Questions

[babydeb]

Hihi

As im sure there will be people out there that have an interview lined up, and may come across questions regarding the context of the study material, I have started this thread whereby people can post questions, and kind-hearted people can help answer them

Pressure Settings
Im currently reading Air Traffic Control by Duke and I can't get my head around the following. It says that all aircrafts in the same area will be flying at the same level with synchronised altimeters. The reading given by the altimeter will only be correct when actual pressure is 1013.25; at all other pressures, the level will be more or less than the true level but whether the true setting is 1013.25 or not is irrelevant as all aircrafts are on the same setting, and any variation in actual level will be common to all.

??? Does this mean, all aircrafts, when at a certain level, set their altimeter to the pressure level of 1013.25 millibars to ensure proper separation between aircrafts?

Do we have to be as specific as this for the interview??

I apologise in advance if this is a dumb question.

Bee :eek:

[Farmer 1]

"Im currently reading Air Traffic Control by Duke and I can't get my head around the following. It says that all aircrafts in the same area will be flying at the same level with synchronised altimeters."

No, I can't get my head around that, either. All aircraft in the same area should normally have the same pressure set, but certainly not all flying at the same level.


"The reading given by the altimeter will only be correct when actual pressure is 1013.25; at all other pressures, the level will be more or less than the true level but whether the true setting is 1013.25 or not is irrelevant as all aircrafts are on the same setting, and any variation in actual level will be common to all."

Altimeters are designed and calibrated to operate in the International Standard Atmosphere, which does not exist anywhere on Earth. So, if an altimeter ever indicates the actual altitude, that is purely coincidental. However, because they are calibrated to the same, albeit fictitious ISA, then they should all be in error by the same amount. They should all tell the same lie, as it were.

The standard pressure setting should be used when flying above the transition altitude, and quadrantal or semicircular Flight Levels used, which are designed to give safe separation.

[duece19]

hehe... I just means that everyone is flying witht their altimeters set to the same datum. That the altimeter is not always (never) showing the true altitude is accounted for by setting a transition level where pilots will transition from flying on QNE (1013.25) to the airfield QNH/QFE and therefore ensure proper altitude readouts. One ofcourse needs to take the temperature deviation from ISA into account, but its normally neglected if its not alot colder than ISA.

So when flying with 1013.25 set you are flying on a Flightlevel and when on the local QNH you are flying on an Altitude.

Got it? Im crap in explaining.

cheers /duece

[Chilli Monster]

Does this mean, all aircrafts, when at a certain level, set their altimeter to the pressure level of 1013.25 millibars to ensure proper separation between aircrafts?

Yes

Altimetry 101, I'll make it as basic as possible.

Below a pre-determined altitude (normally 3000ft in the UK, but can be higher in certain areas) Pilots will set QNH - this will give altitude relative to mean sea level and is based on actual barometric pressure in that area at sea level. Above this altitude (known as the Transition Altitude) Aircraft will set the Standard Altimeter Setting of 1013.25mbs. When this is set aircraft report their level in terms of Flight Levels (6000ft = Flight 60, 12,500ft = Flight Level 125 etc etc).

Provided all aircraft are on this setting (which is NOT known as QNE, contrary to duece 19's post - this is something totally different) then you have a common datum above the Transition Altitude by which to separate them - normally by 1000ft vertically.

[duece19]

hm. now you need to tell me what QNE is... I must be getting sloppy?

[Chilli Monster]

QNE - the level indicated on an altimeter when 1013.25mb is set. Sometimes used at mountain landing strips

i.e - QNE is 16,000ft

A common misunderstanding.

[duece19]

Err... :{ It seems that Ive missed something vital during groundschool.

I shall be dusting of my books shortly

[the hunted one]

QNE - the level indicated on an altimeter when 1013.25mb is set. Sometimes used at mountain landing strips
i.e - QNE is 16,000ft
A common misunderstanding.

Just one thing missing from that one. "the level indicated on an altimeter on the ground when 1013.25mb is set"

I think! :\

[Chilli Monster]

Correct ;)

The example should have read "Strip QNE is 16,000ft" which is how it would be transmitted to an aircraft.

[babydeb]

Hmmmm, thanks everyone for that. I think i'm even more confused, which isn't any of your fault. I guess i'll have to hit the books again tonight...

