Popriv

Got alot of flying in yesterday. The turn I was working on (dont know what its called) was to make a pass over the runway, climb into a stall as I give full rudder. the plane is vertical, it stops, rotates left or right till its nose down. then I add throttle, pull up into level flight, pass over the runway and perform the same turn at the other end of the field.
The plane follows a pendulum pattern in the sky.

I could do this pretty good to the left but on the right it wasnt working as well. could have been the wind direction or the lighting?

If you can tell what I'm trying to do by my description, stall turn?, hammer head? ??? here are my questions:

As I pull up to start this turn I add throttle. as soon as I go vertical I back off on the throttle and hit full left rudder. The plate rotates and when its pointing straight down I add throttle and follow the same path as when I came into the turn....

I'm not sure when to back off the throttle and when to add full rudder. I was very inconsistant, some turns looked great others it wouldnt rotate...

Any help?

Steve

Popriv

Oh yes, I'm flying a sky raider 40 semi-symetrical high wing trainer with a TTPro .36.

AND

I just ordered my Tiger 60 kit!!!!

Steve

RCKen

My Feedback: (9)

Steve,
The maneuver you are describing is called a Stall Turn or Hammerhead, either name is correct. The problem you are having is normal. This maneuver is a pure timing maneuver, and the timing you need will be different for each plane. You are already doing the basics of the maneuver. Pull vertical and when you are ready to do the turn chop your throttle, and then add in rudder to turn the plane 180° and head on the down leg. Here is where the timing comes in. You need to put the rudder in before the plane stops moving. This maneuver requires air flowing over the rudder for it to work. If you wait too long to add in rudder there is no air flowing over the rudder to turn the plane, and the plane will just "flop" over. If you add it in too soon there will be too much air over the rudder and you will force the plane around which will throw it out of the line of the maneuver. So what you need to do is practice your timing as to when you add rudder in. As I said, it's different for each plane. Sometimes if you wait too long to add rudder you can "blip" the throttle to get a bit of air over the rudder to perform the maneuver.

Bear in mind here, some planes are better for this maneuver than others. Usually planes with bigger rudder surfaces will perform better in this one.

The best advice here is to just keep trying until you hit the timing for the maneuver. And then when you find it..... practice, practice, practice. This is one of my favorite maneuvers, and when it's performed properly it looks sooooooo good.

Ken

Jetdesign

My Feedback: (8)

It is easiest to do a stall turn into the wind. Having a lot of rudder throw helps - if you are comfortable flying around and using lots of rudder, try mechanically adjusting for a little more throw. Trainers tend to have very small rudders which doesn't aid in aerobatics.

Popriv

I think I will add more throw to the rudder and put it on dual rates...

Steve

MajorTomski

Well first the airplane has absolutely no idea that the wind is blowing or which direction it is blowning from.

you should leave the power on as you do the turn, so that the propwash can help the rudder do its thing. If done properly the plane appears to pivot about its center of gravity If you're still going too fast on the up line then the plane will fly around a wingtip.

The plane will also turn better one way than the other due to P factor.

smithcreek

My Feedback: (25)

You also don't need to kill the throttle, you only need to pull it back. Keep going up until the plane is on the verge of a stall then rudder. This way you still have air going over the rudder.

jetmech05

the aircraft should Hammerhead easier to the left than to the right......bump throttle as you add left rudder...don't bump throttle if your turning right....a tad more speed with power off to turn right at the top of the hammerhead...

bruce88123

He is absolutely correct on this. I get so tired of people saying that a plane does this or that better into the wind or away from the wind than vice versa when in fact the plane couldn't care less as it doesnt know there is any wind. Does the wind have an effect? Sure! It blows the plane across the ground and the pilot fails to compensate for this and then blames the wind for HIS poor flying. It doesn't like turbulence either. Even in full scale aerobatics the pilot has to compensate for the effects of the wind on his flight path. You need to modify the pitch or bank constantly to correct the flight path RELATIVE to the ground observer. To climb straight up you will seldom be pointed straight straight up but rather 85 or 95 degrees to the ground and maybe some yaw to allow for crosswind.

tIANci

Ask any F3A pilot and you will know they tend to stall turn INTO the wind. Why? Because to turn with the wind will make you lose some control in the manuever, it does not look as good for sure. Sorry if it sounds a little harsh but maybe its time we consider what we say.

