Best Rate Of Climb Question

[Pearo]

So there is a stalling speed, which has a corresponding stalling angle for any given aircraft at a given wait. It is to fly at this speed, at x weight, the aircraft must have an angle of attack of whatever it is. Correct?So which is the fixed variable? By the sounds of it its the stalling angle and the stalling speed is dependent on the weight of the aircraft. And by increasing the weight of the aircraft, for a given stalling angle (commonly 16 degrees) the stalling speed will INCREASE.

Is this all correct? Anyone confirm?

Not correct as I read it. The stall angle or critical AoA is fixed. The wing will always stall at that angle. Its the speed that wing stalls at that changes. The best way to understand this is to draw vector diagrams.

 

 

[NljbA380]

So by saying if i do them at the same speed, im ignoring the term BEST. My bad. The best climb performance is given by a given speed depending upon whether it is best rate or best angle. I think i finally get it all. Sorry for being a pain in the butt.

 

Why is the vertical speed of a best rate always slightly greater then a best angle? I know its due to the slightly extra height gained, but why is this extra height gained say over a time interval of one minute? Is it just the nature of comparing the two climbs?

 

Can anyone answer this question?

 

Just out of curiosity. I know that when your flying in a nose up attitude, the angle of attack is the angle between the air flow and the chord of the cross sectional of the wind. How is said angle of attack influenced/calculated in bank and even in a ascending bank? How is it different from each side of the wing?

 

Can someone confirm this. I just read. "The only two terms in the lift equation that can be different between the two wings are lift coefficient (ie AOA) and speed. We have agreed the speed of the outer one is up so it must have less AOA."

 

Say were in a bank to the left. Obvisouly the right hand side of the wing is travelling at a quicker speed. When they say the only thing that can be different between the two wings are lift coefficient and speed. How is this true, because if your in a bank, then one wing is going to have to produce a greater amount of lift. And in which case, if we are banking to the left, the right hand wing is going to have both a greater speed and as a result angle of attack isnt it? And that explains why because of the greater angle of attack, it will stall first at a higher speed. And thus why we flip to the right when we stall. is this the correct thinking?

 

 

[planesmaker]

No. In a rate 1 turn the difference in speed of both wings is less than a fraction of a kph, so small as to be insignificant.

 

In a steep turn eg 100m diameter turn performed at 60 kph(sorry it's easier to keep it metric) take less than 20 sec the speed difference from wing to wing is only 3kph. At 100kph (53kts)the difference is only 5.4 kph(less than 3 kts)

 

 

[planesmaker]

In a balanced turn (I emphasise balanced) the outer wing may stall 1st because of aileron used to bank the aircraft has increased the AofA of that wing. This is why in a stall you do not try to pick up any wing drop with aileron because use of aileron will further increase AofA further deepening the stall of that wing. Hope this simplifies and answers your question.

 

 

[facthunter]

You had better revisit your climbing and descending turns theory. Most aileron is applied entering and exiting a turn Ie when you roll the plane to the desired bank angle .

 

Consider the helical paths described by both wingtips in both the climbing and descending situation. It is different. You will have to hold aileron into the turn in a descent as the inner wing has the higher angle of attack and the reverse applies in a climbing turn where the outer wing has the higher angle of attack.. The speed difference is not of much consequence as the extra distance in a full 360 degree turn is 3 X wingspan approx. Nev

 

 

[Aldo]

Can somebody explain

NljbA380

 

Vx vs Vy have a look athe pictorial attached it is that simple

 

 

To help remember which is which, I imagine a chart where the x-axis is distance, and the y-axis is altitude. If distance (x) is a concern, then use Vx to minimize the x value for a given y. If reaching a given altitude (y) quickly is your primary concern, then use Vy.

 

If you are concerned about looking after your engine (and you should be) climb at the fastest speed which gives you a reasonable rate of climb.

 

Also, can someone please explain the stalling angle of attack/speed

"The angle of attack is the angle at which the wing meets the air."

 

An aerodynamic stall (wing) is only dependent on the angle of the relative airflow to the leading edge (keeping it simple) it is not dependent on speed an aerodynamic stall can happen at any speed and any nose position (aircraft attitude) e.g. you can stall pulling out of a high speed, low nose attitude, low power dive or in a slow speed, high power high nose attitude climb.

 

Aldo

 

 

[motzartmerv]

G'day Nijba.

 

Forums are a fantastic place to share ideas, gain some insight and swap stories. Unfortunately, they can also be a source of great confusion and can erode some of the foundations your instructor will (should be) be laying and building on during your training.

 

Your questions are excellent and show you have a reasonable grasp of some of the basic concepts, however, your Instructor is the dude i would be discussing the more complex things with. He/she is trained to impart the correct information, at the right time and lots of pilots like to have a crack at explaining things as they understand them, which is where much of the confusion comes from.

 

There are a few subjects that you simply MUST understand properly to be safe, and some of those you have touched on in this thread.

 

Enjoy the conversations here, but grab a coffee, sit down with your Instructor and 'learn".

 

 

[Pearo]

G'day Nijba.Forums are a fantastic place to share ideas, gain some insight and swap stories. Unfortunately, they can also be a source of great confusion and can erode some of the foundations your instructor will (should be) be laying and building on during your training.

Your questions are excellent and show you have a reasonable grasp of some of the basic concepts, however, your Instructor is the dude i would be discussing the more complex things with. He/she is trained to impart the correct information, at the right time and lots of pilots like to have a crack at explaining things as they understand them, which is where much of the confusion comes from.

