Steering on final with rudder

[Peter Collins]

Yeah, put me down as ignorant. What are called 'primary' and 'secondary' effects seem to me to be matters of convention rather than fundamental physics. If 'bottom rudder' is bad, why isn't 'top rudder' good? I've just been told that a wing drop stall won't spin you if you are balanced. But the wing drop pushes the ball out so I'd expect you'd need to apply bottom rudder to keep the ball centred, because (if I've got this right) one aspect of the wing-drop stall is that the inner aileron has lost lift effectiveness (and got a whole heap draggier). Yes, lower the nose, and surely, now we are in a spiral? Sure, that's not a spin, so I guess the advice is correct - but is it merely an alternative way to crash? I certainly wouldn't want to use ailerons alone to roll out of the spiral, due to adverse yaw, but rudder will deal with that aileron problem, and could even roll you out, without the ailerons, not so?

 

And flaps do indeed control pitch and some of us have been taught that we should use them to give better visibility in some situations, and that one of the problems in the flapless landing can be it's so much harder to see everything. I dunno - it's an instructor thing, I guess.

 

 

[Ultralights]

Recover from a stall, first thing should be unstall the wing, release back pressure, enough to reduce AOA 1 or 2 deg will unstall the wing, all the while keeping balanced with rudder, if a wing drops, still, unstall the wing first, once unstalled everything works as normal, aileron, rudder etc, The use of rudder to "pick up a wing drop" should read more like, use rudder to stop the wing drop after the wing has unstalled, if it's unstalled by 1 or 2 degrees there's a risk the effective increase in AOA by the aileron could cause a stall of the wing with the down going aileron.

 

In a spiral dive, the wings are still flying, so use aileron to roll level, then recover from the dive with elevator, in a spin, the wings are stalled, hence aileron will not help the situation.

 

When near or very close to stall, rudder for balance only.

 

This is what can happen when using rudder instead of aileron to initiate a roll when slow and close to stall AOA. This pilot overshot the turn to final, and used rudder to tighten up the turn

 

 

 

[motzartmerv]

And flaps do indeed control pitch and some of us have been taught that we should use them to give better visibility in some situations,

yoju miss the point. Yes, the flap can change the attitude of the aeroplane, but do you use it to control the attitdue? Do you lower and raise flap to hold the nose in the cruise attitude? or the clim attitude? No, you dont. The same applies to the rudder, its there to co ordinate the turns WITH aileron. It provides control about the normal or vertical axis. nothing more, it isnt used to control roll.

 

 

[facthunter]

Spirals and spins must be correctly identified. The procedure works for VF or IF conditions.

 

Spiral ...Aircraft is turning (Yaw)..airspeed is increasing and "G" load increasing ROD increasing. Cure .... Level wings with ailerons as quickly as possible and recover from ensuing dive with due regard to aircraft loads imposed by high speed (Vne,) and height available.

 

Spin Aircraft yawing but speed fairly slow and not increasing and NOT a large "G" load. Aircraft is stalled and spinning. (Autorotating) main method of recovery is to arrest turn with rudder (Full opposite) and a varying technique of stick forward movement. Centre controls when turn needle centres and recover normal flight.

 

Some aircraft have a lot of adverse yaw with aileron application. The extra drag opposes the turn desired . Roll is always a further effect of yaw unless the aircraft is designed to behave otherwise. I wouldn't get too worked up about it. Know your aeroplane, and know what it is doing at any time. Spiral recovery training is not recommended in many RAAus planes, particularly the Skyfox group. Nev

 

 

[turboplanner]

Recover from a stall, first thing should be unstall the wing, release back pressure, enough to reduce AOA 1 or 2 deg will unstall the wing, all the while keeping balanced with rudder, if a wing drops, still, unstall the wing first, once unstalled everything works as normal, aileron, rudder etc, The use of rudder to "pick up a wing drop" should read more like, use rudder to stop the wing drop after the wing has unstalled, if it's unstalled by 1 or 2 degrees there's a risk the effective increase in AOA by the aileron could cause a stall of the wing with the down going aileron.In a spiral dive, the wings are still flying, so use aileron to roll level, then recover from the dive with elevator, in a spin, the wings are stalled, hence aileron will not help the situation.

 

When near or very close to stall, rudder for balance only.

 

This is what can happen when using rudder instead of aileron to initiate a roll when slow and close to stall AOA. This pilot overshot the turn to final, and used rudder to tighten up the turn

 

Notice how very fast things went wrong; there was no subconscious reaction from the pilot. Very graphic lesson in this video!

 

 

[facthunter]

It certainly does go out of shape very quickly. Any successful recovery action would have to be instant and very positive and if the nose was down very far it wouldn't work anyhow. Twins like these have a fair bit of stuff along the wing in engines etc and are hard to stop a yaw once started due the mass along the wing having a large inertia effect. . Nev

 

 

[aro]

I've just been told that a wing drop stall won't spin you if you are balanced. But the wing drop pushes the ball out so I'd expect you'd need to apply bottom rudder to keep the ball centred, because (if I've got this right) one aspect of the wing-drop stall is that the inner aileron has lost lift effectiveness (and got a whole heap draggier). Yes, lower the nose, and surely, now we are in a spiral? Sure, that's not a spin, so I guess the advice is correct - but is it merely an alternative way to crash? I certainly wouldn't want to use ailerons alone to roll out of the spiral, due to adverse yaw, but rudder will deal with that aileron problem, and could even roll you out, without the ailerons, not so?

