PDA

View Full Version : Avoiding spin in p47



deskpilot
08-04-2009, 03:37 PM
Thinking I'd best avod turning I've been trying to climb, half roll then come back down (there's a fancy name for this maneuover i'm sure) but I find sometimes that I stall or spin when I'm pulling out of the inverted position.
Is this just caused by too low speed or could trim be an issue?

danjama
08-04-2009, 03:47 PM
Got Track?

idonno
08-04-2009, 03:51 PM
You are either too slow (causing a normal stall), or pulling to hard on the stick (causing an accelerated stall).

Some people may try to tell you that it's trim. DON'T LISTEN TO THEM. There is a great deal of misunderstanding around here about trim. The only thing trim does is relieve you from having the hold pressure on the stick or rudder peddles. It's probably true that you are not in coordinated flight (with the ball in the slip indicator centered) when you enter the stall, hence the spin, but when you are rapidly changing airspeed you use rudder to keep the airplane in coordinated flight, not trim.

deskpilot
08-04-2009, 05:05 PM
Thanks Idonno, that's helpful. I've heard people talking about keeping the ball centred but there seems to be so much to think about I haven't really concentrated on that. I can see I need to , and the advice re trim is helpful. i'll try and keep the speed up more before I pull that manoever

SILVERFISH1992
08-04-2009, 05:24 PM
There is an easy way to avoid this.....Dont fly the P-47 if your not up to the challange.


Thats why I dont fly the P-47 becuase it is inferior to my TnB infested needs.

idonno
08-04-2009, 05:32 PM
Originally posted by SILVERFISH1992:
There is an easy way to avoid this.....Dont fly the P-47 if your not up to the challange.


Now there's a motto for life; if at first you don't succeed, give up. http://forums.ubi.com/images/smilies/clap.gif

SILVERFISH1992
08-04-2009, 05:35 PM
http://forums.ubi.com/images/smilies/shady.gif

I'm Logging off for now.

SILVERFISH1992
08-04-2009, 05:39 PM
I'm back!!! http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

idonno
08-04-2009, 05:42 PM
lol!

mortoma
08-04-2009, 06:47 PM
I think the P-47 has a nice high speed turn. But no, at the apex of a steep zoom climb where you invert to come back down, you'd have to keep her above 240kph and be careful to not start a stall. If you let her get down to less than 200kph you might even start a tail slide before you even can get inverted. Then you have no choice but to go for a hammerhead but your rudder effectiveness will be a tad too low for that.

I use that maneuver a lot in a lot of different planes and you have to have a feel for it. That maneuver is particularly useful in attacking bombers and due to the vertical nature, you avoid much of the defensive gunner's fire. Or at least minimize your chances of not getting hit. And you can fire at them on the return trip up too. This tactic against fighters in the P-47 such as either the Bf or the FW might not be such a great idea because they can do this maneuver as well or better than you if they get in sync with you, especially the Bf. But if they are at the bottom when you're at the top then it can be effective as long as you can get stabilized for a shot.

M_Gunz
08-04-2009, 07:26 PM
Originally posted by deskpilot:
Thanks Idonno, that's helpful. I've heard people talking about keeping the ball centred but there seems to be so much to think about I haven't really concentrated on that. I can see I need to , and the advice re trim is helpful. i'll try and keep the speed up more before I pull that manoever

Ball much off center = extra drag.
Ball off center more than a little when you stall = spin.
Ball off center when you shoot = bullets don't go where you aimed.

Hah, why worry bout dat ball! http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

danjama
08-04-2009, 07:47 PM
Practice centering the ball in level flight, to start to understand it.

PanzerAce
08-04-2009, 08:18 PM
Originally posted by mortoma:
I think the P-47 has a nice high speed turn. But no, at the apex of a steep zoom climb where you invert to come back down, you'd have to keep her above 240kph and be careful to not start a stall. If you let her get down to less than 200kph you might even start a tail slide before you even can get inverted. Then you have no choice but to go for a hammerhead but your rudder effectiveness will be a tad too low for that.

I use that maneuver a lot in a lot of different planes and you have to have a feel for it. That maneuver is particularly useful in attacking bombers and due to the vertical nature, you avoid much of the defensive gunner's fire. Or at least minimize your chances of not getting hit. And you can fire at them on the return trip up too. This tactic against fighters in the P-47 such as either the Bf or the FW might not be such a great idea because they can do this maneuver as well or better than you if they get in sync with you, especially the Bf. But if they are at the bottom when you're at the top then it can be effective as long as you can get stabilized for a shot.

Interesting, I actually find the -47 to be the easiest plane for me to hammerhead with,. I generally start going over at like 130ish....

Ba5tard5word
08-04-2009, 08:34 PM
Go try flying a Corsair or an I-16 and you'll get used to the warning signs before a speed-stall that makes your plane flip over.

