Thank you. Oh my God. Is there a table that we can carry with us when we fly around so that we know where the TA/TLs are each hour?Again thank you, for explaining the process. It does seem rather complicated. I guess my question still is why? Why is something that could be simple made so complicated? What is the possible benefit of this process?I'd never be able to figure it out.Holy cow.

Edited January 15, 201214 yr by KevinAu

That is the most confusing system. Happy the countries I fly in it is simple.

Yes, the NA system is overly complex!Welcome to "The Rest of the World!" eventually!!vololiberista

Thank you. Oh my God. Is there a table that we can carry with us when we fly around so that we know where the TA/TLs are each hour?Again thank you, for explaining the process. It does seem rather complicated. I guess my question still is why? Why is something that could be simple made so complicated? What is the possible benefit of this process?I'd never be able to figure it out.Holy cow.

Pilots don't need to know. ATC intructs them what Flight Level to fly at.The advantage is that in the UK with very congested airspace it frees up more FLs.

Yes, the NA system is overly complex!Welcome to "The Rest of the World!" eventually!!vololiberista

Vololiberista.......never mind.

Pilots don't need to know. ATC intructs them what Flight Level to fly at.The advantage is that in the UK with very congested airspace it frees up more FLs.

Well, that's a relief. Wait. What do you mean ATC instructs them what Flight Level to fly at? What if they were flying VFR? You mean you have Class A or B airspace starting at FL025 everywhere? You mean you can't just fire up your Cub and go flying around at 5500 feet without filing a flight plan or getting a clearance or paying a fee or being under positive control? What if somebody wanted to do aerobatics? We can do what we want all the way up to 17,999' msl here, no matter what the QNH setting is. I guess my confusion about how this would work stemmed from an assumption of freedom. I suppose if there was no freedom, and everything was under control by the government, then crisscrossing the TL to beneath the TA is feasible.You know, if your TA/TL was up at 18000/FL180 like ours is, you would not feel a need to "free up" a flight level or two. By bringing that border so close to the ground and shrinking the QNH area so much, you've created this artificial "congestion" problem for yourselves. We certainly don't need to do anything like that here. I certainly don't think that by "congestion" you mean the fleet of GA planes flying around down at those altitudes all over Europe? And 737s would only transit in and out of those altitudes briefly coming and going. The ironic thing is that they took all this effort to think this problem through and come up with a creative procedure to solve it, when general aviation there has pretty much been taxed, regulated, restricted and priced into oblivion already. There's nobody to actually enjoy this extra flight level they've so lovingly ginned up.

Edited January 15, 201214 yr by KevinAu

In the UK a VFR flight outside controlled airspace can occur at any altitude – subject to a minimum altitude above ground for safety reasons, and being able to see the ground under the VFR rules.The need to fly at a specified altitude or FL only occurs when vertical separation is being provided by ATC.What do you mean by “crisscrossing the TL to beneath the TA?” The TL by definition is always above the TA.Incidentally in the USA by who and how is the lowest useable FL above the TA determined?

Edited January 16, 201214 yr by mgh

In the UK a VFR flight outside controlled airspace can occur at any altitude – subject to a minimum altitude above ground for safety reasons, and being able to see the ground under the VFR rules.The need to fly at a specified altitude or FL only occurs when vertical separation is being provided by ATC.What do you mean by “crisscrossing the TL to beneath the TA?” The TL by definition is always above the TA.Incidentally in the USA by who and how is the lowest useable FL above the TA determined?

By "crisscrossing the TL to beneath the TA," what I mean is that the TL is FL025 while the TA is 3,000'. Yes, I understand when the QNH is extremely high, FL025 can translate to an MSL that is above the TA, and that is why they are capable of using a TL of FL025 while the TA is 3,000'. But 25 is a number below 30 as far as an altimeter in the cockpit is concerned. Or am I completely misunderstanding this entire thing? Is the TA being moved to below 2,500 as well when you move the TL down to FL025 from FL030?The lowest usable FL is determined by ATC in the USA. Since we only use flight levels above 18,000' in Class A airspace where everybody is under positive control, it is something that needs to be known only to the controller and only apparent to the pilots through altitude assignment. eg. "Eastern 123, Flight Level 180 is unuseable today for low altimeter, would you like 200 or 16000?"But if an aircraft is not receiving vertical separation by ATC and not in communication with any ATC while flying in the FLs, how would that pilot know where the TL is and whether or not the TL has being shifted downward if that information is known only to ATC?I don't think the shifting of your TLs downward has anything to do with European congestion. But rather, it is a procedure to overcome an inherent problem from using FLs so close to the ground. When altimetry rises, aircraft will fly higher above the ground at any given altitude when using QNE. The inherent problem arises when attempting to do something with the plane that is in relation to something fixed on the ground, such as intercepting an ILS glideslope, when your indicated altitude has no relation to the ground. As altimetry rises, and the aircraft flies higher above the ground, the proper glideslope intercept point gets shifted further and further away from the runway because the plane is higher above the ground. Therefore, as altimetry rises, the instrument landing pattern gets bigger and bigger as aircraft have to intercept the slope further and further out. Obviously, this presents problems to Approach control, who have to keep their planes within certain areas. So when the altimetry rises to a certain extreme point, enough room is opened up below the aircraft and you can shift the TL lower without impinging upon the QNH area below, and get the airplanes to fly lower and intercept closer.

