Pitch=Airspeed Power=Altitude ?

APACHEpilot

APACHEpilot

New Member
I got into a long discussion the other day with a Designated Examiner about how to teach pitch and power for landings. My whole idea about it and it was the way I was taught is, anytime power isn't a variable( takeoffs and landings if you set it and forget it ) pitch is airspeed and power is altitude. Now when power is variable ( cruise flight ) power then is airspeed and pitch is altitude. What do you all teach or what have you been taught ? The Examiner was saying that once you have configured for landing the pitch remains constant and if for any reason you have to add power during the approach it was because you've missed judged your base leg and going to come up short or be to high.I totally agree with that. He also said that if you have to add power for landing because you've missed judged the base leg you should do a go-around and to not let students continue with the approach and landing. :confused:
 
H
e also said that if you have to add power for landing because you've missed judged the base leg you should do a go-around and to not let students continue with the approach and landing. :confused:
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I disagree. For one it depends on the type of landing you are doing. If your doing a power off 180 sure then that would apply. But if your doing a short field landing the idea is to get set up than use power to control where you touch down. So having to add power would not constitute a go around in that situation. As far as power and pitch. If power is fixed than pitch controls airspeed. For example. During climb out after takeoff power will remain at climb power and you will pitch to maintain the desire climb airspeed. Any other time it is a combination that will get your desired result. Throughout most my training I always used pitch to control airspeed and throttle to control altitude. I understood that neither was independent of the other. If you change one you must change the other in most situations. But for me it was just easiest to remember that way.

As far as pitch being constant during approach to landing. That it a apporach used by people flying larger airplanes than dont have a flare to land. For example. My friend was a former air force transport pilot and he always described their landing approach as setting the desired pitch than using power to adjust the approach. He said they just maintained that desired pitch till touchdown. In small airplanes though that isnt practical nor neccessary. The pitch will change throught the approach to landing and will drastically change during the flareout.
 
Aim (pitch) for your landing point. If you need to adjust your glidepath/approach then use power for the adjustment. By setting your pitch for the landing zone you are making pitch a constant and now you only have one variable to adjust. This makes managing corrections much easier. When you have pitch and power both variables, it becomes confusing for a student to know which one to change and how one affects the other.

disclaimer: This is only a technique and if yours is different then great.
 
APACHEpilot said:
anytime power isn't a variable( takeoffs and landings if you set it and forget it ) pitch is airspeed and power is altitude. Now when power is variable ( cruise flight ) power then is airspeed and pitch is altitude.
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Wouldn't it be interesting if the laws of physics just reversed themselves when an engine turned on or off? But, as you might suspect, they don't.

First, you'll never make heads or tails out of this discussion by using the word "pitch". Get rid of it for the time being. Pitch is the angle that the longitudinal axis makes with the horizon and it is equal to the sum of the angle of attack (AoA) and climb angle. Pitch never controls anything; it's a result, not a cause. The real word(s) you should be using is "angle of attack". AoA controls airspeed in any steady flight. Other than brief fluctuations, to change your airspeed, you need to change your AoA. This is true regardless of whether you have power or not.

Where the confusion comes in is in level flight when you wish to make an airspeed change. For instance, to go faster, you normally add power and then increase the pressure on the yoke to maintain altitude. Since you make both control movements at the same time, the cause/effect connection is a little obscure. The actual speed increase comes from pushing forward on the yoke; if you didn't add power, you would find yourself in a descent. If you only added power, you'd find yourself in a climb at about the same airspeed, maybe slower.

Altitude control is determined by the quantity of excess power (or thrust). An aircraft without power will descend, because maintaining level flight requires power. If you have excess power beyond what is needed for level flight, the airplane will climb. If you have a power deficit, the aircraft will descend. You can change the quantity of excess power in two ways:

  1. Change the throttle setting, or
  2. Change the drag on the airplane by changing your airspeed.
For instance, if you're in cruise, if you pull back on the yoke, you will slow the airplane, which reduces the drag on the airplane which will cause the airplane to climb. Unless, of course, you get behind the power/drag curve and then pulling back on the yoke will cause the airplane to descend.

This is the way the physics works, so you don't need to come up with different sets of rules of for power/no power, or front-side/backside of the power curves.
 