Bee x :eek:

[the hunted one]

Don't worry bee, altimetry is a bit of a black art to most people! I remember being asked the old faithful at my NATS interview (long time ago now!) of "an aircraft parks at night with a QFE of 1003, the altimeter reads 0 feet. The next morning, the altimeter reads 150 feet. What is the airfield QFE?"

Well, at least it killed 15 minutes of interview! ;)

And I got it wrong! (Multiplied instead of dividing and got a stupid QFE figure)

And I got the job.

[babydeb]

Ohmigawd!! Will they ask that?? I don't even know how to calculate that!!!

Would you be so kind as to explain the calculations involved for a question like that for me??

Bee :eek:

[TATC]

Don't worry bee, altimetry is a bit of a black art to most people! I remember being asked the old faithful at my NATS interview (long time ago now!) of "an aircraft parks at night with a QFE of 1003, the altimeter reads 0 feet. The next morning, the altimeter reads 150 feet. What is the airfield QFE?"
Well, at least it killed 15 minutes of interview! ;)
And I got it wrong! (Multiplied instead of dividing and got a stupid QFE figure)
And I got the job.

You should have divided anyway-

150 /30 gives 5 millibars difference - so the QFE in the morning is 998 (I hope I worked that out correctly)

[babydeb]

im so sorry....but why are you dividing by 30?

Pls be patient with me....

Bee x :eek:

[TATC]

1 millibar difference in pressure equates to roughly 30ft on the altimeter of the aircraft

[babydeb]

o i c...... thank you!!!

[Chilli Monster]

Pressure changes (decreases) with altitude.

Common assumption (not taking into acount pressure / temperature / air density) is 1 millibar per 30ft.

[Jumbo Driver]

Don't worry bee, altimetry is a bit of a black art to most people! I remember being asked the old faithful at my NATS interview (long time ago now!) of "an aircraft parks at night with a QFE of 1003, the altimeter reads 0 feet. The next morning, the altimeter reads 150 feet. What is the airfield QFE?"
Babydeb -

With this, the Hunted One has opened a potential can of worms! There are many different ways of looking at this kind of altimetry problem and often people get confused - so before too many variations appear, you might like to try this.

Just two principles are required here - once they are understood, the answer is simple.

1 The relationship between height (feet) and pressure (millibars) is that (at sea level) 1 millibar equates to 27 feet - this is often rounded to 30 feet for simplicity. [Incidentally, as height increases the number of feet corresponding to a millibar increases steadily.]

2 As you know, the altimeter has a subscale indicating millibars which is adjusted to the setting required - i.e standard (1013.25) QNH or QFE, etc - and with an aircraft on the ground or in level flight, as you change the subscale setting, the altimeter reading will change accordingly. The important thing to remember here is that both change in the same direction - i.e. if you INCREASE the millibar subscale, the indicated altitude will also INCREASE.

Taking these two together, it should be clear that, if the altimeter is reading 150 feet on the ground, to reduce it to zero (i.e. to set it to QFE) you need to "wind off" (150 / 30) = 5 millibars. Thus, in the question above, the next morning's QFE is (1003 - 5) or 998 mb. Easy!

Hope this helps with the understanding!

[the hunted one]

You should have divided anyway-
150 /30 gives 5 millibars difference - so the QFE in the morning is 998 (I hope I worked that out correctly)

Yes, I think that's what I said. But at the time I multiplied and got a QFE of 5500 or something!!! LOL But at least I knew enough to say "that's obviously wrong" and laugh about it, and they could see how I'd worked it out and where I'd gone wrong. I think that's what they want to see. An ability to work things out logically and admit (and understand) when you go wrong.
They also showed me maps of different airfields and asked me to show them strengths and weaknesses of each airfield layout.

They also asked me about the differences between Primary and Secondary radar and the strengths and weaknesses of each.

And they gave me a scenario of different aircraft arriving at a hold, who would you make number 1, 2, 3 and 4 between a B747, a hercules, a Cessna and a helicopter or whatever.

The only other one I remember is the old trick question of where they give you a set of 4 aircraft with ETA's and ask what order they will arrive at the hold. Don't fall into the old speed trick. The estimates is the clue. Doesn't matter how slow an aircraft is, if it is 5 minutes away, it will get there before a swept-wing tornado that is 6 minutes away. It may sound obvious, but you would be amazed at how many people will say that the Tornado will get there first!

That's all the questions I remember now (apart from asking me what newspaper I read) and some topical stuff from the time about London City Airport and recommendations about flame retardent materials in aircraft cabins and passenger smokehoods, which never got adopted. To cover yourself for these type of questions, buy Flight International and another couple of aviation mags (I used Aircraft Illustrated at the time) in the run-up to your interview, that way you will know what the current "hot topic" is likely to be.