To deliberately spin an aircraft, you use rudder to yaw the aircraft at the point of (and after) stall. Aileron might aggravate the spin in some aircraft, but the primary control turning a stall into a spin is the rudder. To roll an aircraft using rudder you are yawing the aircraft so that one wing is at a greater angle of attack than the other due to dihedral etc. This increases the likelihood that one wing will stall before the other, causing a wing drop or spin.

 

Using the rudder for roll, particularly close to the stall, makes it MORE likely that you will spin, not less.

 

After the stall (with or without wing drop) you use the rudder to PREVENT or reduce yaw - not to pick up a wing with additional yaw. If a wing drops you may well be uncoordinated, but after the stall it isn't really relevant - the actions are: prevent yaw (e.g. caused by the wing drop) with rudder, unstall the wing by reducing angle of attack (elevator), then you can roll the aircraft level using aileron as normal.

 

Adverse yaw isn't a reason not to use aileron. It is a natural consequence of increasing the lift on the down aileron - additional lift means additional drag. you counter that with rudder - that's what it is there for.

 

The rudder is not intended to be a steering control in the air. It is there to keep the tail directly behind the nose with the varying forces from aileron adverse yaw, and slipstream changes with different power settings.

 

 

[Teckair]

What about those with tail wheels?Regards

Keith Page

Same deal.

 

 

[Teckair]

This is a topic close to my heart as my profession is training. So this may sound critical of instructors, but my aim is to help instructors. So your job is not to critique until the later stages, your job is to help them make faster and better decisions, until they have a better mental picture of the many types of landing scenarios and until thier own decision making can keep up with the aircraft. And the most effective way to do this is to talk them thru it slightly in advance. The exact technique a dance instructor uses.

And some wonder why the instructors section is not available to everybody?

 

 

[pmccarthy]

Despite the varying opinions this discussion has reinforced for me the need to be very careful and balanced with manoeuvres near the ground, including turning final and any emergency management. I am still unsure about side slipping. I was taught to do it, and have done it for years to adjust rate of descent, but have been told by some instructors that it is dangerous and a bad practice.

 

 

[DrZoos]

Peter its a debatable item at best.

 

Despite the varying opinions this discussion has reinforced for me the need to be very careful and balanced with manoeuvres near the ground, including turning final and any emergency management. I am still unsure about side slipping. I was taught to do it, and have done it for years to adjust rate of descent, but have been told by some instructors that it is dangerous and a bad practice.

Side slipping is not dangerous enough to make a generalization that its dangerous. . Yes its pro spin controls but as long as you keep the nose down and thus your airspeed up its not dangerous. And any instructor tellying you it is is full of rubbish. You need to check you POH about side slipping in your plane and its best to practice it initially and test your palne with plenty of altitude. But to generalise and say its dangerous is very very poor advice in my opinion. I side slip all the time when im practicing forced landings which is one of my favourite things to do. I was told too it was dangerous in low wings. So me and my former instructor went out climbed to 5000 and put it through its paces. Not a worry in the world the control surfaces behaved exactly as expected and im now a very confident side slipper. Which is one trick i will be glad to have if i ever do have a real engine out. As it allows me to turn an otherwise tricky overshoot into almost an undershoot if need be.

 

 

[2tonne]

For crosswind landings, I understand the standard techniques are i) crab/ de-crab or ii) sideslip (wing down into wind and opposite rudder) or a combination of both. In both of these techniques, are you not ultimately using rudder to align the nose of the aircraft with the runway (i.e., steering with rudder on final)? I am not talking about making turns using the rudder (as I would always make coordinated turns with aileron and rudder in the circuit), but is seems use of rudder on final to align with the runway is normal practice...mind you I am often wrong about things...

 

 

[motzartmerv]

. Yes its pro spin controls but as long as you keep the nose down and thus your airspeed up its not dangerous.

I seriously worry sometimes. The information that gets shared in these discussions has potential to do some serious damage, or at least, undermine what we as instructors spend so much time and effort trying to install.

 

Side slipping is NOT pro spin. It is actually ANTI spin.

 

The sideslip is a normal manourvre and is actually part of the RAA training syllabus (section 3.04) and therefopr MUST be demostrated for certificate issue. You even need to demonstrate a slipping turn of 90 deg's.

 

Some aircraft (low wings) with selectable fuel tanks MAy have problems with uncovering fuel intakes. But any POH will spell this danger out.