Edited January 16, 201214 yr by KevinAu

Back to the OP - quite often the tower will ask if you can accept an immediate departure before you enter the active, had it happen a number of times flying out of Lanseria in Johannesburg with a Kalula 738 already established on the ILS...that is of course if the ILS was actually working and hadnt been nicked!We also had a general flying area that we would operate in below the Jo-burg TMA - we'd broadcast on 125.8 our aircraft type position, heading and altitude along with our current QNH setting - and our intentions. The normal procedure was to do this every 5 mins or so. A lot of lazy guys who wanted to hour build but couldnt be bothered to actually plan a flight would depart Lanseria and just fly there - I could never see the point in that and always planned a 3hr cross country flight to help improve my map reading and estimations and found it all very helpful. Often doing a touch and go at any number of airfields along the way - also practicing planned approaches etc - good times, I certainly do miss it all - had some great adventures out in Africa. When doing cross country we'd follow the rule of odd levels between 0-179 deg and evens 180 - 359. And depending on which area you would be flying you would report your intentions to them and request your level - you'd get an trafic advisory service from them.Also there was an area where guys could give a block of altitude in order to practice aerobatics - again same rules would apply. Somtimes in winter the temp inversion would drop the vis substancially and you would just hope that everybody was on frequency - I did have one or two incidents where I had guys visual who were obviously not on frequency - thats why eyes outside are essential.Over in the UK the airspace is a lot smaller and more conjested so its normal to broadcast your intentions on departure and make sure to report in...always remember turn, time talk. VFR obviously. London TMA used to start at about 2500 ft when departing from Biggin Hill and then it would step up as you got further away - all marked on the charts - busting it would result in a minimum of a telephone call and could get your licence suspended...

You seem to be seeing problems where none exist. What's the difference beteen ATC saying "Descend Flight Level 25" and "Descend Flight Level 35"?

You seem to be seeing problems where none exist. What's the difference beteen ATC saying "Descend Flight Level 25" and "Descend Flight Level 35"?

There's no problem with that as long as he is being told by ATC. The part I do not understand is how does a pilot know if he should have QNH or QNE set in his altimeter if 2,500 is a QNH sometimes and a QNE some other time, if he is not talking to a controller?

Edited January 16, 201214 yr by KevinAu

correct, I didn't notice that there are no winglets, I typed "MD 11 take off" on youtube search box and came up with this. :).

You're both half right. It's an MD-10 (this particular bird is an ex DC10 Series 10 converted to MD-10 standard. No centre landing gear (although the MD-11 and DC10 Series 30/40 don't HAVE to use it), a shorter fuselage and no winglets).Cheers trainspottingly, SLuggy

Edited January 17, 201214 yr by sluggy

There's no problem with that as long as he is being told by ATC. The part I do not understand is how does a pilot know if he should have QNH or QNE set in his altimeter if 2,500 is a QNH sometimes and a QNE some other time, if he is not talking to a controller?

If the pilot is flying below the TA he sets QNH on his altimeter sub-scale. As he climbs through the TA he sets 1013 and vice versa.

If the pilot is flying below the TA he sets QNH on his altimeter sub-scale. As he climbs through the TA he sets 1013 and vice versa.

That's not the confusing part. What about a pilot flying within the QNE area who is not talking with ATC? How would he know whether FL025 is there or not?

How would he know whether FL025 is there or not?

It is the pilot's responsibility to know if he is flying in controlled/uncontrolled airspace. FL's are never part of uncontrolled airspace. If he is flying in controlled airspace and hopefully qualified to do so then he is given either and altitude to fly or a FL.vololiberista