Attitude = speed control/power = pitch
I got taught slipping during my PPL and find it both great fun and useful. I can't imagine being able to do consistently good pfls without it and like Silvaire, I like being able to stay high until final approach.
That said, a few people have seemed surprised when I used the technique...
That said, a few people have seemed surprised when I used the technique...
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To me, the fact that a normal plane climbs, at a relatively constant speed, when power is increased, is simply the consequence of the pitch stability mechanism which every certified plane has.
The elevator has what is called decalage which AIUI means that the turning moment due to the change of elevator AoA about the pitch axis has to exceed the turning moment due to the change of wing AoA about the pitch axis. If you didn't have this pitch stability (which is in effect a negative feedback control system where airspeed is the setpoint) then the plane would be virtually uncontrollable manually.
I think that the cases where you are flying at say 65kt, trimmed, at low power, and increasing power causes the plane to nearly stall, are because one is flying on the back of the curve at 65kt (on that particular type). Otherwise, can a plane with such a large moment (due to power changes) about its pitch axis get certified?
The elevator has what is called decalage which AIUI means that the turning moment due to the change of elevator AoA about the pitch axis has to exceed the turning moment due to the change of wing AoA about the pitch axis. If you didn't have this pitch stability (which is in effect a negative feedback control system where airspeed is the setpoint) then the plane would be virtually uncontrollable manually.
I think that the cases where you are flying at say 65kt, trimmed, at low power, and increasing power causes the plane to nearly stall, are because one is flying on the back of the curve at 65kt (on that particular type). Otherwise, can a plane with such a large moment (due to power changes) about its pitch axis get certified?
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Peter
I think we get lost in the detail and the science rather than the basics,
We have two energy sources available to us potential energy we have created by dragging the airframe into the sky and the energy from our engine.
The glider having no power plant as such has to be towed ,carapolted or whatever into the sky to get the potential energy to be able to control airspeed by pitch on the way down.
Let me use the Citation as an example as using power for speed and pitch for speed and them both being right in a climb where we are not using the potential energy from the airframe.
Low level at Max N1 I may climb at 2500 fpm. I may elect to only want to climb at 1000 feet per min. Climbing at 1000 fpm I may decide that I don't want to go too fast so I reduce thrust and now am using power to control speed ,
High mid 30 FLs I am at max Ni coaxing a climb and only have pitch to control airspeed,
Eventually at max N1, climb rate is decreasing speed is decreasing AOA is increasing drag is increasing and I have nothing left to play with,
I have all the potential energy available but as I am still trying to coax a climb I am stuffed on going higher.
So as I say pitch for speed or power for speed are your tools which are for your use, both are important and both create the complete picture of controlling the aircraft
Coming Down from FL 350 I know have tons of potential energy available and tons of thrust available. I juggle the two energy sources maybe closing off engine power and just using the potential energy in the airframe to stop breaking VNE .Hence why Hence why saying I belong to the pitch for speed or power for speed brigade is such a nonsense ! Sorry for grammer written on I phone .
Pace
I think we get lost in the detail and the science rather than the basics,
We have two energy sources available to us potential energy we have created by dragging the airframe into the sky and the energy from our engine.
The glider having no power plant as such has to be towed ,carapolted or whatever into the sky to get the potential energy to be able to control airspeed by pitch on the way down.
Let me use the Citation as an example as using power for speed and pitch for speed and them both being right in a climb where we are not using the potential energy from the airframe.
Low level at Max N1 I may climb at 2500 fpm. I may elect to only want to climb at 1000 feet per min. Climbing at 1000 fpm I may decide that I don't want to go too fast so I reduce thrust and now am using power to control speed ,
High mid 30 FLs I am at max Ni coaxing a climb and only have pitch to control airspeed,
Eventually at max N1, climb rate is decreasing speed is decreasing AOA is increasing drag is increasing and I have nothing left to play with,
I have all the potential energy available but as I am still trying to coax a climb I am stuffed on going higher.
So as I say pitch for speed or power for speed are your tools which are for your use, both are important and both create the complete picture of controlling the aircraft
Coming Down from FL 350 I know have tons of potential energy available and tons of thrust available. I juggle the two energy sources maybe closing off engine power and just using the potential energy in the airframe to stop breaking VNE .Hence why Hence why saying I belong to the pitch for speed or power for speed brigade is such a nonsense ! Sorry for grammer written on I phone .