Still, not a bad memory considering my interview was in 1988! :eek:

[YourFriendlyATCO!]

Babydeb..... don't worry. They wouldn't be so mean as to ask you anything as complex as that!! I hope.

Questions such as, "Do you know how an aircraft manages to navigate?" and "What different types of Air Traffic Control are there?" were about as complex as my questions got. Hopefully they'll be the same for you

[TATC]

Babydeb..... don't worry. They wouldn't be so mean as to ask you anything as complex as that!! I hope.

Questions such as, "Do you know how an aircraft manages to navigate?" and "What different types of Air Traffic Control are there?" were about as complex as my questions got. Hopefully they'll be the same for you

I got a great question about what would happen if an aircraft crashed on touchdown , and is ther any way of keeping the airport open in these circumstance (in the scenario the airfield had 2 runways so my answer was to use the other runway unless there was damage or debris at the intersection) they changed the scenario to a single runway and the ircraft crashed short of the runway causing a lot of smoke on final approach. To this I said we could depart on the same runway and land on the other end - obviously requiring a lot of coordination with approach control

[Someone_Else]

I got a similar scenario to the above, but it was only one runway...my advice to you on that one (and any other scenarios like it) is to consider the wind!

[261A]

As this is the questions thread for ATC, I will add my question! :p

What airports/centres are under which payment band and what is the top and bottom end of the scales for each of these.

Cheers ;)

[babydeb]

TheHuntedOne - thx for all the possible questions and topics that might come up. And thx also for advising me to buy a magazine nearing the interview to get myself upto date. Wouldn't want to appear ignorant on the industry that im trying so hard to get into... >.<

YourFriendlyATCO - I hope I get straightforward questions like the ones you made... that would make them my FriendlyInterviewer >.<

TATC & SomeoneElse - for that scenario about a crash landing and the continued use of the runway, can you please explain the best answer? I've looked at my notes and found nothing in relation to that. >.<

Thanks everyone, Bee >.< :eek:

[Jumbo Driver]

TATC & SomeoneElse - for that scenario about a crash landing and the continued use of the runway, can you please explain the best answer? I've looked at my notes and found nothing in relation to that.

Babydeb,

There is another aspect to consider about the crash landing scenario you are considering.

If an airport suffers a major incident, the likelihood is (at least in the short term) that the airport fire service will be fully committed to attending the incident. At least for a while, therefore, there will be a serious degradation in the Rescue & Fire Fighting (RFF) category of the airfield. This will mean that aircraft movements (arrivals & departures) will need to be severely restricted or even suspended during the time the AFS is attending the incident. This could also be a factor if a major incident occurs near the airfield, such as a crash on final approach.

Just a thought.....

[babydeb]

Jumbo Driver - in the example of a major incident, the need for RFF, and all aircraft movements being affected, would you agree with my following thoughts?

-for the arrival flghts to either hold in a stack (if an estimated time is known) or re-route to nearby airport.
- for departures, they will just be held in a queue (but this will ultimately lead to a congested airfield..)

If this is wrong, or other alternatives are more suitable, please let me know

Bee x :eek:

[TATC]

Jumbo Driver - in the example of a major incident, the need for RFF, and all aircraft movements being affected, would you agree with my following thoughts?

-for the arrival flghts to either hold in a stack (if an estimated time is known) or re-route to nearby airport.
- for departures, they will just be held in a queue (but this will ultimately lead to a congested airfield..)

If this is wrong, or other alternatives are more suitable, please let me know

Bee x :eek:

In the short term while the level of service that can safely be provided is determined then that will be the best course of action.


Seein as aircraft prefer to take off and land into wind then the choice of runways depends on this. If there is light wind then a second runway could be used if available. If the aircraft has crashed short of the runway, and no other runway is available) then to prevent arrivals flying into any smoke created (and to avoid any search and rescue proceedings ) then they could land using the other end of the runway (i.e towards the crash) and departures could take off in the other direction (away from the crash). This would involve a lot of coordination with approach, and probably involve aircraft wrriving adn departing in groups. This is wht I said in response to the wuestion when asked it and I got through the selection process

[babydeb]

TATC - That was a very clear explanation - thank you. But does that really happen? I can't help but think that method, although is feasible, is also very risky, and like you said, requires a lot of coordination and skill. By all means, im not doubting your knowledge, but just curious about whether that is what actions are taken during a situation like that..

