx8 and the Skyraider lept into the air, after trimming her out I decided to test flight performance; I roled and then sharply turned around. The plane roled over and started spyraling toward the ground. I applied full up elavator but did not provail after 4-5 spirals. I cut the throtle and quikly landed. I do not no weather thes was the dx8 or staling the wing tip. Could you please tell me what it fills like when you stall the wing from a sharp turn?

Thanks,
Patrick

Pulling elevator increases the angle of attack of the wing and brings the wing closer to tip stall if it has that characteristic. This can/should be tested for by getting very high, reducing power to 1/3 and pulling a tight loop with lots of elevator. If the plane rolls out of the loop, a tip has stalled.

If your plane indicates this behavior then caution must be used on the amount of elevator used at slower speeds. There might be some things you can do to help. First, if possible reduce your up elevator throw to simple keep from slamming in too much angle of attack. Second, if the plane has barn door ailerons with individual servos, place each on a separate channel and follow your radio instructions for programming, after which set a throttle to aileron mix so that when your throttle comes back half power, the ailerons start trimming up. At low throttle they might have 3/16 up trim. This will simulate wash out in the wing, which is an anti tip stall device and only come into play at less than half throttle so will not affect power on aerobatics.... just don't do any inverted at less than half throttle.

Last... if your plane has determined tip stall character... it must be respected. For me, the most danger is the turn from base leg to final with a cross wind blowing on the tail. Some people call it coffin corner. If a strong wind is in your face... be very cautious about slowing down on the base leg as when the turn to final is made... bad things can happen. If facing a strong wind in the face... always ask yourself, is this a tip stalling plane? If yes, then make the down wind leg twice as high as usual and give the base leg a gentler but steeper turn.

The vast majority of fixed wing airplanes can be stalled. If you continue to hold up elevator during a simple spin which is what you did the airplane will never recover and perhaps will spin even faster. The most basic recovery is to let go of that up elevator and reduce power, normally if high power remains during the spin that only serves to increase the speed of the rotation. If you do not let go of that up imput and let the airplane gain smooth airflow over the wings it will never recover from a spin.

I beleve you have simply used far to much elevator throw as indicated by AA5BY and a reduction there along with perhaps some buddy cord time in basic spins and spin recovery would do a load of good.


John

Your lucky to have saved the airplane from the death sprial....usually once the airplane has rolled over and the pilot gives lots of elevator it's done....elevator only made the sprail worse...somewhere along the line you neutraled the elevator input, stoped the roll and then pulled up using elevator again.....
My guess is that you stalled the wing period....you were in a high angle of bank then pulled elevator.....without rudder input I bet....You had a high speed stall
The Sky Raider is a gentle flyer I have never heard of it having a problem with tip stalls....
Good job saving the airplane

How did the DX6i lose many planes?

Smokin hole syndrome............comes standard in some select radios.

So I heard from someone on RCU anyway. You watch, I bet he'll pop up on here sometime telling everyone all about it.

Poor installation, no range check

I was wondering how a Dx8 would solve any connection issues compared to a Dx6i as the basic connection to the Rx is the same between radios (of course DSMX compared to DSM2 would be different).

Either way the Dx8 is just more channels and features compared to a Dx6i not a different connection protocall.

If I am wrong please someone correct me.

Thanks for the comments,
The dx6i lost two planes, first a Yak 54 on its 3rd flight, I was coming into a low fast pass when it just roled over and dug its nose into the ground! I had no input that would cause that, my thumbs were only putting in small movements, nothing to cause a crash like that!

