Attitude = speed control/power = pitch
 

WHAT?!

So backwards, I landed fine last time doing it my own way. And now today he introduced this pitch controls speed and power controls attitude. Is it MANDATORY? Or is it a widely used technique?

It's not carved in stone; it's more complex than that. But setting pitch for speed, power for rate of ascent / descent is a good way to learn.

Once you are qualified and start to gain experience you'll find a lot of what you were taught in the PPL process is just the beginning. You have to start somewhere, and doing it by processes and numbers works well until you have the experience to do it from first principles.

It's just a method to break it down into easy chunks when you are learning how to establish a constant steady approach.

A lot of civvy schools teach this method, if high or low adjust power to fix it, if fast or slow adjust pitch attitude. This is really just a way of thinking which to adjust first. If you are high you would reduce the power, but you would soon need to lower the nose or the speed will bleed off. One way of imagining this pairing of attitude and power is that your arms are linked by a piece of string, like you were wearing mittens as a kid. If you adjust one thing, e.g. reducing power, you do the opposite with the other hand, in e.g. pitching forwards.

The military tend to teach the opposite, power for speed and pitch for rate of descent, as this method works a lot better when you come to fly an instrument approach or fast jet. Either way it amounts to the same thing and is just a way of breaking it down in your mind into something more manageable.

Thank you very much. It made it more complicated for me, definitely won't be using that technique ever again, it was like adding unnecessary steps.

EGKB,

Pitch does control speed.

Power does control rate of climb or descent.


Some instructors will elect to teach it the other way around, and this does seem to work as well for instrument approaches in particular.

The reality is that they are inexplicably tied to each other because power also has a pitch effect, and pitching also creates a rate of climb or descent. In the vast majority of aeroplanes increased power causes a pitch-up and a reduction in trim speed, whilst a reduction in power causes a pitch-down and a consequent increase in trim speed.

So:

Correct approach angle / too slow = pitch down + more power
Correct approach angle / too fast = pitch up + less power
Correct speed / too high = reduce power + pitch down
Correct speed / too low = increase power + pitch up.

(And at the current stage in your training = if both are wrong, probably go around and try again next time; if feeling braver AND there's plenty of height to play with, sort out airspeed first, then flightpath).

G

That all means nothing to me, I'm a practical guy, everything sort of is simultaneous for me, doing several things at once...

I wonder how my other instructor teaches as I have't done any landings with him yet!

Once you start IFR flying you'll find that on the ILS, your position on the glideslope (pitch) is controlled by elevators and your speed (to keep the CAT behind from going up your chuff) is controlled by throttle (Power).

Confusing innit?

Cusco

Are you saying different instructors at the same school are teaching different techniques at this early stage in your training?
If so I suggest you seek clarification from the head of training.

It will help a lot to separate the effects out in your mind.

It is a foolish arrogance to think that you don't need these simplifications. I have a PhD in flight mechanics, and still find it vital to keep coming back to these simplified models in my flying.

Personally I think that switching instructors is a bad habit and you are better sticking with one so that you are learning consistent method. However, if they teach in the same school then they should be standardised on the same technique.

The pitch for speed approach I described is pretty much standard across VFR flight training worldwide. It works.

G

It's not arrogance at all, it's completely subjective, some methods work for some, some for others.

I'm not saying pitch doesn't control speed, it does. But to me everything is backwards, there's a reason why there's an elevator on the plane to control pitch, it worked for me perfectly on all approaches/landings so far except for today when I tried the opposite technique....

I'm not sure if they teach the same technique, I haven't landed with the other instructor, he was on my first lesson and I wasn't taking much no on the landing as to what he was doing.

You appear to have stumbled upon what's referred to as the "point and power" technique - much loved by instrument instructors and very relevant to a big jet like a 737.

But in VFR in a single engined light aeroplane, really I'd stick with the classic pitch for speed and power for rate of descent. If this takes a little getting used to after developing an initial bad habit - live with it!

And as I said, I would stick with one instructor and their way of doing things as far as you can. Neither will be wrong, but you don't need the chopping and changing.

G

I've heard this one before, not saying it's wrong but on an ILS approach I always use the throttle to control glideslope.

I disagree with everyone :E and I will explain why!!!

Think of two power levers the throttle and the elevator.
The throttle will tap into engine power.
The elevator will tap into potential energy inherent in the airframe.

Take the simplest form! remove the engine from the equation ie a glider on a still day and there is only one form of potential energy to tap into to maintain speed and that is the potential energy in the airframe.
In that situation you have one power lever and that is the elevator.
Add an engine and you have two power sources available the airframe and the engine.

