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".

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?

I think you have mixed the terminology and confused yourself.Best angle of climb is done usually at a lower airspeed but higher angle of attack( nose high) to clear obstacles but gives a lower rate of climb eg500ft/min which may only result in 1.5kms to arrive at 1000ft but take 2 mins. this is used to clear obstacles.

Best rate is done at higher airspeed & will give you altitude faster but over a greater distance on the ground eg 700ft/min& 2 km to get to 1000ft(about 1.5 mins ) just as an example

 

So best angle is in relation to the ground, best rate in relation to time.

Where as a best rate of climb will produce a climb that is at a lower angle of attack and hence a lower attitude, will cover more horizontal distance, and will reach the similar altitude in the same time because it is doing so at a higher speed.

If they were to complete both these two climbs, at the same speed and the same time interval, the best angle of climb would clearly gain a larger amount in altitude Correct?

I think im just going to have to accept it for what it is at this stage. For some reason i just cant grasp it.

If there doing it at the same speeds, the best angle of climb will have a higher attitude, will cover less ground distance, but reach the same height. Where as the best rate of climb will have a lower nose attitude, and cover more horizontal distance, which would be better for fuel encomy. Where as the best rate would be more appropriate for takes off where there are obstacles at the end of the runway.

So generally speaking, is it preferred to use a best rate of climb, since your covering more ground distance which would be mean you going to save time (fuel) and because you have better visibility because of the lower nose attitude.

I just dont understand how they can be the same altitude after the one min, and not have different speeds. If they had different speeds, that would make sense, what is the difference between them. Sorry if im being a pain.

Rate of climb would be the same. You are ascending through a parcel of air which is also moving relative to the ground.So if the parcel is moving backwards from an obstacle, you would clear an obstacle quicker with the higher headwind- the ANGLE of climb would be greater the greater the headwind.

 

But you won't have ascended any quicker. The parcel is being blown backwards away from the obstacle with a headwind (and you with it). It decreases your horizontal speed (ground speed).

 

Ground speed will never affect climb RATE, but it will change the ANGLE you climb at.

 

I think you also want to call it GS (ground speed) not GAS. Ground speed is not an air speed. Airspeed is really a pressure - technically the dynamic pressure - the pressure of the wind hitting your wing as you push against it.

 

We travel through a parcel of air, hitting it, that's IAS. The pressure is being directed downwards - that's how we are flying!

 

You've got me thinking now. I found this which shows you what your ASI is actually showing you. http://www.rst-engr.com/rst/articles/KP89JUL.pdf

Let me confirm.

The rate of climb is the height gained over a certain time interval. Say if we had a headwind, the ground speed is going to be less. We are going to not travel as far horizontally as opposed to no wind. Is the actual speed at which you climb less? Hence why we only climb to the same/similar altitude as a best rate of climb with no wind, which would cover a greater horizontal distance, but do so because it is at a greater speed?

Yes.. stalling speed increases with actual weight . or with a dynamic situation such as a banked turn. where you feel an extra"G" load The stalling angle for a given airfoil stays the same. If you modify the airfoil with Ice accretion or slots and flaps the stall angle changes because the airfoil has changed. If you have ice on the wing for example, the stall speed may increase markedly and lift will be reduced and drag increased. Nev

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?

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?

Your first question:You are flying through a parcel of air, the parcel of air is moving across the ground.

 

No matter how fast (or in what direction) the parcel of air is moving across the ground, you are moving through that parcel of air at the same speed and direction.

 

So you will climb through this parcel of air the same no matter how it is moving in relation to the ground.

 

If the parcel of air was moving downwards vertically then yes, your rate of climb *relative to the ground* will be affected - you're still climbing through the parcel of air at the same rate.

 

If the parcel of air is moving forwards (tailwind) your ANGLE of climb *relative to the ground* will be smaller. but again you're climbing through the parcel of air at just the same over time. The RATE of climb is still the same (height gained overtime), but the prevailing winds can affect your ANGLE of climb. A headwind would increase your angle of climb (but not the RATE).

Can somebody explain why the best rate of climb is uneffected by a headwind.

I understand that the best rate of climb will provide the greatest vertical distance over minimal time, and will generally cover greater ground distance at a higher speed and lower attitude then that of the best angle of climb which will provide the greatest vertical distance over the minimal ground distance, and generally have a slower speed and higher attitude. And that the best angle of attack is effected by the headwind, which would produce a greater attitude, but why is the best rate of climb uneffected by a headwind and is the same with or without a wind (same vertical distance).

Also, can someone please explain the stalling angle of attack/speed. The definition in my book is "At the stalling speed, the stalling angle of attack is required to produce the necessary lift. Any further increase in angle of attack will result in less lift but more drag. It is important to note that it is actually the angle of attack that causes the stall".

So correct me if im wrong:

I can fly at 60 knots, and say the aircraft, at this speed, will have a stalling angle of attack of say 16 degrees (just random). Anything above this angle will result in a stall.

Or i can fly at 50 knots, and say the aircraft, at this speed, will have a stalling angle which is less then 16 degrees

And vice versa.

So essentially, the angle of attack for a stall is dependent on the IAS of the aircraft?

How is this effected by weight?