Jbroz04 said:
H
I disagree. For one it depends on the type of landing you are doing. If your doing a power off 180 sure then that would apply. But if your doing a short field landing the idea is to get set up than use power to control where you touch down. So having to add power would not constitute a go around in that situation. As far as power and pitch. If power is fixed than pitch controls airspeed. For example. During climb out after takeoff power will remain at climb power and you will pitch to maintain the desire climb airspeed. Any other time it is a combination that will get your desired result. Throughout most my training I always used pitch to control airspeed and throttle to control altitude. I understood that neither was independent of the other. If you change one you must change the other in most situations. But for me it was just easiest to remember that way.

As far as pitch being constant during approach to landing. That it a approach used by people flying larger airplanes than don't have a flare to land. For example. My friend was a former air force transport pilot and he always described their landing approach as setting the desired pitch than using power to adjust the approach. He said they just maintained that desired pitch till touchdown. In small airplanes though that isn't practical nor neccessary. The pitch will change throught the approach to landing and will drastically change during the flareout.
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That's exactly what I thought. I think he was telling me something that relates more to heavy's and not to smaller training aircraft.
 
The "what controls airspeed and what controls altitude" subject has been beaten to death, and as with so many subjects that are beaten to death, no agreement exists. What I am going to write is what "I" teach, although I've been through aeronautical engineering classes and lengthy discussions that would say this is not so.

I am concerned with what is more effective. On the front side of the curve (where we normally fly), airspeed is more responsive to power and altitude is more responsive to pitch. On the back side of the curve (as during slow flight), altitude is more responsive to power and altitude is more responsive to power.

When you encounter someone making the argument that power controls altitude, nod your head. Then ask them if they were doing crop dusting inches above the crop and they realized the wheels were starting to tick the tops of the crop, would they pull back on the stick or would they add power.

As to the DPE's opinion on having students do go arounds if they have to add power, I don't see any value in doing so compared to the serious waste of training time. If an approach is low, the better answer is to fly back to the proper position and then continue a stabilized approach.
 
BTW, congrats to the OP for making the first 10 page thread of the new year.

"But Subpilot, this is only post #7, how can you say that?"

Just wait and see. These kind of post are like California wildfires.
 
Pitch is very relative for pilots. Maybe in aeronautical engineering class it is a non-useful term but the last time I flew My attitude indicator told me my pitch attitude and my Mk1 eyeballs could see pitch attitude through the windscreen. I know that AOA indicators exist but not on the planes I fly. I can set pitch and power to a known value and achieve known performance.
 
Most of the time I talk about pitch rather than AOA because it seems to confuse the beginning student. Even though your actually changing the AOA, pitch just seems to work better. In most cases.
 
APACHEpilot said:
Most of the time I talk about pitch rather than AOA because it seems to confuse the beginning student.
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It's your job to unconfuse the student. ;) Teaching something that's incorrect because it's easier to understand is a little bit like the drunk who looks for his car keys under the street lamp because the light is better there, rather than looking where he actually lost the keys.

If you understand the difference between AoA and pitch, then I think you can eventually get it across to the student. It won't happen in a day, or a week, but if you continually hammer it throughout training, it will eventually sink in.

In my view, communicating an understanding of AoA is about the single most important concept that you can convey to a student and you shouldn't trample this issue in the hurry to reach some other goal.
 
Tgray: I agree with everything you said. However, for a private pilot I would have left this, "Change the drag on the airplane by changing your airspeed." out. It makes perfect sense to me, but I suspect it would glaze over a great deal of students. I also don't find it relatively useful either. Maybe it was just how you explained it, there could be a simpler way.


The rest here, I have some nit picks but instead of saying my beliefs I just want to ask some questions.

jbroz said:
If power is fixed than pitch controls airspeed.
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So if power is being changed pitch no longer controls airspeed?


jbroz said:
"That it a apporach used by people flying larger airplanes than dont have a flare to land.
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**Apache** Would you mind answering this set as well?

Read these with the assumption that a constant pitch is used until round out and flare (about 50' AGL):

Why can't it be used for smaller aircraft?
Wouldn't constant pitch help judge trends of sinking below or rising above the glide slope?
Can you really see those trends if you are constantly changing your visual picture with pitch?
Do you think teaching constant pitch would lessen, increase, or have no effect on a persons likelihood of stalling at lower altitudes? Why?



subpilot said:
Aim (pitch) for your landing point.
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How does one keep a constant pitch when they are told to reference the landing point?

subpilot said:
Pitch is very relative for pilots.
Click to expand...

You say pitch controls airspeed. How? (Please answer this without using the term AOA.)
 
shdw said:
I would have left this, "Change the drag on the airplane by changing your airspeed."
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You can't leave it out. You can change altitude by using the yoke and so you have to explain it, rather than pretending it doesn't happen.
 