A lot of planes do it--Spitfire, Fw-190, etc. The I-16 is terrible at it and the P-39 will spin out of control half the time when you do a speed stall.

You just have to get a feel for it and what you can push your plane to do. I never keep my eye on the slipball but with experience I know what each plane can do before flipping. Be gentler with the stick, don't pull hard when your plane starts to veer a bit in maneuvers, etc.

M_Gunz
08-04-2009, 09:06 PM
Originally posted by PanzerAce:
Interesting, I actually find the -47 to be the easiest plane for me to hammerhead with,. I generally start going over at like 130ish....

130 kph or mph? I am pretty sure that for a true hammerhead you come to a stop and kick the tail against the propwash.

It's smarter to do a wingover or half loop. You have some speed to maneuver with if necessary and don't present a still
target.

mortoma
08-04-2009, 09:27 PM
Originally posted by PanzerAce:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by mortoma:
I think the P-47 has a nice high speed turn. But no, at the apex of a steep zoom climb where you invert to come back down, you'd have to keep her above 240kph and be careful to not start a stall. If you let her get down to less than 200kph you might even start a tail slide before you even can get inverted. Then you have no choice but to go for a hammerhead but your rudder effectiveness will be a tad too low for that.

I use that maneuver a lot in a lot of different planes and you have to have a feel for it. That maneuver is particularly useful in attacking bombers and due to the vertical nature, you avoid much of the defensive gunner's fire. Or at least minimize your chances of not getting hit. And you can fire at them on the return trip up too. This tactic against fighters in the P-47 such as either the Bf or the FW might not be such a great idea because they can do this maneuver as well or better than you if they get in sync with you, especially the Bf. But if they are at the bottom when you're at the top then it can be effective as long as you can get stabilized for a shot.

Interesting, I actually find the -47 to be the easiest plane for me to hammerhead with,. I generally start going over at like 130ish.... </div></BLOCKQUOTE>Maybe, I admit it's been a while since I have messed with the Jug.

BillSwagger
08-04-2009, 10:25 PM
Originally posted by deskpilot:
Thinking I'd best avod turning I've been trying to climb, half roll then come back down (there's a fancy name for this maneuover i'm sure) but I find sometimes that I stall or spin when I'm pulling out of the inverted position.
Is this just caused by too low speed or could trim be an issue?

could be trim if you are trimmed tail heavy, (the nose goes up on its own) so it doesn't take much stick force to put it into a stall.
If you have level trim into the maneuver then
its too much stick force. In the middle of a maneuver it can help to deploy combat flaps if the maneuver requires lower airspeed.

K_Freddie
08-05-2009, 02:41 AM
At the top of your vertical, you might find that you do not have enough speed to roll over...

As you approach zero speed you can use the propwash (via rudder) to flip the nose over.
Try to remember that whichever wing is hardly moving through the air, will be the first to stall. To counter this you might have adjust the amount of rudder you apply.


On reaching zero speed, to keep control, reduce you throttle to zero, otherwise the engine torque (that's a big engine up front) will twist your plane into a stall, more than propwash - this would be more pronounced if you slide backwards.

If sliding backwards, you must reverse your controls as you're now flying backwards. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

M_Gunz
08-05-2009, 04:56 AM
How do you stall a vertical plane? The wings should be at zero AoA and making NO lift so how do you stall?
If you idle the throttle then WHAT propwash?


Hammerhead; Stall Turn
Hammerhead; Stall Turn 1/4 loop (pull or push) to vertical, as momentum/airspeed decreases, rudder is applied and the aircraft rotates around its yaw axis, the nose falls through the horizon and points towards the ground, a momentary pause is made to draw the vertical down line, and 1/4 loop to level flight. This figure is sometimes called a stall turn which is a misnomer because the aircraft never actually stalls. The manoeuvre is performed when the aeroplane decelerates through 20 - 30kts (more or less, depending on the aeroplane flown) of airspeed. The cartwheel portion of the hammerhead is performed with full rudder and full opposite aileron. Gyroscopic forces from the propeller during the rapid rate of yaw will produce a pitching and rolling moment and a degree of forward stick will be required to keep the aeroplane from coming off-line over the top. The yaw is stopped with opposite rudder while the ailerons and elevator remain in position, then once the yaw is stopped and the aeroplane is pointed down vertically, all controls are returned to neutral together. Although they can be flown left or right in any aeroplane with the proper technique, a hammerhead is best flown to the left with a clockwise rotating prop, and to the right with an anticlockwise rotating prop (as in a Yakovlev type), due to propeller torque/gyroscopic effects.