So really neither is correct as it is using both sources which is accurate.
Take a light draggy trainer with a low powered engine and pitching for speed becomes more important.

Take a high powered slippery aircraft and pitching for speed becomes less important while power for speed more important.

Really its a play between using two power sources both equally important! Ignore one or follow one rule at your peril!

Take an inexperienced student in a low powered draggy single and the priority has to go to pitch for speed as that will keep the pilot away from a stall situation.

but I repeat you have two throttles to tap into energy why use one????
Ignoring one has the potential for real danger.
Both principals are flawed!

Pace

Can't really argue with that other that in a light draggy trainer on an instrument approach using throttle for glideslope control maintains the airspeed, needs no movement on the yoke (always handy when on instruments) and requires no trim change. It works for me anyway, use whatever works for you.

Surely, for a given configuration, your airspeed is set by the trim wheel :)

All the engine does is control the rate of descent. This means that if you are happy just to go down, you don't need an engine.

This is an interesting debate... partly due to the number of different views/experiences....

If you are learning to fly and land a light aircraft, VFR and are still doing your PPL then you need to set aside all talk of ILS - it's too early for that.. you need to learn to fly the aeroplane first.

The principle that works for me...

Base leg and long final... get the aircraft properly set up, power/attitude/trim - you need to establish a stable approach at the right speed.

All the way down the approach, one hand on the throttle and scanning between the runway and the ASI you are trying to keep this initially stable approach going

As you descend, the runway perspective may start to flatten out... you are sinking! The aircraft needs more energy so apply a little more power and adjust attitude to maintain airspeed.... (as stated the two go together).

If the runway perspective starts to lengthen you are getting too high... the aircraft needs less energy.. reduce the power and adjust the attitude.

This needs to be practised until it is instinctive... the day will come when, at 300' on a gusty day, you might suddenly start to sink rapidly... at this point you need power!! So once you have this habit you are going to avoid hitting the caravans at Caernarfon or the factories/hedge at Hucknall etc etc...

As stated - if your career goes on to bigger beasts, jets and/or Instrument approaches there are new things to bring in but all of these will be better if you learn the basics now.

Agree with Geng about one instructor... I was the "son of many instructors" and it confused the life out of me (I guess putting a question on here could do the same - but I learned without t'interweb).... as you get experience the differing views/techniques are easier to cope with but at first... one set of techniques will do...

Good luck... happy flying... Mike

Peter

What if you don't have one ?:{

Pace

I think this is one of the more fascinating pprune discussions.

I'm in the Genghis/Pace camp in that the two controls are linked. In the early days you have to give a student something to hang his hat on and we break down the mechanism used into easy chunks. The reality is that you will have to use both controls when adjusting speed or rate of descent on approach.

But surely your speed is already stable by the time you intercept the glideslope? It's all hanging in there at 105 kts or whatever and just knocking 2-300 rpm off the donk will have you sitting on the glideslope at 105 kts as well, no elevator or trim input needed. Or maybe I have a unique body mass/fuel mass and it's just luck that it works for me? Genuine question.

Thing

That will be because you are now tapping into both energy sources!
You have a set power to give you a set airspeed.
You then reduce that power.
If you attempted to hold altitude on the reduced power the airspeed would reduce but you let the aircraft descend hence making up for that lost power by tapping into the inherent energy in the airframe.
That is a simplified view as we all know that AOA and drag come into it but the principal is that you have two energy sources available one from the powerplant the other from the airframe.
Take your scenario you have reduced power and allowed the aircraft to descend which maintains that airspeed.
All going well till you hit a rising or sinking pocket of air what happens then?

Pace

Firstly, we're not talking about a glideslope, we're talking about a student pilot on a visual approach.

Secondly, I think it's you thing. I reckon you are pushing or re-trimming to maintain speed in most light aeroplanes with a 300 rpm reduction.

G

Thing, there are some aircraft that will react as you describe, under certain circumstances. However, the overriding point is that if you change one of the controls, it is highly likely (nay, almost definite) that you must do something with another.

Looking at this another way, if you choose to fly 'point and power' and discover you are too slow, you will add power. In order to counter the subsequent change in attitude (dare I say AoA) you will need to change the pitch. In reality, you are actually reducing AoA to counter the increased speed you have given yourself. You could get exactly the same effect by firstly changing pitch (thus increasing airspeed) and then increasing power in order to retain/attain a particular rate of descent.

One final point. After a few hours you tend not to think about this and you just fly the aircraft as you would drive a car. You don't 'think' about gear changes, do you?