The other crash was a Piper Cub. This was not me flying it but a man that has been flying for more than 30 years! my Dad got it on tape, you can see it just floting into a tree, he had no control what so ever, I might able to stick it on youtube if it would help?(you don't see it crash because my dad looks away at the last second but you see it going toward the tree)

We orderd a dx8 to see if that would fix the problem, We went to the flying field and got the Piper cub in the air, after taking of I found it was realy out of trim! It was rolling right so much that with full left input it was still slowly rolling right, I flicked into higher rates on eleavator so that I would have more pitch (I could hardly rotate) and aliron so that I had some roll, after about 3/4 of a lap I let all the sticks go to see how much more trim I needed after full left trim and lots of left rudder trim! At the moment my fingures got back on the sticks the cub started to spiral downwards(the same thing that happend to the Skyraider) but I did not have as much hight as I did with the Skyraider and the cub spiraled into the ground) After walking 300m we found the OS four stroke under the ground up to the fire wall! The cub had come down so hard that the os 56a was broken and would cost $100 to fix! Are cubs known to tip stall, or does this sound like a brown out?

We changed to the DX8 incase it was my DX6i impaticular, alone.

The Skyraiders elavator was set to its instruction manual, and it said that these throws were for normal flight. but it did look like alot to me; if it would help I can post some pictures of how much throw it has?

Thanks,
Patrick

Last week one of the guys at the field was flying his stick, controlled by a DX7. He hollered he didn't have it. It was coming right at the flight line at low throttle with wings level. It floated over the pavilion, past the parking lot and landed unfortunately into the front side of a knoll. Had it gone ten more feet it would have crested the knoll and landed on the back slope and probably suffered no damage.

The flight pack had obviously gone into fail save with all controls going neutral and the throttle to idle with the pilot trying until the end to recover. With the pieces back on the bench... the batteries checked fine and once turned back on, everything worked fine and it ranged checked ok. But... a few days later, it failed a range check on another airplane. It had previously had a range problem and been sent for repairs and worked ok for about three months. The owner said he will trash the transmitter... it will never be trustworthy to him again.

There is little doubt that at least three... maybe four planes were lost either due to the transmitter or something the guy was doing wrong. The stick was the only one he had fail save set on and it is repairable. The rest spun in. So... set the fail safes... at least when they go low throttle, it is a quick warning that something is amiss. and as in the case last week, damage was lessened.

I cannot speak to your problems with Spectrum other than there are none being used at our field anymore.

But I will speak to the crash you describe with the Cub. First yes of course a cub an be stalled and induce a sharp departure. Any airplane can but the Cub high aspect ratio wing much more so than other aircraft of the period.

Now the solution to this is to rig in washout at the wingtips, about two degrees. in other words the angle of attack at the wingtips will be a little less than the wing roots. This allows the wing roots to stall first and the airleron will still be functional to a much higher angle of attack.

This is very easy to do to do simply by twisting and shrinking the monocoat agine. Find an experianced modeler to help this is a very simple solution.

There are other approachs also, one being to simply rig the ailerons slightly up a few degrees when the stick is at neutral

The incident as you described it sounds like the airplane was poorly set up when you took off and it simply was very out of trim, an out of trim situation that you just could not handle and you stalled and spun agine continuing to hold up. Somewhere in there you let go of the sticks and I don,t even want to go there that can in no way help.

Your prior incident with your first radio I cannot comment on other than it sounds like a brownout situation.

John

My issue is that lots of time I see guys are blaming the radio too quickly. IMO if you are having an issue with radio A and it has not been in a crash or had the TX dropped, simply going to radio B is not going to fix the problem. Personally I think that Spektrum was marketed poorly. The whole interference is a thing of the past was very mis-leading. IMO what it did was get people to be careless with installation. I have been flying a DX7 for 4 years without a single issue. I have used the TX with an AR 9100 RX, AR 7000 and AR 6000. The commonalities is that all have a satalite RX, all were placed away from noise sources, all antennas were horizontal and 90 degrees from one another and all were run on 6V with enough capacity for the application. We seem to have lost the common rules for radio installation.

After reading Your second post...I think you're airplane was not set up correctly.....You can't just change transmitters and go fly....you need to see if control surfaces are still neutral...... your lateral balance could be off....of course that has nothing to do with a new transmitter....I say this because you need trim all one way and still can't fly straight.