AndyJWest
08-05-2009, 05:42 AM
I may be missing something obvious here, but it seems to me that neither a stall turn nor a hammerhead turn is a sensible move for a P-47 to pull in combat. Heading upwards at slow speed in an almost vertical climb will make you a sitting duck, surely? Even if you pull such manoeuvres off, you will be initially in the slow-speed, High-AOA, high-drag section of the P-47 flight envelope, unless you continue in a steep dive, and if that was your intention, why not maintain speed and dive right off?

If you go back to deskpilot's original posting, he says he wants to 'climb, half roll then come back down' to avoid turning. To me it sounds like he is merely substituting a turn in the vertical plane for one in the horizontal, to no real benefit. As I understand it, to make a rapid 180 degree turn with the least loss of energy, you should do a climbing turn if you are above corner speed, or a diving one if below it(our old friend the yo-yo). Any manoeuvre that drops you below corner speed is wasting energy.

All this is hypothetical, of course. In combat you need to be able to do the unexpected, and a 'perfect' energy pilot will be more predictable than a rookie: perhaps there's hope for us noobs yet...

M_Gunz
08-05-2009, 07:22 AM
Originally posted by AndyJWest:
I may be missing something obvious here, but it seems to me that neither a stall turn nor a hammerhead turn is a sensible move for a P-47 to pull in combat. Heading upwards at slow speed in an almost vertical climb will make you a sitting duck, surely?

Exactly! It's an airshow maneuver but then not all airshow maneuvers are bad for combat, wingover for example.


Even if you pull such manoeuvres off, you will be initially in the slow-speed, High-AOA, high-drag section of the P-47 flight envelope, unless you continue in a steep dive, and if that was your intention, why not maintain speed and dive right off?

You should not be at high AoA running up or down vertical. You should be at zero AoA, making no lift as that would tear
you off the vertical path. Slow and level, then you are at high AoA, slow and most any lift situation you are but not
when you are on a more or less ballistic (like a thrown stone) path. At least not on purpose.


If you go back to deskpilot's original posting, he says he wants to 'climb, half roll then come back down' to avoid turning. To me it sounds like he is merely substituting a turn in the vertical plane for one in the horizontal, to no real benefit.

It depends on what he's describing, it seems to fit vertical turning using roll to me. It has plenty of benefit if he is
doing a wingover or looping over the top, much as you describe below. It stores energy while slowing him down to where he
can make a tight reversal and then he gets his speed back in the dive. The half roll part is just to re-orient onto a new
direction to exit but if you keep your speed then loop or turn over the top, what's the difference?
In the Red Bull air races I've watched the contestants do that except just looping over the top, one pulled over 9 G's at
the top, it's done to save seconds in the course reversal where they have to go back through the pylons. None of them do a
flat turn at that point (plenty going down the course and back but not where they 180 to go back through the opposite way)
or anything but vertical since that scrubs speed the fastest. They are going about 240 mph at the bottom and those aerobatics
planes turn tightest at much lower speed. If you've never seen them then here's a Youtube link. (http://www.youtube.com/watch?v=ntVBN0W3fpA)


As I understand it, to make a rapid 180 degree turn with the least loss of energy, you should do a climbing turn if you are above corner speed, or a diving one if below it(our old friend the yo-yo). Any manoeuvre that drops you below corner speed is wasting energy.

I'm not sure about that last part but it sure turns you the fastest with the least loss. You can lose less in a slower turn
but that might ruin your whole day too. I guess it depends on what you call corner speed. Is that instantaneous corner that
your plane cannot maintain without losing alt or is it sustained corner or is it maneuver speed, the fastest you can go and
still pull full stick on one axis? All of those have been called corner speed on different net forums for different games
since over 10 years back.


All this is hypothetical, of course. In combat you need to be able to do the unexpected, and a 'perfect' energy pilot will be more predictable than a rookie: perhaps there's hope for us noobs yet...

I've heard WWII surviving pilots say exactly that, they would fly with a little bit of slip and do other imperfect things
just because it made them harder to predict and hit. But if you really need to build an energy advantage then fly clean
at least when no one has a real chance of shooting you, just never in a straight line for long.

deskpilot
08-05-2009, 09:35 AM
My question has generated some interesting and informative comments, thanks! For the record,
all I was actually trying to do in my probably erroneous way was turn 180 degrees to face the enemy planes who I have just crosed with. I understood that to just turn 180 degrees would lose me too much energy so I was thinking that turning more in the vertical would be preferable, but I was sometimes stalling or spinning when doing this. The plane i've most experience of is the Yak 3 so adapting to the p47 is quite a challenge. i think some basic flying practice is required. M Gunz comments on keeping the ball centred I will try to follow. Maybe I would be advised to stick with the Yak until I'm better at that but there are so many planes to try in IL2!

MD_Titus
08-05-2009, 12:44 PM
Originally posted by idonno:
You are either too slow (causing a normal stall), or pulling to hard on the stick (causing an accelerated stall).