Thing

I go with Genghis on that. I am sure you have tried an exercise at altitude of flying an airspeed in the descent?
You cruise at 100 kts and push the nose over! To maintain that 100 kts you have to bring back power. Note descent rate.
Now push the nose over even further! again to maintain your 100 kts you will have to bring back power even further. Note descent rate now!!
Push the nose even further and you maybe back on the stops with power you can no longer maintain 100 kts clean without chucking out some drag as now the energy you are getting from the airframe exceeds the amount required to maintain the 100 kts.
You can no longer play the two energy sources as your powerplant is at idle and you cannot reduce that further.
To maintain the 100 kts all you can do is to reduce the power from the second energy source by reducing the descent.
Of course you could hang out drag but thats another subject.

Pace

EGKB What are you going to do then when you are short final and a little high and fast, pitch the nose down at the ground and pull the throttle to idle? In a Piper or Cessna you can be pretty sure that isn't going to get you down any time fast.

Conversly pitching up away from the runway ( yep its counter intuitive ) to get your speed under control, and reducing the throttle to idle to increase your rate of decent and you will start coming down pretty sharpish.
..Remember also that pitching up is also going to increase your AoA which is going to also create more drag and help slow you down. Pitching down is going to decrease your AoA.

My advise, don't presume that you know better than your instructor, and don't give up on this technique just because its counter intuitive...are you going to do this with all other elements in the syllabus as well? Pitching for speed will give you a much greater control of your approach speed and save you endless balloons / floats down the runway.



Your elevator is your AOA control not your pitch control.

EGKB, please don't take this the wrong way, this is friendly advice.

Questioning your instructor on Pprune at an early stage of your training and then declaring after 2 responses to the thread that you are never going to use the landing method taught does not in my view show an appropriate willingness to learn.

You cannot pass a PPL solely from advice on here. You need to develop trust in your instructor. Why not ask him/her to explain on the ground and then demonstrate in the air the reasons for the methods taught?

Well Mariner9 got there before me. Two bits of advice (both already mentioned) from me:
1. Ask your instructor to explain and demonstrate (he or she will respond well to such a request). Then do what you are told.
2. Get a copy of "Stick and Rudder" by Langeweische and read it several times.

Oh alright three bits of advice:
3. Don't confuse yourself by asking folk on the Internet to give you advice unless you know their credentials

Have fun

H

Yes

No, for a student pilot at this stage in EGBK's training, use a current training book such as that by Jeremy Pratt. Stick and Rudder, which is old, and does not reflect latest thinking is well worth reading - for an experienced pilot who has a frame of reference to hang it on. It's the wrong thing for a student PPL.

I'm very happy to state mine (indeed I do in my profile, but can add 64 types as PiC and 4-figure hours if that helps), but I'd also comment that nobody's paying for my advice here, and therefore it's worth approximately what you paid for it.

The bit about having fun on the other hand I agree with utterly.

G

Mariner Heston

Please feel free to point out any incorrect information from whoever in the thread as in any forum discussion that is how we get to the truth.
I for one am happy to stand corrected?

Pace

GtE - yes of course you are right about reading current PPL training books as the main source of reference (I made the assumption that a PPL student would already be reading them, but on reflection I see that that may not be so). But I can't agree with steering clear of Langeweische because its the only book I know of that actually explains in sufficient detail most of the answers to questions that learning pilots ask that are phrased something like "Yes, but WHY does it do... ?" As L says somewhere in the the intro, its written for pilots to understand, with only enough aeronautical theory and no more.

Pace - its not about incorrect information: its perfectly possible to be confused by multiple explanations all of which are correct in their own way.

H

So gliders cant fly?

So when you flare with the throttle closed you cannot control ROD by pitch?

So in a low level go around just above the runway after a large bounce you will pitch down to increase the speed?

So if the engine stops you cannot control ROD at all?

Thats the problem with making unqualified statements!

You need to understand what the PRIMARY method of controlling ROD/height and airspeed on finals is but also understand that a combination may need to be used, such as in the Go Around. You also need to understand that both can be used the other way round as a secondary method of controlling height and speed!
.

I was not questioniong your (or indeed anyone's) responses Pace, I was questioning the OP's stated intention to use a Pprune thread to disregard his instructor.

Do this, and that happens....
 

At early stages of learning to operate any machine, you use your very modest judgement to figure out what you need it to do, then you use your even more modest skill to control the machine to do it. So you're figuring out what to make your hands and feet do to make the machine move. Two stages. This demands a simple understanding of "do this to make that happen". This is particularly true of aircraft, which are subject to more forces and variables than most machines. That's what instructors are taught to teach you, and you're paying for it, so you may as well listen.

