The Fire one. Don't ask why.....

I'll bite. Why?

I don't know :) I just have it on good authority that student recollection is not correct - it will no doubt be in the CTKI circular anyway.

Heard some rumours milling about that grid nav is no longer appearing in Ops tests. It's still in the L.Os though. Anyone able to confirm/dispel the rumour?

thanks Paco.

A student reported that they got a Grid Nav in a recent OPs exam. Another also reported 7 Polar Stereo questions in GN.

Who writes this nonsense?
 

Is it possible, Paco, that you wrote a question along these lines, submitted it, then it went through the full proof (sarcasm) checking process and was changed in some way, which then brought doubt in to the answer?

There gets a point where for instance the fire question needs to be released as it was given to the student, confirmed by the student that it was in deed given that way, and if it is a bad question, the writer, the checkers and the authority should be held accountable.

I'm sure a great many authority bods think they are making the skies safer with these moves, but I bet if we ran any of them who are still flying through the same test they would fall flat on their face. Does that mean they should surrender their licence because they are not safe?

It is farcical to learn these regulations when they could change the day after a student takes an exams.

Better that the student be given a set of questions and the regulation and told to go find the answer. And require him to get 100%.

It's not mine :)

Anything is possible, of course, as once it has been checked against the methodology (and the girls who do it are sharp cookies) and technically reviewed, I shouldn't see it again. All I can say is that I get questions sent back for a typo which could easily be done by EASA, and each question has a full audit trail of comments, so it is unlikely.

I hear you about regulations, but you have to draw a line somewhere - helicopter pilots are still on JAR OPS, at least until very recently. The trick there is not to be too specific.

Re your last comment - some authorities don't have the facilities for open book - in flight planning, for example, the Jep stuff will be in the question now, rather than using the book. I don't see the problem, but there apparently is one. In this respect, EASA don't seem to be able to enforce rules - instead they leave their interpretation to the local authority, which means we are no better off than under JAA.

The German system allows questions that require a typed in answer that must be correct - a good move in my opinion.

Coriolis effect
 

Hi

I'm studying for exams and understand the Coriolis effect. However, I don't understand why it would apply when travelling just east to west or vice versa (bit I'm pointing to in the pic deflecting right). Surely the ground underneath rotates at the same speed relative to the wind the whole time when it's just east to west (or vice versa). I understand that if travelling north as in '2' below, the wind would be moving faster than the ground underneath it.

Can anyone explain please?

I think you are correct, it doesn't, and you first diagram is incorrect. Where is it from?

Imagine we stop the earth's rotation, just to illustrate how objects moving towards east or west behave.

Imagine you could shoot a magic bullet, one that keeps moving forever at the same speed and height above earth's surface.

If you shoot the bullet towards the east, it will NOT circle the earth at the same latitude. It will start going towards equator.

The reason is that all such movement will follow a great circle. Hence, there is always a north / south movement, unless you are on the equator.

Imagine standing on the north pole. You walk a hundred yards in any direction (south). You shoot your magic bullet to the east. You wouldn't expect it to circle the pole, and hit you in the back a second later, no ? It will fly all the way towards the south pole, pass it at a hundred yards, and then back.

Interesting, and it makes me question what I thought I knew. But if your analogy is correct, Gargleblaster, a bullet fired in a westerly direction in the northern hemishphere would deflect to the south as well, ie to the left. But this is the opposite of how the coriolis force works.

While I think about it I have grabbed a bit of Wiki that seems to support the idea that coriolis acceleration depends on the direction of movement:

In non-vector terms: at a given rate of rotation of the observer, the magnitude of the Coriolis acceleration of the object is proportional to the velocity of the object and also to the sine of the angle between the direction of movement of the object and the axis of rotation.

https://en.wikipedia.org/wiki/Coriolis_force (the 'formula' section)

Thanks for the responses.

Alex, it's just from google images but I've seen plenty of other diagrams saying the same thing.