 

There are a few subjects that you simply MUST understand properly to be safe, and some of those you have touched on in this thread.

 

Enjoy the conversations here, but grab a coffee, sit down with your Instructor and 'learn".

You have to take what is taught by instructors with a grain of salt also. The simple fact is, your instructors is a pilot who has been spoon fed the same bullshite as he is onfeeding to the student. I am a late learner to flying, but I have the advantage of an engineering backround, and I can assure you that a lot of stuff taught to student pilots is absolute rubbish. Its a hard line to walk, because a pilot is not an engineer, but you need to come up with a model that a non-engineering type can understand. The model only often tells part of the picture.

 

When I was doing the theory part of the PPL, this bothered me a lot more than it should. A pilot needs to understand some basic fluid mechanics so they can understand why a wing stalls for example, but how do you go on to teach that in simple method that does not require a 4 year engineering degree plus 10 years of practical experience. In my opinion, I think they need to do away with a lot of stuff, like the coanda effect, bernoullie, newton etc and go back to practical modelling. What they teach now is not what happens in reality, its much, MUCH, more complicated and in fact, a lot of theory that is taught is factually incorrect, confusing and very misleading.

 

If I can say one thing (which I dont think will pass a practical exam), is go read the book 'stick and rudder'. I forget the name of the author, but its sufficiently dumbs down the physics in a way that a non engineering type can understand. Its not perfect, but its a lot better than a lot of the modern texts that you read.

 

Disclaimer: I am not saying an instructor is wrong. The great thing about teaching is it helps you better understand the subject, so often an instructor is a good person to bounce questions off. Just make sure you can distinguish between the practical and engineering side of aviation, as they are very different.

 

 

[NljbA380]

G'day Nijba.Forums are a fantastic place to share ideas, gain some insight and swap stories. Unfortunately, they can also be a source of great confusion and can erode some of the foundations your instructor will (should be) be laying and building on during your training.

Your questions are excellent and show you have a reasonable grasp of some of the basic concepts, however, your Instructor is the dude i would be discussing the more complex things with. He/she is trained to impart the correct information, at the right time and lots of pilots like to have a crack at explaining things as they understand them, which is where much of the confusion comes from.

 

There are a few subjects that you simply MUST understand properly to be safe, and some of those you have touched on in this thread.

 

Enjoy the conversations here, but grab a coffee, sit down with your Instructor and 'learn".

I feel that because of the vast majority of the responses here, while it is good, confused me even more in a sense. Im still getting used to the whole process of learning to fly. And am defiantly taking your advice on board with regards sitting down with the instructor. As a younger guy I must admit, i feel a tad awkward wanting to do so. But its ultimately for the better of my understanding/knowledge and safety that I should. Maybe as im working through the textbook i should compile a range of questions I should ask next time I go flying.

 

 

[SDQDI]

Nljb I have to agree with Mozart on this one. Yes there is a lot of good info on this forum BUT when learning to fly too much info at some stages can be detrimental and even disheartening trying to get your head around it. Whereas your instructor can fill you in as you go and it will all fit together a lot better for you.

 

By all means read advice on forums such as this but take any serious questions back to your instructor and double check them just to ensure you aren't either getting a bum steer (dodgy info is rife everywhere not just in flying forums) or interpreting the info the wrong way.

 

Good luck with it all.

 

 

[ben87r]

Just with the picture above, although good, should show the AC that uses VY above the one using VX, as it would be if represented by a period of time. I found a few like that when training and found it added to the confusion.

 

 

[facthunter]

The reduced hours in "our" certificate mean the course is kept simple® than the PPL etc where you may expect in many cases to go on to a CPL. The instructor will have to stick to a less confusing explanation for many things. than if you are going to make a career of it. This involves a question of what to tell and what to consider not necessary.

 

You should be getting a briefing that is adequate for the sequence you are going to do , Preflight. jumping in and doing it in the air is costing you money . You should also be debriefed after landing and any questions handled at that time, basically about what you did wrong and analysing it to your satisfaction.

 

You should have a text book recommended that covers any theory you need to back up your knowledge of how an aeroplane flys and why it does what it does when you do something. It doesn't mean you have to have the knowledge to be an aircraft designer . Nev

 

 

[facthunter]

Agreeing with Mozart,, That's music to my ears. Nev

 

 

[motzartmerv]

? Was it something I said?

 

 

[facthunter]

No you are innocent. Motzart is an instructor and Mozart is a fine musician. Nev

 

 

[Ada Elle]

Motz is there going to be flying at Jaspers this wednesday/friday? the airfield's been pretty deserted the last couple times I've driven past!

 

 

[motzartmerv]

Not sure Ada. The winds look pretty bad!

 

Liz is recovered from her operation now so if the wx is ok we should be :)

 

 

[diesel]

You can stall a plane at any time or attitude just by pulling the pole back. You can make a plane unstallable just by inserting a bolt so that you cannot. Hopefullt best rate of climb means that you do use ground effect and care for your engine. Best angle probably means you dont and it look bloody awfull. Chas

 

 

[Ada Elle]

How do you use ground effect with a best rate climb?

 

 

[facthunter]

Depends on your concept of it. Many who do end up flicking inverted. Does that give you a clue? Nev

 

 

[nong]

Ha ha LOL. So funny. Well done, NIbja380. Best wind up this week!