When you reach the stage of hundreds of hours of flying skill, you'll find that you can control the plane with your mind directly, and thinking about what your hands and feet are doing is not necessary. These understanding aids will not be needed anymore, but you're not there yet.

When your instructor demonstrates slow flight, pay particular attention to these characteristics. (Really, landing is slow flight anyway, at its later stages). With the aircraft flying level with full flaps, lots of power, and very little of Pace's very important potential energy, the elevator control will control pitch attitude very nicely, because there'll be no energy to turn into a climb. Power changes will cause the aircraft to climb or descend with surprisingly little pitch attitude change. If you're really neat about doing this, the effects of P factor can be observed too.

When you're flying faster, the effects are more subtle, and likely to be seen to overlap each other. Follow your training......

Heston

But that is the whole point re these discussions is that we do dissect subjects ! Some information is wrong and is usually corrected at some point.
That is why it is important to look at the whole thread and postings and never take one opinion as Gospel. In the end there is usually a concensus
As for students of course their main contact is their instructor and they cannot fight the instructor by going off on their own tangent! That does not mean the student should not question or ask for more detailed explanation as to why??
I totally agree that with an inexperienced pilot in a low powered draggy aircraft pitch for speed has to be the safe way as that is the most secure way of keeping away from a high AOA high drag situation.
My only point is that the true picture is energy management and pitching for speed is not the full picture and neither is power for speed.

Pace

A bit of a design characteristic of the OP I think. He has previously expressed strongly some rather incorrect views concerning, for example, how many landings are likely to be needed before solo. Not atypical behaviour of male homo-sapiens in the 16-25 bracket.

G

Negative Genesis,

I was simply shocked at how many T&G's one pilot needed, 118 I think it was. And I simply questioned why it was so high, and some people agreed that it's quite high...

Mariner9,

Thanks for the post, I disagree. I have a great willingness to learn. And I did speak to my instructor about the technique, he said it's the way he teaches it. And as others have said it's not a law, you don't HAVE to use that technique, each to their own, that makes things harder for me. For some it might make it easier, but it's not mandatory is it?

"You need to understand what the PRIMARY method of controlling ROD/height and airspeed on finals is but also understand that a combination may need to be used" - This is what I agree with, I know you guys are more experienced than me, and I guess I might sound a little arrogant, but I'm simply investigating a technique and stating my opinion on it.

I pulled the yoke back to go higher and forward to go lower, increased power to increase speed and visa versa. That has worked for me, instructor said my app was perfect, then I tried the opposite and everything was fine except my mind got clogged up thinking about opposites/doing things in the reverse order.

Again I echo what I said before and when you find yourself high and fast on short final, the above technique is only going to cause you more problems!

I'm not an instructor but I've been trained various ways and fly jet transport aircraft now.

Like the original poster, I found that concept utterly confusing in the early days, to the point that I would sit and think about what needed to be done given what I was seeing out the window and confirmed with the ASI. It left me massively behind the aircraft and as such, I haven't entertained the concept since.

The easiest way I found to fly an approach that works in your C150 to your heavy jets is use pitch and power in unison. Imagine a piece of string connects your hand on the throttle to the hand on the yoke. If you move one, you move the other in the opposite direction. A bit like when you swing your arms when you run; when one arm goes forward, the other goes back. Of course, in this case, those movements can be as minimal as a squeeze of pressure or a 2mm move in throttle.

If you're high, you lower the nose slightly and simultaneously reduce the power slightly. Once you're on the correct path, you'll raise the nose slightly, not forgetting that you'll need an increase in power to maintain the speed. The same goes for being too fast or too slow. If you alter one, alter the other.

Two caveats to that. One is that you'll find, as you get more experienced, that you can work combinations of that technique to be more efficient and effective but it's a good process to hang your hat on to start with. Particularly, you'll find that a small change in power on an approach that is spot on in pitch requires, in some cases, no change in pitch if you were looking to alter your approach speed by a few knots.

The second is that you should be wary of bringing your own techniques, and those of people on an anonymous forum, to your training regime. It can in some circumstances do more harm than good, especially if you haven't consulted your instructor or the school. That said, it's a recognised technique that works for most but can be fairly dependent on experience.

Good luck!

When you've got a few hundred hours is the time to start deciding what technique suits you best. When you have a few tens and haven't soloed yet, the person best equipped to make that decision is the instructor.

G