Pace
Last edited by Pace; 10th May 2012 at 07:40.
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Good points Pace and Peter, though perhaps on the edge of being relevent to the original post.
We have a very simple, basic question, posed by a new pilot of yet to be proven receptive attitude.... who has been absent from the discussion lately (since I posed a challenge to his (her?) self described knowledge......). EGKB?.....
We have a very simple, basic question, posed by a new pilot of yet to be proven receptive attitude.... who has been absent from the discussion lately (since I posed a challenge to his (her?) self described knowledge......). EGKB?.....
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Good discussion but miles away from the point. I see the speed with pitch in the PPL as an exersize which needs to be mastered early in the course and repeated in other exersizes until it is second nature. He may use the combined method eventually.
It's like the flight at minimum speed exersize. Flying around with a high power setting on the wrong side of the power curve. It is only a demonstration. Not an everyday technique.
D.O.
It's like the flight at minimum speed exersize. Flying around with a high power setting on the wrong side of the power curve. It is only a demonstration. Not an everyday technique.
D.O.
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Pilot DAR?
Absent from the discussion? You mean eating, sleeping for 8 hours, and working....
I can't sit at my comp 24/7.
And people STILL don't listen. I am using the technique the instructor mentioned. I think that's the 4th or 5th time I've mentioned that!
Absent from the discussion? You mean eating, sleeping for 8 hours, and working....
I can't sit at my comp 24/7.
And people STILL don't listen. I am using the technique the instructor mentioned. I think that's the 4th or 5th time I've mentioned that!
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Dont Overfill
I do take your point and have stated the same in all my posts.
The glider only has pitch for speed on still days.
Attach a tiny motor to said glider and you still have pitch for speed with some power for speed but the dominant principal has to be pitch for speed.
Our original poster who is BACK
needs to keep away from a high AOA and high drag situation thinking he can control his speed with power because he probably cannot.
He nevertheless has to be aware of both power sources and their relevance as he may at some time require not just pitch for speed but power too.
Pace
I do take your point and have stated the same in all my posts.
The glider only has pitch for speed on still days.
Attach a tiny motor to said glider and you still have pitch for speed with some power for speed but the dominant principal has to be pitch for speed.
Our original poster who is BACK
needs to keep away from a high AOA and high drag situation thinking he can control his speed with power because he probably cannot.He nevertheless has to be aware of both power sources and their relevance as he may at some time require not just pitch for speed but power too.
Pace
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Peter
To me that is a lesson in never trusting any Gizmo autopilot or otherwise or being lulled into a false sense of security as these things have a habit of going wrong when you least expect.
Hence why piloting skills are so important even in our day of technology
Flying older Citations I tend to get more system and autopilot failures than I want
all good for the soul
Pace
To me that is a lesson in never trusting any Gizmo autopilot or otherwise or being lulled into a false sense of security as these things have a habit of going wrong when you least expect.
Hence why piloting skills are so important even in our day of technology
Flying older Citations I tend to get more system and autopilot failures than I want
all good for the soul Pace
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I've had more autopilot failures than I can recall, but I still think that during the 99.9% of the time that the system works, you are a safer pilot using it and using the now copious spare brain power to monitor everything, than to hand fly and perhaps make a major cockup in another department.
I can hand fly in IMC fairly well, and have hand flown the TB20 most of the way down to Santorini (LGSR) and back, as well as parts of some N European airways flights, but I make simple mistakes during hand flown IR training (instructor or examiner in the RHS watching and issuing instructions) which I have never made when flying on my own, using automation at my discretion. In fact I have never made a major error or had any significant self inflicted "event" flying on my own, IFR, in CAS, and that's a good enough record for me...
The bit about letting the autopilot stall the aircraft when going down the ILS is just stupid. One can dress it up (the way that 1,000,000 posts elsewhere have tried to dress up the AF447 muppet-pilots) but the fact remains that if the pilot is not watching the speedo then all bets are off, and this is true on AP or off AP. Airspeed awareness is the absolutely #1 thing in flying. Well, alongside obstacle clearance I suppose.
I can hand fly in IMC fairly well, and have hand flown the TB20 most of the way down to Santorini (LGSR) and back, as well as parts of some N European airways flights, but I make simple mistakes during hand flown IR training (instructor or examiner in the RHS watching and issuing instructions) which I have never made when flying on my own, using automation at my discretion. In fact I have never made a major error or had any significant self inflicted "event" flying on my own, IFR, in CAS, and that's a good enough record for me...