Hi!
If a plane stalls you have to first check the wing for lack of wash-out! In your case it seems you had none!!
Most planes require wash-out in the wing-tips!

But...Too large elevator trows and a too far forward Cof G is also a bad thing! Check the Cof G!

Also check that neither of the wings are heavier than the other.

You should also have no play in the pushrods and flying surfaces! You should be able to push reall hard on all the flying surfaces without them flexing!

To reach that goal you must follow the simple installation rule that says: "Use as short servo arm as possible and as long elevator/aileron arm as possible"!

One's again thanks forthe comments,
Ok, I will say strate away that IMO the skyraider was set upas well as one could set up a 40 size plane. The Skyraiderhadone eneloop 6.0v battery pack with a switch and one Spektrum 4.0v pack with a different switch, the Spektrum AR6200 was rapped in foam to prevent noice and vibration getting to it. It took hours to set up ratesaccording to the manual, centre the control surfaces with sub-trim, get theC of G right accordingto the manual,ect. The PiperCub was a old planeandhad been rebuilt (Ibought it from a guy at my club)soI was not surprised that it was out of trim. Just saying, for the skyraiderthe elavatorhad 15mm of throw, rudder 20mm and aleron 6mm( I am not shore weather it is either way or not but I will check tommorow.

i have one of these planes, actualy my it's my second one, first one got retired after having the snot flown out if it, one thing is they love power, it will drop like a brick below 1/3 throttle so keep the power up at ALL times, it can even get a little squirley at 1/2 throttle

Hi!
All planes fly good! Provided they are set up right and are built light! Built light means being cautiuos to not use larger servos than necessary, or too large battery packs, and always remove wooden structure in the fuselage where such is to heavy or to much!

Why do you have 2 batteries, in a Skyraider? especially with different voltages...the extra battery is extra weight
Not being a Spektrum guy I'm not sure why the receiver was wrapped in foam....most 2.4 systems set the receiver open on a bed of foam to keep the heat down

My concern is if the RX was wrapped in foam then the antenna(s) were bent over and running paralell with the RX. Not a good place for the antenna to be. It/they need to be strait and away from the RX

Thanks,
I wraped it in foam because that is what someone at my club said to do. The satalite reiciever is not wrapped in foam, it is on the side of the plane with velcro on its back.I have to batterys in it because I wanted to make shore it was not the battery causing the problem!!
Patrick</p>

The new 2.4 receivers are all surface mount and have no crystals so a peice of velcro and a strap is all that is required. The strap should not be too tight. I like to use a small zip tie with running through some fuel tube. It is important that the antennas not be next to the RX for optimum range. Here a couple of fair examples.

You have a 6V and a 4.8V running together to power the airplane's receiver?

yes, I have a  6.0v and a 4.8v working together, why?

Thanks for the photo's</p>

When you have 2 power sources in an RC airplane going from switchs to a Y or from switchs to the receiver that is parallel circuit....for the sake of this discussion we'll say the batteries are at 6 V and 4.8V right now...out put would be 5.4V. A 6V battery is 5 cell. Consider a battery discharged at 1.1V a cell and you have 5.5V .
The other thing to consider is the internal resistance of the batteries. The 4.8V battery is a load on the 6V battery...a loads by product is heat...Batteries don't like heat.
It is always best to run the same voltage and same mAh batteries in a parallel circuit where voltage stays the same but availabe current is doubled or gives longer running times between charges. Your Skyraider is probably using standard sevos, your 6V battery at say 1000mAh would be enough for all day. Heck the 4.8 battery at 700mAh would be good for 3 to 5 flights
So 2 6V 1000mAh batteries out put would be 6V, but the available current would be 2000mAh in a parallel circuit....2000mAh means that the batteries can deliver 1mA for 2000 hours or 2000 mA for 1 hour.....
Your extra battery is not needed
Good luck