Can't we just merge this thread with the last 10-page argument we had on this subject here?
 
shdw said:
**Apache** Would you mind answering this set as well?

Read these with the assumption that a constant pitch is used until round out and flare (about 50' AGL):

Why can't it be used for smaller aircraft?
Wouldn't constant pitch help judge trends of sinking below or rising above the glide slope?
Can you really see those trends if you are constantly changing your visual picture with pitch?
Do you think teaching constant pitch would lessen, increase, or have no effect on a persons likelihood of stalling at lower altitudes? Why?





You say pitch controls airspeed. How? (Please answer this without using the term AOA.)
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1. Yes it can be used for smaller aircraft when done correctly. Power, Pitch, and Configuration gives you airspeed. Agree or Disagree ? (AOA) for pitch if you so desire.
2.Absolutely.
3.No you wouldn't be able to see the change to your visual picture or your desired glide slope if your constantly changing pitch.But if your constantly changing pitch it's because you've did poor planning on you base leg ? Agree or Disagree ?
4.It would lessen the the chances of stalling at lower altitudes but also if your pitch, power and configuration stay the same won't airspeed stay the same.What about night landings over farm fields with no visual reference outside.What would you do then?

Didn't mean to open up a huge can of worms here. Just wanted to hear everyone's opinion.:beer:
 
APACHEpilot said:
1. Yes it can be used for smaller aircraft when done correctly. Power, Pitch, and Configuration gives you airspeed. Agree or Disagree ? (AOA) for pitch if you so desire.
2.Absolutely.
3.No you wouldn't be able to see the change to your visual picture or your desired glide slope if your constantly changing pitch.But if your constantly changing pitch it's because you've did poor planning on you base leg ? Agree or Disagree ?
4.It would lessen the the chances of stalling at lower altitudes but also if your pitch, power and configuration stay the same won't airspeed stay the same.What about night landings over farm fields with no visual reference outside.What would you do then?

Didn't mean to open up a huge can of worms here. Just wanted to hear everyone's opinion.:beer:
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Power + Pitch = Airspeed + Altitude

You have to have both. You can use Power or Pitch to change airspeed, and you can use power or pitch to change altitude. The effectiveness of this, however, is predicated entirely on which side of the power curve you're on.
 
APACHEpilot said:
1. Yes it can be used for smaller aircraft when done correctly. Power, Pitch, and Configuration gives you airspeed. Agree or Disagree ? (AOA) for pitch if you so desire.
2.Absolutely.
3.No you wouldn't be able to see the change to your visual picture or your desired glide slope if your constantly changing pitch.But if your constantly changing pitch it's because you've did poor planning on you base leg ? Agree or Disagree ?
4.It would lessen the the chances of stalling at lower altitudes but also if your pitch, power and configuration stay the same won't airspeed stay the same.What about night landings over farm fields with no visual reference outside.What would you do then?

Didn't mean to open up a huge can of worms here. Just wanted to hear everyone's opinion.:beer:
Click to expand...

Disagree. A lot of times I'm bleeding off speed and working out the power on final approach so my pitch is constantly changing as required. My glideslope is staying roughly constant, but my pitch is not.
 
shdw said:
How does one keep a constant pitch when they are told to reference the landing point?



You say pitch controls airspeed. How? (Please answer this without using the term AOA.)
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1. You keep the aimpoint locked frozen on the windscreen and this then stabilizes your pitch. Think of it this way, if I point the airplane toward something then that is where it is going to go.

2. I never said that. I associate power as the primary control for airspeed.

The reason these threads always go so long is because there is no one right or wrong way to fly an airplane. If your technique works for you that does not mean that a different technique that works for someone else is wrong. I also don't think the average pilot needs to learn a doctorite's level of theory on aerodynamics to fly an airplane. They need real world cause and effect knowledge. But that is just me. If other's feel a pilot who doesn't have the lift formula commited to memory (<-- example) has been wronged by there instructor and is unsafe then that is there opinion.

Happy New Year BTW. This discussion has already been beaten up to death and the OP searches for "Pitch Power Airspeed," he will come up with days of reading on this stuff.
 
I teach:

Use Power for airspeed and Pitch to hold altitude, in level flight, AND on the front-side of the power curve.

All other times, use the converse - Power for altitude, Pitch for airspeed(i.e. ascending, descending, or remaining level on back-side of power curve e.g. during slow flight)
 
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