Furthermore, am I correct in assuming runways are oblong shaped? Thus, if an aircraft crashed short of landing, (i.e. on the oblong ) would it not block off an area for other aircraft movements? Was that a silly question? Im sorry

Bee :eek:

[Jumbo Driver]

Jumbo Driver - in the example of a major incident, the need for RFF, and all aircraft movements being affected, would you agree with my following thoughts?

-for the arrival flghts to either hold in a stack (if an estimated time is known) or re-route to nearby airport.
- for departures, they will just be held in a queue (but this will ultimately lead to a congested airfield..)

If this is wrong, or other alternatives are more suitable, please let me know

Bee x :eek:
Babydeb,

Yes, I think you are right on both points.

Arrival flights would undoubtedly be held at arrival stacks, or even earlier prior to descent (where fuel burn is less), until the situation could be assessed. Many flights these days operate with little flexibility for prolonged holding for such an event so it would be likely that a significant number would elect to divert at an early stage, rather than wait and risk the possibility that diversion airfields had "filled up".

Departing flights would clearly be held at their gates wherever possible - and in the case of an extended delay, those taxiing would return to the gate and shut down to conserve fuel and/or refuel.

[babydeb]

JumboDriver - thanks for that. Also I had not thought about the problem of fuel which makes sense because as you mentioned, not many aircrafts take delays into much consideration, thus, when faced with an RFF situation, they have to consider their fuel life - and decide whether they can hold, or need to divert.

Thanks for lighting up a bulb!! :ok:

Bee :eek:

[Gonzo]

So, seeing as how people are now giving away the 'answers', how long before NATS changes all of its interview questions?:E

And to be honest, giving the 'correct' answer was never important, it was how you arrived at a decision, and at what stage you changed your mind that we were looking at.:ok:

[babydeb]

Gonzo - no one is giving away answers since no one knows what questions will be asked!!

I am trying to prepare for my interview, and when I come across an issue I don't understand, im simply asking for advice and help from fellow ATCO who have more experience than myself.

Thats not so wrong is it?

Bee x :ugh:

[stue]

With the altimeter question, i could never understand it up untill i started flying. It was only when i saw what was actually going on with the altimeter in flight and setting it to 1013.25 etc that i understood it. It may be worth going to you local airfield and just going up and getting someone to show you how it actually happens. And the fact the on somedays FL's are not available because of the pressure on that day etc. (but thats only really for GA aircraft that hang about round the FL30/35 mark)

I found that it made it alot easier to understand when i could see what was actually happening in flight, rather than just reading it from a book.

Just a thought.

Good luck with your interview though!:ok:

[Gonzo]

No, I didn't say it was wrong. However, this thread has given me lots of clues for which questions not to ask when I conduct interviews..... :E

My post was not aimed at you, and your original question is certainly valid. As has been said, altimetry is an art, and one that causes many valid ATCOs, myself included, brain ache. :}

[Nick Falzone]

It is "wrong" if he's doing your interview, and you were christened babydebs!

[babydeb]

But thats not fair!! The point of this network is so people can speak freely and openly, and ask what they don't know and share knowledge, experience and views. And not for you to avoid the topics that are brought up, should you be in the position to interview.

Can't you look at it another way - that people, like myself, are passionate about a career as an ATCO that they want to gather as much knowledge as possible?

Im not trying to have a personal argument with you Gonzo, and im sorry if it seems that way. But we just want support, and not get knocked back...

Bee x :{

[Nick Falzone]

I will hold my hands up and confess to being a $hit stirrer, no way will you be looked on as being anything other than super enthusiastic, and I hope for your sake you weren't christened babydebs!

I think the gripe that some may have is that you are grafting, but others will just logon and benefit from all this without doing a stroke of work, and a word of advice the qfe, qne, qnh pullave above is above the head of most controllers, so don't worry too much, as gonzo said its more about being calm, collected and presenting yourself well as well read (as you can be) and being logical and someone who would be good to work with. pressure, and qne is what the college is for!!

You will benefit much more from pprune by having a day at manchester.

sorry to have wound you up!

[babydeb]

Nick - no need for apologies. Seriously. I just don't want other people, that are in the same boat as me (poor them) to be put off from asking questions, regardless of how silly they are.