 

 

[facthunter]

Sideslips are not dangerous if you know what you are doing. They are more suited to basic planes and some do it better than others. Done at excessive airspeed they are not tidy and strain the aircraft and are not as effective at getting a steep approach without increasing speed. Precise speed control in a sideslip is critical and needs to be mastered. Learn from someone who can actually do them and practice solo at height before being confident lower down

 

I could count on one hand the people I have encountered lately who want to do them let alone know how. Any no brain can do some kind of beat up, where they would be much better occupied learning to fly an aeroplane properly. IF the plane has really effective flaps or spoilers the technique is probably not necessary, but nonetheless it is a good thing for your flying knowledgebase, and general handling capability. Nev

 

 

[octave]

I certainly had do demonstrate side slips during my test and also during my BFRs apart from being a very useful technique (especially in a forced landing) it is also fun.

 

Side slipping is NOT pro spin. It is actually ANTI spin.

I was hoping someone (with more credentials than me) would make this point.

 

 

[aro]

For crosswind landings, I understand the standard techniques are i) crab/ de-crab or ii) sideslip (wing down into wind and opposite rudder) or a combination of both. In both of these techniques, are you not ultimately using rudder to align the nose of the aircraft with the runway (i.e., steering with rudder on final)? I am not talking about making turns using the rudder (as I would always make coordinated turns with aileron and rudder in the circuit), but is seems use of rudder on final to align with the runway is normal practice...mind you I am often wrong about things...

Absolutely. Again the rudder is being used to keep the tail directly behind the nose, except that in this case it is relative to the direction of travel over the ground instead of through the air.

 

I don't really see the crab or sideslip as different crosswind methods - more a difference in how early you align the aircraft with the runway. Not even the most ardent proponent of the sideslip method would be slipping on a 5 mile final for a straight in approach - they will crab, then at some point align the aircraft with the runway. Once you align the aircraft with the runway you need to lower the wing to avid drift - unless you do it so late that drift doesn't develop before you touch down, which is only really applicable if there are reasons you can't lower a wing in the flare.

 

 

[facthunter]

A sideslip is done when the aircraft is banked first and the tendency to weathercock is stopped by opposing with rudder. The elevator controls the pitch and speed in the normal way. The engine is at idle as you are GENERALLY trying to get the plane down steeper.. The controls are CROSSED in the way generally appreciated. IF you pull the stick back the top wing will stall first, and the plane will roll over the high side and probably spin if the stick is held back. It is not the most direct way to enter a spin and there is more time to avoid it but again you MUST know what is going on. Nev

 

 

[turboplanner]

Now and again this forum drifts into "learning to fly by correspondence", and that's the most dangerous way to learn to fly.

 

A good instructor is a good instructor.

 

A lot of posts which seem wrong can simply be the poster's inexperience at clear communication, or your misinterpretation of a word or phrase.

 

Much better to ask your instructor about physical techniques which require physical demonstration.

 

Have a look at that twin going in again, and ask yourself:

 

"Do I fully understand the physical dynamics, and the delicacy of touch required?"

 

"In a slight overshoot on final, what would I be likely to do controlwise"

 

"If I just happened to hit a windshear at the point of turn, would I know how to recover from the out of balance situation?

 

We don't know what the instructors were arguing about anyway; it could have related to the last 10 metres of flight before the touchdown.

 

Doesn't say much for them that they let so much bullsh$t be written on this thread without stepping in.

 

 

[Tomo]

Ah, the old lead with rudder debate has arisen once again!

 

 

 

[motzartmerv]

Tubz, we have to let discussion take its course, but I do draw the line at downright WRONG info being propagated.

 

i agree that learning by correspondance is a very unsafe way to go, and would hope that we try to avoid it as far as practical.

 

 

[Head in the clouds]

I seriously worry sometimes. The information that gets shared in these discussions has potential to do some serious damage, or at least, undermine what we as instructors spend so much time and effort trying to install.Side slipping is NOT pro spin. It is actually ANTI spin.....

It is a real worry, Motz. The problem with forums is that anyone can write whatever they think might be the case and if they're reasonably literate can sound like an authority on the subject. And that then gets taken as gospel by others who still acknowledge they're in the learning phase.

 

I really think that if people are going to make statements about flying, or give advice, then they should qualify their comments with an indication of their actual experience. I don't think too many folks these days would be posting financial advice on a forum without due qualification and PI insurance.

 

The problem regarding this particular pro-spin/anti-spin thing seems to be that some folks mightn't know the difference between a slip and a skid.

 

 

[Ignition]

Maybe it's time for some 'Turn Smart'...

 

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

 

https://www.youtube.com/watch?v=xwrfEsCiltc

 

 

[M61A1]

A lot of posts which seem wrong can simply be the poster's inexperience at clear communication, or your misinterpretation of a word or phrase.

I think that this may be the case in regard to quite a lot of this thread.

 

 

[2tonne]

From a student's perspective, I find these discussions very interesting, but of course I have to be discerning in the information that I take on board.

 

Regardless, even if I pick up a different point of view from a thread compared with that of my instructor, I would NEVER attempt something new or different in the aircraft without discussing it with my instructor on the ground first. If I did try something new without discussing it first....well, I am not brave/stupid enough to do that...

 

 

[DrZoos]

Yes i used " pro spin controls" incorrectly and stand corrected. I meantsomething different but i wont go into that for obvious reasons .... i will leave it at that. But it is good that it got corrected. And thats the beauty of these forums there are enough people to usually pull up an error.