Also, when executing a proper stall turn you DO NOT put on the throttle. You may blip it a bit to get some wash over the rudder as your plane has a small rudder but not put the power on, if you do that you see something like a U turn and not a stall turn. You need to enter the maneuver with your wings level too if not she comes over in all sorts ... do try to turn her before the plane wants to slide backwards, if that happens she looks bad too. As for the rudder, don't release it too early, if you do so you will see the tail wag, I hold it for almost a plane's length on the downline.

Have fun practising.

Montague

This is true in a steady state, but in this case, wind direction DOES matter because we aren't in a steady state.

Two reasons. First, if you are correcting with rudder during the upline, the plane will be yawed into the wind. This means the CG of the plane is now offset to the side of the rudder. This means that the plane will naturally fall off to the upwind side. If you want to rotate the nose "downwind", you have to move the CG back to vertical and keep going. This takes much more rudder authority to move the CG "up hill" and around.

Second, as the plane slows, the vectors are changing, so the direction of the relitive wind over the tail is changing. Assume a 5mph crosswind, and you start the vertical climb going 50mph. Now, as the plane slows to nearl stopped, say 5mph, the airflow that was nearly in line with the fuse is now coming in at a 45degree angle. On a plane with a large vertical stab (as many sport planes have), the plane will naturally yaw into the wind if the pilot makes no correction. If you want to keep the nose pointed straight up, you'll find you need opposite rudder.

You generally don't want to worry about the nose pointing striaght up, let the plane yaw a little, and focus on getting the plane to climb with out drifting downwind too much, and let that little yaw before the top help pull the plane around by going with it when you apply rudder instead of fighting against it.

Another couple of tips. I find that on many planes it helps to chop the power quickly rather than slowly decrease it. The reason seems to be that as the plane slows, you loose control authority in pitch, roll, and yaw. So the more time you spend slowing down, the more time you have for the plane to "flop" or do something you don't want. A quick chop gets the plane to slow faster.

After I pull the power all the way to idle, I then bring it back up a few clicks and leave it there. Some guys like a quick burst of power to get air over the tail, but I find that a quick burst often creates problems with torque reactions to the motor. So rather than a quick burst of power, I leave in just a little power to get enough airflow over the tail. It's a bit more complicated, but to sum up, I find I get the most consistant hammers when I:
- full power
- pull vertical (use some rudder to stay straight)
- climb a bit with full power
- quickly pull power all the way to idle
- wait for a moment for the plane to slow
- a few clicks up on power
- wait, watch to see if the plane is trying to go one way or the other
- full rudder "with" the airplane.

YMMV, have fun playing around with it.

Lnewqban

Steve:

Check these links:

http://www.masportaviator.com/ah.asp...&ID=30&index=1

http://www.troybuiltmodels.com/newsi...ce.html#hammer

http://www.scootworks.com/rdrc/

Regards!

Popriv

All good stuff!

I cant wait to get out there saturday and try it out.

thanks

Steve

Tom Nied

28 for a high on Saturday? Don't think I could convince myself to go out flying in that cold. But do agree I wish I could go out and practice some Stall Turns. I am by no way an expert but have noticed when trying them, that timing is important. You kind of get a rhythm going and its all dependant on the particular airplane. Wonderful maneuver to learn. I even enjoying doing the bad ones, you learn from them.

Popriv

Might make the 40's on Saturday..
Last saturday was 30 but very little wind so it wasnt bad... I flew from 9:00am to about 1:00pm almost non stop.
I've only been flying 6 months so the addiction is still fresh and new.
I need the fix! more air time....
I'm curious to see how cold/windy is to much....


Steve