Its never any harm to know too much, just don't get caught up in trying to know too much, that you may not need to know. You know? haha >.<

Bee x :eek:

[Gonzo]

Can't you look at it another way - that people, like myself, are passionate about a career as an ATCO that they want to gather as much knowledge as possible?
That is the way I look at it, even though it doesn't appear that way to you. If you ask a question to 'gather as much knowledge as possible', I will answser you to the best of my ability. I did not reply to this thread sooner regarding the altimiter question because others got there before me. I have an issue with the fact that someone who is nowhere near as passionate about becoming an ATCO as you could log on to PPRuNe, get the so-called 'correct answer', learn it verbatim, repeat it at interview, and score better than someone else who is actually more suited to becoming an ATCO.

In the 90 minute interview, I want to see how you make decisions and how quickly/slowly, how often/rarely you change your mind when presented with new information, how you think on your feet, how you handle being put under pressure, how you handle someone questioning your answers. Within the guidlines given to me by HR, that's what I'll be doing. If that means asking some of the lesser known questions, that's what I'll be doing. Perhaps I'm being selfish, but at the end of the day I might be training you in a year or so, or sat next to you. I want to know that you can do all those things I mentioned above.

But you can relax, I'm not doing any interviews this month. :O

And seriously, good luck, you have obviously prepared well for it.

edit: you bring up a good point: just don't get caught up in trying to know too much
At the interview we are testing you, not your knowledge. We give you the knowledge you need during training. Yes, please do go on as many visits as you can, get a few issues of Flight International or Aviation Week. Just don't confuse yourself!

[babydeb]

Gonzo - I guess I understand what you mean. A combination of knowledge with spontaneity, ability to think on feet and deal with changes.

And to rise up to the challenge, hoping that i would have the opportunity to be taught by you, i best be getting back to the books.

Thanks

Bee x :eek:

[Gonzo]

Got it in one, Bee!:ok:

[viva77]

Babydeb maybe you are looking at this wrongly. It is not always the right answer that is important, but how you arrive at an answer. When you visit Manchester take a tin of biscuits with you and feed the animals. Try to work out how they think. It is different to normal people, but not too hard to learn. That is part of what the interviewers are looking for.
Read back through the thread and ask youself, “Are you winding yourself up into a knot over this?” What happens when a question comes up and you haven’t asked the question on here? (because it will ) I’d think of some strategies for that if I was you, and chill a little.
However it does rather help Gonzo and his chums if you know something about the subject so keep asking the questions too, and the answers are rather fun, don’t you think?

PS I’d think about the times you’ve flown too – how long did it take, how high did you go, what did the plane look like, that sort of thing

[babydeb]

At the end of the day, im enjoying what im learning, especially so through this network, and thats gotta matter, right? hehe >.<

Ok, deep breath....im chilled!! haha >.<

Bee x:eek:

P.S. Sorry to anyone who thinks they came across a psycho....hehe >.<

[Gonzo]

P.S. Sorry to anyone who thinks they came across a psycho....hehe >.<

Why didn't you say so? That's an automatic 'in'!!! Most of us are, in one way or another......

[chiglet]

Viva,
You missed the important point.....they have to beChoccie bikkies :ok:
Seriously tho'
Any visit by [B]any[B] potential ATCO/ATSA recruit to any unit should be...in no particular order....
Interesting
Informative
Educational
Motivating
Happy with your visit
watp,iktch

[YourFriendlyATCO!]

Babyded, send me a personal message.

[BA Baracus]

Just swottin' up for my NATS interview next month. I've got a couple of questions for all you ATCOs out there (more will follow shortly no doubt):

What is the procedure if a significant chunk of metal (or heaven forbid a wheel) is found on the runway? (how do you go about identifying which aircraft it came from - and then what?)

(more for clarification/correction this one) How does air pressure affect the Atlantic track structure? (i.e. flight from London - New Yoik)
I know winds blow clockwise around an area of high pressure (in the Northern hemisphere anyhow) - does this mean that the allocated tracks for that period head off in a north-westerly direction so they take advantage of tail winds? (vice-versa for low pressure?)

Many Thanks

"I aint gettin on no plane"

[Jumbo Driver]

I'll have a crack at the answer to your second question.

Just swottin' up for my NATS interview next month. I've got a couple of questions for all you ATCOs out there (more will follow shortly no doubt):
What is the procedure if a significant chunk of metal (or heaven forbid a wheel) is found on the runway? (how do you go about identifying which aircraft it came from - and then what?)
(more for clarification/correction this one) How does air pressure affect the Atlantic track structure? (i.e. flight from London - New Yoik)
I know winds blow clockwise around an area of high pressure (in the Northern hemisphere anyhow) - does this mean that the allocated tracks for that period head off in a north-westerly direction so they take advantage of tail winds? (vice-versa for low pressure?)


