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-   -   ATPL theory questions (https://www.pprune.org/professional-pilot-training-includes-ground-studies/455580-atpl-theory-questions.html)

RedBullGaveMeWings 18th Feb 2017 22:16

I am mainly using Aviation Exam on Exhaustive mode. I will also start integrating with Bristol QB, which is very good if you are sitting your exams under the UK CAA.

RedBullGaveMeWings 19th Feb 2017 17:18

Binary code is no mistery to me and I have some experience in programming, but curiosity strikes me now... Why is EASA asking to convert a binary code?

paco 19th Feb 2017 18:22

It's a throwback from the days when you were expected to fix your own radios in the jungle......

KayPam 21st Feb 2017 22:53

Hello

I just started performance
Could someone please confirm that the entire CAP698 document will be available during the exam ?
My book says things like : "this is included in CAP698 so it does not need to be learnt"

Thanks

Alex Whittingham 22nd Feb 2017 08:39

That would not be so in the UK. The UK CAA used to allow you to take the whole CAP in but this has not been the case for some while, now you only get an 'Annex' showing the relevant graph. Our students, therefore, do need to learn the various formulae and conversion factors. If you are sitting the exam in France you should ask the DGAC what their rules are, or ask your ATO.

RedBullGaveMeWings 22nd Feb 2017 13:49

I am a bit confused about the following question:

For a given IAS and angle of aileron deflection, increasing altitude will:

A) increase the rate of roll [correct answer]
B) increase the rate of turn
C) reduce the rate of turn
D) reduce the rate of roll
Clearly A is correct because aerodynamic damping is less at high altitude, however, constant IAS means an increasing TAS which also reduces rate of turn.

What does examiner really want to ask here? I see two correct answers.

Alex Whittingham 22nd Feb 2017 14:43

Not being an aerodynamicist I'd have gone for (D). I remember exactly this exercise in the Hawk when an instructor tried to convince me that the highest rate of roll occurred at altitude, when it clearly didn't. On landing I found the reference in the manual which said the optimum rate of roll was at sea level. I always assumed he had written the lesson down incorrectly on his knee pad, but who knows.

The clue might be in the 'constant IAS' phrase, you get better roll rates at high IAS at sea level but you can't make those high IAS's at height because of Mach effects. I will wait for an aerodynamics expert...

KayPam 22nd Feb 2017 21:13

Alex : thanks

RBGMW : You might want to derive a simplified flight mechanics formula
The rolling moment equation is (simplified)
Inertia*φ'' =(Cldl*dl + Clp pb/2v) * QSb

Any answer to a rolling question is behind this equation.
Then you just have to interpret your question.
Are we talking about the maximum achievable rate of roll ?
If yes, then phi''=0 when max rate of roll is reached and :
Cldl * dlmax = Clp pmax*b/2V

Cldl, dlmax, Clp, b are constant.
So pmax will increase if V will increase. At constant IAS, V will increase with altitude

The rate of turn is unrelated to the angle of aileron deflection.
Depending on the aircraft, you will be in a steady turn with aileron undeflected or deflected in any direction (towards the turn, outwards the turn, more directions if they existed)

So I'd go A

Alex Whittingham 22nd Feb 2017 21:20

Thanks KayPam, that in a nutshell, is why I don't teach principles of flight! will work through it slowly tomorrow.

keith williams 23rd Feb 2017 07:36

This question is intended to be answered by ATPL candidates, it should be possible to solve it without going beyond the ATPL syllabus.

The question is an old one (probably 16 or 17 years old), so it really should be bread and butter stuff for ATPL instructors and students.

Let’s start by looking at a few things which ATPL students should know:

1. Rolling motions are generated by the aerodynamic forces acting on deflected ailerons.

2. The magnitude of these aerodynamic forces increases with increasing angle of deflection and with
increasing dynamic pressure.

3. If we climb at constant IAS the dynamic pressure will remain approximately constant, so the rolling
forces generated by any given aileron deflection angle should also be approximately constant.

4. Rolling motions are opposed by aerodynamic damping.

5. Aerodynamic damping decreases as TAS increases.

6. Climbing at constant IAS causes the TAS to increase.

7. Radius of turn = TAS squared / g Tan AOB.

8. Rate of Turn = g Tan AOB / TAS.

9. Under normal circumstances, keeping the ailerons deflected will cause continuous
rolling motion, but will not produce a constant angle of bank.

Looking at statements 1, 2, 3, 4 5 and 6, we should see that climbing at constant IAS will cause roll rates at any given aileron deflection to increase (Option A).

Looking at statements 7, 8 and 9 we should see that aileron deflection does not control the rate of turn or radius of turn, so options B and C are incorrect.

At this point we may be tempted to argue that “if we fly high enough our maximum IAS will be reduced, so our maximum roll rate will be reduced. But the question specified “ constant IAS” so this excludes any altitude at which it is not possible to maintain a constant IAS. So option D is incorrect.

It is a well known fact that many of the questions used in these exams are defective, but candidates must take care to avoid being too eager to simply tell themselves “Oh this is just another duff question”. Such eagerness is likely to cause them to raise large numbers of appeals, which are subsequently rejected. If they have paid insufficient attention to selecting the best option, the result is likely to be an examination failure. Whenever a candidate thinks that two or more options are correct, their first action should be to look very carefully at why they think each option is correct.