Gargle, by all movement 'follows' the great circle, do you mean all movement is drawn to the great circle (equator)? If so, why? And, as Alex said, wouldn't that mean in your analogy shooting west, Coriolis would deflect it to the left? If so, that is contrary to the notion that Coriolis always deflects right in northern hemisphere.

For your analogy, I don't know what I'd expect, but circling the north pole and hitting me doesn't feel any more 'wrong' than flying to the south pole, passing at a hundred yards and coming back.

Any feedback from recent exams regarding Performance (A) and flight planning?

Re the Coriolis thing - I'm not sure if this will make it any clearer, but after much scratching of the head (it was a 2-Columbo problem).......

There is no Coriolis at the Equator within about 20 degrees either side, but elsewhere, when going East, you are moving with the Earth, so your velocity is greater (similar to having a tailwind). Of course, going the other way, you will be going against the Earth's rotation, and will be slower.

You are accelerating, in that the nose is going downwards to maintain your altitude, so there is an element of centrifugal force involved, changing its value with the changes in acceleration mentioned above - enough to cause a deflection towards the Equator when moving faster than the Earth, i.e. West to East, or towards the Pole when travelling slower than the earth, or East To West. Either way, the deflection is to the right.

The centrifugal force is balance by gravity when you are at rest, but once you start moving, it changes.

Back to Columbo...

Instruments Feedback
 

In order to know in which mode the auto-throttles are engaged, the crew will check the:


https://dub129.mail.live.com/Handler...2foption-A.pngPFD (Primary Flight Display)<<<<<<<<<<<<<<


https://dub129.mail.live.com/Handler...2foption-B.pngTCC (Thrust Control Computer).


https://dub129.mail.live.com/Handler...2foption-C.pngThrottles position.


https://dub129.mail.live.com/Handler...2foption-D.pngND (Navigation Display).

In my exam the question was worded exactly the same but PFD (Primary flight Display) had been Replaced with FMA (Flight Mode Annunciator) I.e in the exam it was represented like this :-

In order to know in which mode the auto-throttles are engaged, the crew will check the:


https://dub129.mail.live.com/Handler...2foption-A.pngFMA (Flight Mode Annunciator)<<<<<<<<<<<<<<<<<<<<<<<


https://dub129.mail.live.com/Handler...2foption-B.pngTCC (Thrust Control Computer).


https://dub129.mail.live.com/Handler...2foption-C.pngThrottles position.


https://dub129.mail.live.com/Handler...2foption-D.pngND (Navigation Display).

Coriolis again
 

It is indeed a 'two Columbo' problem. Having given it much thought and googling I reverse my earlier position and agree that the diagram is correct, when travelling due east or west there is a coriolis force to the right. Paco's explanation above refers to an element of upward acceleration travelling east from which the coriolis force derives, which is I think correct. The mathematical approach on Wiki under 'rotating sphere' appears conclusive.

Air Law
 

Hi, I need to review these subject areas for my a repeat AL exam, not quite sure which areas these relate to, anyone know? Thanks.

010.01.04.01
010.02.01.00
010.05.03.00
010.05.04.00
010.05.06.00
010.06.04.02
010.06.06.02
010.06.08.01
010.07.02.02
010.07.02.13
010.08.04.03
010.09.08.02
010.10.02.03
010.12.06.00

010.01.04.01
010.02.01.00
010.05.03.00
010.05.04.00
010.05.06.00
010.06.04.02
010.06.06.02
010.06.08.01
010.07.02.02
010.07.02.13
010.08.04.03
010.09.08.02
010.10.02.03
010.12.06.00

try these



http://www.lba.de/SharedDocs/Downloa...cationFile&v=2

Thanks Alex and Paco. Unfortunately, your explanations still don't make sense but I will trust you. I suspect if I was walked through the maths in the wiki link it would make sense, but I don't have the ability to do it myself.