Are you sitting comfortably..?

The North Atlantic (NAT) Track structure depends on the upper winds, which are in turn related to the surface pressure distribution, i.e. highs, lows, fronts, etc. However, of more significance than the positions of the highs and lows is the position of the Jet Stream. This is an upper wind, which blows from West to East across the Atlantic region and its position and strength varies daily and with the seasons. The relationship between its position and the surface pressure features is more complicated than you (or I!) need to know - it is sufficient to know that its location and strength vary daily. The wind strength at the core can be between 100kts and 200kts, so it can be a very useful tailwind flying Eastbound and flights will plan to stay well clear of its effects when Westbound.

The flow of passenger traffic across the Atlantic is "tidal", in that the majority of flights from Europe to USA/Canada will take place during the day and the return flights from USA/Canada to Europe are overnight. To deal with this efficiently, a NAT Track structure is prepared by Shanwick (the Oceanic ATCC for the UK side of the NAT region). This structure provides typically six tracks from East to West for daytime use and six from West to East for overnight. They are like moveable airways, each having allocated levels for use and providing lateral separation from adjacent tracks.

All tracks will be prepared using the forecast wind to provide "minimum time" between their Oceanic entry/exit points of the Atlantic crossing at cruising levels, at the same time as providing the necessary lateral separation. This will depend on the pressure situation across the whole Atlantic region and not just the local features near to UK. The location of the Eastbound tracks will usually be very different from the Westbound tracks, as the Eastbounds will be seeking maximum tailwinds (W-E) and the Westbounds seeking minimum headwinds. The entry/exit points are fixed and the track structure is planned between them to give the best "minimum time" tracks according to the forecast winds.

This is probably far more than you need to know at this stage - but I hope it helps with the understanding and planning for your interviews.

Good luck.

[greek-freak]

Just to add something to the reliability of the jetstream.
It is such a constant phenomenon that most airlines include the
tailwind in their flight plans, i.e. the official eastward flying times in the timetables are typically 1-2 hours shorter than on the westbound flights.

[Bern Oulli]

Babydeb, and anyone else strggling with altimetery, go to this site (http://www.flashsim.com/pubDown/f5alt/altimeter.html), where you can play with an interactive altimeter. Unusually for altimeters, the sub-scale is in both millibars (hectopascals to the rest of Europe), and in inches of mercury (as per the US of A).
Now you can explore the more devious questions like:
You are flying at FL60, outside controlled airspace (6,000ft with 1013mb set). You are approaching a Danger Area with a top limit of 5,500ft. The Regional (local) QNH is 996mb. Will you be above the top of the Danger Area or not? By how much will you be above or below the top? Assume 1mb=30ft.
Try working it out on paper first, then check with the interactive altimeter.

[BA Baracus]

Just tried working it out on paper and wondered if anyone could correct my thinking please or tel me if Im on the right lines? Be kind - Im just learning.

Answer - 10ft below the top of the danger area.

I worked this out in a rather complicated way, but have thought about it again:
The difference in height is 500ft. However, the difference in mb is 17mb. Given the 30ft for every mb, this works out at 510ft. So if I were to fly on the SPS setting into the danger area with a QNH of 996mb, then although my altimeter would still read 6,000ft, I would actually only be at 5490 feet due to the pressure variations.

[Bern Oulli]

Spot on. OK, so you can skip the altimetry lessons then!

[BOAC]

That is a neat little site!:ok:

[Lon More]

Many years since I worked at Prestwick but try a Google on NATS tracks.The tracks are determined by a twice daily conference between the centres involved.

Re debris.There should be a part number on most bits and a check with the maintenance staff of the airlines using the runway since the last inspection should provide an answer.The info can then be passed to the possible flight(s) concerned either via company freq. or via ATC.

[BA Baracus]

Thanks for the replies.

Just a quick question. At area centres, orange strip holders = eastbound aircraft, blue = westbound aircraft. What's the case at Aerodrome - which colour are departures and which for arrivals?

Thanks


" I aint gettin' on no plane"

[Gonzo]

It varies. At Heathrow, we have blue for outbound, and orange for inbound.

At Heathrow Approach at TC, they have different coloured holders for the different wake vortex categories.