The bit about letting the autopilot stall the aircraft when going down the ILS is just stupid. One can dress it up (the way that 1,000,000 posts elsewhere have tried to dress up the AF447 muppet-pilots) but the fact remains that if the pilot is not watching the speedo then all bets are off, and this is true on AP or off AP. Airspeed awareness is the absolutely #1 thing in flying. Well, alongside obstacle clearance
I suppose.
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Peter in that situation, the aircraft flirts with the stall but the stall in an L18C cub is barely a stall, it's more of a light buffet with a bit of nose down which unstalls the aircraft very quickly - it's not a CofA aircraft any more, but it was and there are ones just the same that are so I see your point. 60-65kts in the bottom of the curve as opposed to the speed unstable section but it is an extremely draggy machine.
Nonetheless a change in power doesn't automatically cause the aircraft to pitch for the speed that it has been trimmed to, equally if I'm flying a little faster and trimmed for say 75kts (top cruise speed being about 85) and pull the power completely it accelerates fairly quickly and I think it's not wise to assume that you will automatically pitch for an airspeed if you're in trim and change power but it is a technique that does work very nicely for a hell of a lot of aircraft and is unquestionably the basis for understanding the couple between, pitch, power, trim and airspeed.
Nonetheless a change in power doesn't automatically cause the aircraft to pitch for the speed that it has been trimmed to, equally if I'm flying a little faster and trimmed for say 75kts (top cruise speed being about 85) and pull the power completely it accelerates fairly quickly and I think it's not wise to assume that you will automatically pitch for an airspeed if you're in trim and change power but it is a technique that does work very nicely for a hell of a lot of aircraft and is unquestionably the basis for understanding the couple between, pitch, power, trim and airspeed.
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It might be an interesting Q whether trim=speed (regardless of power) only when on the right side of the curve?
I think that is self evidently true, because if you let the speed decay too far then you are looking at the scenario where a given power setting is capable of holding either of the two speeds and, if you were careless enough to let the speed decay to the lower one, that's where you will end up.
I think that is self evidently true, because if you let the speed decay too far then you are looking at the scenario where a given power setting is capable of holding either of the two speeds and, if you were careless enough to let the speed decay to the lower one, that's where you will end up.
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Peter
You don't have to justify yourself ! This is only a forum discussion and I know you are an excellent committed and very detailed pilot!
You also have a wealth of knowledge which exceeds my own so please don't take any of this discussion the wrong way.
Sometimes I will post to encourage discussion just my style so no offence
Pace
You don't have to justify yourself ! This is only a forum discussion and I know you are an excellent committed and very detailed pilot!
You also have a wealth of knowledge which exceeds my own so please don't take any of this discussion the wrong way.
Sometimes I will post to encourage discussion just my style so no offence
Pace
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Nope, does't work that way at a higher speed with cruise power set if closing the throttle the aircraft pitches down and accelerates beyond that speed.
I'll do a few tests at altitude next time I get the chance to see if it settles down slowly to the trimmed airspeed.
I'll do a few tests at altitude next time I get the chance to see if it settles down slowly to the trimmed airspeed.
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Our original poster who is BACK needs to keep away from a high AOA and high drag situation thinking he can control his speed with power because he probably cannot.
needs to keep away from a high AOA and high drag situation thinking he can control his speed with power because he probably cannot.
Moderator
Absent from the discussion? You mean eating, sleeping for 8 hours, and working....
I am using the technique the instructor mentioned.
Are you keeping your mind opened to the wisdom of others? I sense that some [very experienced] participants here think otherwise. It's up to you, they don't have to fly with you! Yours to win or loose - they don't really care that much!
And, what would you like to tell me about the surprize I had during an early STOL takeoff in the aircraft for which I offered the control force charts? If you were to fly that plane, what would you be expecting you'd experience? Might you run out of something?
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It definitely depends on the aircraft type. For example IME the Cherokee 140 will maintain a trim speed while using throttle to adjust descent rate much better than will a Warrior.
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Pilot DAR?
Family visit? Or you were flying across?
I still think you guys are a bit too "black and white" if you will. If don't use the technique you'll crash and die, and aaib will have reports on you and well laugh... lmao
Family visit? Or you were flying across?
I still think you guys are a bit too "black and white" if you will. If don't use the technique you'll crash and die, and aaib will have reports on you and well laugh... lmao