Some people may try to tell you that it's trim. DON'T LISTEN TO THEM. There is a great deal of misunderstanding around here about trim. The only thing trim does is relieve you from having the hold pressure on the stick or rudder peddles. It's probably true that you are not in coordinated flight (with the ball in the slip indicator centered) when you enter the stall, hence the spin, but when you are rapidly changing airspeed you use rudder to keep the airplane in coordinated flight, not trim.
but if the rudder trim is out of whack then it can contributel.

MD_Titus
08-05-2009, 12:49 PM
Originally posted by BillSwagger:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by deskpilot:
Thinking I'd best avod turning I've been trying to climb, half roll then come back down (there's a fancy name for this maneuover i'm sure) but I find sometimes that I stall or spin when I'm pulling out of the inverted position.
Is this just caused by too low speed or could trim be an issue?

could be trim if you are trimmed tail heavy, (the nose goes up on its own) so it doesn't take much stick force to put it into a stall. In the middle of a maneuver it can help to deploy combat flaps if the maneuver requires lower airspeed. </div></BLOCKQUOTE>

utterly wrong

BillSwagger
08-05-2009, 01:41 PM
well its not the trim alone. But being trimmed tail heavy means it wouldn't take much stick force to put it into a spin at lower speeds.
this is if i understand the maneuver correctly.


on the topic of trims, here's a trim turn.
I use nothing but trim to nose up and turn the plane.

http://www.filefront.com/14201993/trimturn.ntrk

M_Gunz
08-05-2009, 02:17 PM
Originally posted by deskpilot:
My question has generated some interesting and informative comments, thanks! For the record,
all I was actually trying to do in my probably erroneous way was turn 180 degrees to face the enemy planes who I have just crosed with. I understood that to just turn 180 degrees would lose me too much energy so I was thinking that turning more in the vertical would be preferable,

And that is correct most of the time, depending on conditions mostly your speed.


but I was sometimes stalling or spinning when doing this.

You don't have to go straight up, just do a turn on a tilt after you've slowed some but don't get below 360 kph starting
the turn and in the P-47 don't pull hard.

Chances are you're running around jumping into fights at too low a speed. You might better put the nose into a shallow dive
and run instead until you've built up to over 300 mph (500 kph), well over maybe and then do your pure vertical reversal.

BillSwagger
08-05-2009, 02:25 PM
Originally posted by BillSwagger:
well its not the trim alone. But being trimmed tail heavy means it wouldn't take much stick force to put it into a spin at lower speeds.
this is if i understand the maneuver correctly.


on the topic of trims, here's a trim turn.
I use nothing but trim to nose up and turn the plane.

http://www.filefront.com/14201993/trimturn.ntrk

i might also add i've been banned for this on one server, with out warning and i have no way to contest it.
It isn't a mod, it is standard 4.08, and every plane with trim is capable.

M_Gunz
08-05-2009, 02:47 PM
Originally posted by idonno:
Some people may try to tell you that it's trim. DON'T LISTEN TO THEM. There is a great deal of misunderstanding around here about trim. The only thing trim does is relieve you from having the hold pressure on the stick or rudder peddles.

Depending on how your stick sliders especially pitch is set, if you have lower in center and higher at the outside it
is a definite advantage to keep trimmed so you don't pull much stick at all most of the time. You will go faster the
better you are trimmed since as Oleg stated in answer about this in 2002 no one can hold a joystick absolutely steady,
tiny stick wobble causes drag.

It's a control problem. With the sliders set so that the more you pull back, the more % the pull counts you have a
situation where a small move near center counts for so much and the same small move farther back counts for more and
more. Result is less fine ability to control the plane before even half pull. Staying trimmed to near the speed you
are running keeps you able to have finer control at least for steady maneuver. Over-trim.. bad for control when you
finish whatever maneuver unless that very maneuver has robbed speed to where the plane is no longer over-trimmed.

All you have to do is try practice holding aim with the plane out of trim to see this. Pick a friendly at 200m
and keep the crosshairs right on him while out of trim enough you need to hold 1/3rd stick or more. Go ahead!

Trim for speed. If the turn will leave you slower then keep adding nose-up in the turn but not more than for the
speed you will come out of the turn with, or somewhere near that. If you will be changing speed a lot then it's
better to neutralize trim and get on with it until you stabilize your speed for a while. It takes practice just
to get to where you usually wind up in the ballpark or even automatically start trimming as your speed changes.

One biggie is coming up behind a target, slowing down and then the nose wants to bob when you aim because A) you
didn't trim for the slow down and B) your own corrections lag events and induce oscillations (PIO) that you are
trying to stop.
My answer is don't slow down but that involves learning to shoot at longer ranges....

deskpilot
08-05-2009, 03:04 PM
Your replies to my post have been very helpful.
thanks.
I think I need to keep practicing the basics of turning, diving, aiming etc as I still have alot to learn!