Alex Whittingham 23rd Feb 2017 09:45

Thank you Keith. I suspect that the clue to my misunderstanding is indeed the IAS thing for when comparing roll rates at 420KT IAS/TAS at sea level with roll rates at 200KT IAS/420KT TAS at height the sea level roll rate would win out. Hence the statement in the flight manual that for a particular aircraft (albeit a reasonably fast little jet) the optimum rate of roll is at high IAS at sea level.

oggers 23rd Feb 2017 10:46

I agree that the correct answer is A.

Given that IAS and aileron deflection are constant it follows that:
The dynamic pressure is constant and therefore roll moment due to aileron deflection is constant.
Given that altitude increased (with IAS constant) it follows that:
TAS increased.
Steady state roll rate is achieved when roll moment is in equilibium with roll damping. And for a given roll rate, roll damping would be less at higher TAS. Therefore roll will go to a higher rate before equilibrium is reached.

As RedBull says, answer C is also tempting because the higher TAS would result in a reduced rate of turn as well. But the question does not specify any angle of bank or even that the aircraft is turning. It could be an aileron roll. So based on the information available in the question there is only one answer that is definitely correct, and that is A.

RedBullGaveMeWings 23rd Feb 2017 11:20

Now it's crystal clear, thanks Keith.

KayPam 4th Mar 2017 20:04

Could someone please explain ?

https://i.gyazo.com/76c101cae12e601f...777c79108f.png

Obviously, V1 can't be lower than Vmcg.
But who says one has to choose a balanced V1 ?

In this case, one would just increase V1 above the balanced value. As a result, the ASD and ASDR would increase above the one engine out takeoff distance.

Anyone has an explanation in favor of the green answer ?

keith williams 5th Mar 2017 09:43

This question has been around for many years, and I recall appealing it as long ago as 2007.

The UK CAA examiners' answer at that time was "Ah but you must assume that the aircraft is taking-off at it's field limited take-off mass, so there is no space available to increase ASDR" When I pointed out that nothing in the question indicated it being a field limited take-off, there was no convincing reply. I believe that most of the schools appealed the same question and got the same response. This was quite common at the time.

KayPam 6th Mar 2017 14:34

Thanks Keith !

I will be passing (not taking :p) instruments, meteorology, performance and mass and balance next week.
My books were read and all AvExam questions are answered, so my method requirements are met

However, for the next subjects to come, I'm not so sure if I should still apply the same method...
Next set of exams will be flight planning, principles of flight, and aircraft general knowledge.
For AGK, i'm pretty sure it's best to read the entire books and to do all the questions.
But flight planning seems really easy - just time consuming
And POF is sort of in the middle I think.*

I am doing the flight planning questions right now, without having ever opened the books, and I find myself answering correctly to 90-100% of the available questions..
Overall there are just the same calculations to do over and over again with few variations and little specific knowledge to have (like what are the different fuel quantities required, how long before a flight should one file a flight plan and that's pretty much all..), and then careful thinking and calculations will guarantee the correct answer..

I calculated I would be spending like 15 hours just answering AviationExam questions on this topic...

Is it really necessary to see all avexam questions ? Could there be any surprise question like there could be in a subject like AGK, instruments or meteorology ?

Fellow ATPL students, does your method include answering all the questions on the question bank ?


*Note that I'm currently working for airbus flight testing department so I'm well used to calculations and the sort of tables/graph they provide in this 33-test.

Following subjects will be human factor, gen nav and radio nav.
Will it be beneficial to have seen all the questions on these subjects ? I believe it could very well be so.

By the way, here is an advice for all distance and heading calculations of flight planning :
Instead of looking up the points and measuring your map distance then measure it against a meridian to have ground distances, like a galley slave would do, simply use the approximate or exact formula for distance computation based on the coordinates (which are given in the question) :
Pythagore (assumes earth is flat, which works very well for distances under 1000-2000 km) : 1 degree of latitude is 60nm and 1 degree of longitude is 60*cos(latitude)nm
Or, for very long distances :
D=Rt*acos(cos(lat1)cos(lat2)*cos(lon1-lon2)+sin(lon1)*sin(lon2))
Where Rt is your earth radius in the chosen unit.
(This formula is very easy to remember, just remember lat lon then 1 2, 1 2, 1 2, works just as well with 2 1, 2 1, 2 1)
And simple trigonometry (in the plane!) to get the true direction.

paco 7th Mar 2017 06:16

Calculations are often easier than measurements. You can do such triangles on the front face of the Jeppesen CR-3.

And with the ED-6, remember that it is a 515000 not a 500000, so use the scale marker on the map if you do measure things.

GcitoG 9th Mar 2017 04:49

Question bank
 
Hi y'all

I have a job interview next week and have been practising with Prepware FAA ATP 2017 question bank. Chances are the airline has not update theirs yet, so my question goes like this: "Are there many changes on the new bank so that I can know what to expect?"

oggers 9th Mar 2017 07:55

KP


Anyone has an explanation in favor of the green answer ?
Yes:

"If the balanced value of V1 is found to be lower than Vmcg, the take-off is not permitted"

...is a correct statement.

KayPam 9th Mar 2017 21:13

Sorry but I don't see the point.

V1 must be higher than Vmcg is a correct statement.

If the balanced value of V1 is lower than Vmcg, just increase V1 up to Vmcg !!
Then if the ASD is still within the limits of the runway (including required margins) then you can takeoff !


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