Naturally, by increasing the weight, a greater amount of lift is required.

For the aircraft to fly at an angle of say 16 degrees, the IAS is going to be have to be greater then the original 60 knots. So basically the increase in weight, will require a greater speed to fly at the angle of attack to maintain lift, which will create the stall if gone beyond this angle or if the airspeed is lowered beyond this new airspeed.

Ive kind of confused my self.

Had my first lesson today! Now ive got forms to fill out and logged my first hour in a Cessna 172. Covered a bit of everything, mainly focusing on keeping level flight, trimming it and getting a feel for it all! Crazy pushing the throttle all the way in, pull straight back, flaps 30 degrees and just climbing at 40 odd knots! Loved it! Planning on getting lessons every 3 weeks. Hardest thing was taxing with the whole rudder and rocking the foot for the brake. Zig zagging down the runway, haha. Thanks for all the advice guys.

Thanks for all the feed back guys. Deffs keeping year 12 a priority! Just keep second guessing about go ahead with it all. Just generally speaking, im looking at flying out of latrobe, and saw on their website that there a scholarship opportunities. Generally speaking, how often are these given out, to what amounts, etc? Does a young kid like me have a chance of scoring one. This is a major point of second guessing it all. While my family is paying for a majority of it, ive agreed to chip in 1-2000 dollars to help. Which is a considerable amount considering i also ahve to put money towards a car and pay for fuel, etc.

I think you'll find if you read thru that thread, it has a fair amount of info.in a nutshell - RAAus is the adminstrative body for issuing the RAAus certs, which restrict you to a 2 seat, single engine plane less than 600 kg, and no access to controlled airspace, and on the RAAus registry. wtih the proper endorsements, that still allows you 1 passenger and access to 95% of the country. CASA adminsters general aviation (GA) and issues the RPL, which is a step on the way to the Private Pilot Licence. It allows more or less the same, but in a VH- registered plane up to 1500 kg, and allows access into controlled airspace.

 

They are roughly equivalent, but separate. The skills and terminology are (mostly) the same and if you have one, you can easily transfer to get the other (options!)

Edit: Had a look on the website and doesnt look like the airport i train at is on there (in terms of the actual school).

Hahaha, thanks.

Ive been having a look on the forums and i see two different licences like the forum title below. Would someone be able to elaborate?

RA-Aus RPC to CASA RPL

I defiantly have a passion for it. And its my dream, to get a good job so i can fund my flying, eventually working towards IFR ratings, etc. And one day, maybe my own plane ;) Im booked in for another introductory flight on saturday to have a chat and obviously go up for a fly. Im not too concerned about school getting in the way. Im currently doing well at it, and taking a lesson once every three weeks before work isnt going to be to demanding or take to much time. In terms of theory, i can always find time throughout the day such as on the bus and at break at school to complete some of it. After all, if you enjoy learning it and have a passion for it, it isnt really studying/work is it! Worst comes to worst, during exam time if it gets to demanding i can just call it off temporary. Im hoping to get a majority of the hours out of the way during the 2 to 3 month summer holidays i have before i start (hopefully) university. I think its full steam ahead! Cant wait until Saturday! Thanks guys for all the advice, glad to be part of the forums!

Thanks for the replys guys! Much appreciated. Im doing fine in school, and would consider my self quite strong in maths and the sciences (physics) its just the score i want requires a fair bit of time commitment (engineering). I thought about doing it at the end of the year in the holidays but wasnt sure how good it would be to cram it all in kind of thing. But over a two or so month break its probably not that bad. Keep in mind i work in retail also so the summer holidays are crazy for me. If i was to do it during the year, how often would you recommend doing it? I usually work once a week on a sunday afternoon for a couple of hours, so id possibly try and squeeze my flying in that sunday morning, so then i can work for the rest of the day, and just take the day of school work completely. That was my plan. Im glad the theory is quite simple though, and im sure ill enjoy the read anyway. Can anyone provide a sample of a question like that found on the recreational pre-solo exam? And also, id be training out of a uncontrolled airspace. If i was to then go flying at a different airport, say Morabbin, is there a strong learning curve in dealing with ATC, or is the whole recreational pilots liscence requirment that you only fly within the area you trained in? (I remeber reading that somewhere but not sure if its true)

Hi,

First post. Im currently 17 turning 18 in a couple of months. I have a passion for aviation, have had various model aircraft throughout my teenage years, and generally just love hoping into a big metal tube and whizzing past in the sky. Ive been toying with the idea of getting my recreational pilots license for a while, but only know have kind of thought what have i got to loose. THere was a lot holding me back in the past. I guess my main question is how much is involved, theory wise in getting your recreational pilots licence in Australia? How mnay hours should i being putting towards it per a week (maximum)? I raise this question because im currently in my last year of schooling. It takes a lot of time, and i also work a part time job. Ideally id getting a flying lesson in every three weeks, possibly every fortnight. Which in itself isnt that time consuming. The theory is my major concern. Can anyone elaborate on the difficulty, time and contents of the theory involved? Im planning on timing it such that im ready to take the theory exam, have my medical done, and be ready to solo after im complete exams for school. Around the November, December time frame before i start univeristy. THanks.