A bust is if you are within CAS shown on the VFR chart.
@Peter, what you say would make sense to me of one could be assured that any plane trying to avoid entrance to a given airspace block without an ATC clearance would be on the controlling agencies altimeter setting. As I recall it’s possible in the UK to have aircraft in the same low altitude position on at least three different altimeter settings: local QNH, RPS and the standard altimeter setting that’s used above ridiculously low TAs. That is if you ignore QFE. GPS altitude is another (illegitimate) possibility apparently used by some who are baffled by the above, but its obviously not in actuality applicable to any airspace, anywhere.
This is a great example of regulatory entropy and its effects, and it’s hard to imagine how anyone would expect it to work in a terminal area. The theatrical and overdone way violations are handled by UK CAA doesn’t help either.
How am I confused? (It’s a genuine question)
RPS is completely useless and needs to be avoided. This is a UK-only thing.
QFE is an ex RAF thing and is arguably useless.
QNH and 1013 are to be used for avoiding CAS bases defined as AMSL or FL respectively – that is standard.
The whole of Europe has low FLs while the US has FL (altimeter setting 1013) at/above 18000ft. Europe did look at that some years ago but could not agree.
I’d maintain that given the four possible CAA-approved options for altimeter setting in the same place, complicated and confusing factors like low TA do matter in creating consistent Class A avoidance. If TA were above all terminal airspace there would at least be one less altimeter setting option. My take-away from the ‘email from the CAA’ video and post 98 is that the whole system is an antiquated mess and that in response people are trying to create an automated tool to handle the chaos, using GPS-based navigation, a solution that doesn’t work.
Alpha_Floor wrote:
I have to say I am a bit tired of the “politically correct” editorial line of these videos:John Hunt is the perfect ambassador for the British CAA. His videos are extremely well made, but at the same time, always searching for pilot errors he or his guests make. Don’t get me wrong: We all make mistakes, and it’s great that he motivates an open failure culture, but John seems to love to go down the walk of shame twice. The fact that his guest states “It’s only my fault, 100%” multiple times, is partly painful to watch. In this video, there was not a single word of criticism on the crazy southern UK airspace or marginal ATC services.
- If you bust airspace it’s 100% your fault, ALWAYS.
- You deserve to be “shame-walked” naked all the way down the High Streat while angry peasants spit on you.
- Be thankful you got to keep your licence!
Peter wrote:
A bust is if you are within CAS shown on the VFR chart. Simple! Nothing to do with TA or TL or semi rules.
Indeed. I’m still hoping for a clarification from @hazek about this:
hazek wrote:
if you have not passed the transition altitude, then by definition you can’t be at FL55. So how can you possibly bust a level that you aren’t at? If the transition altitude is 4500’ and I am flying 4500’ at the by ATC provided QNH then I am at ALTITUDE 4500’. I can’t be at ALTITUDE 4500’ and at the same time at FL55, no matter the air pressure.
So once again, if the lower limit of the CTA is FL55 (say), the TA is 4500’ (say) and the QNH is 970 (say). Do you or do you not bust the CTA when flying at 4500’ on the QNH? If not, at what level do you actual infringe?
Routing NE near CPT OCAS the IFR FL would be FL50, and on a high pressure day you might bust the floor of Q63 at A5,500’. In the UK if you are not under a TMA the standard TA is A3,000’. Beneath the London TMA the transition level out west might be FL75, so am wondering whether the convention in the UK is to use a FL as a transition level when it isn’t the standard TA of altitude 3,000’ ? This might answer the question in the UK? It is part of the IR training to understand when there is a risk of conflict either on a high pressure day (FL to Altitude), or on a low pressure day (altitude to FL). As the standard TA outside CAS is relatively low, therefore the main scenario is FL on a high pressure day, with an altitude floor for CAS. This sometimes even catches out ATC when on a FL vector.
In France the general TA/TL is 3000’ AMSL or 1000’ AGL whichever is the highest.
This does not apply, necessarily in TMAs or CTAs etc. There there is a published TA/TL or it will say it changes and will be given by ATS. To be honest whilst we take note of using flight levels and the semi circular rule above 3000’ OCAS we tend to ignore it in the controlled environment. That is simply because a controller will say eg “climb to level 100” or whatever. At that point I and most others I fly with put, 1013 on the altimeter. If we have 2 altimeters we will keep one on QNH. In descent it is simply the reverse the controller says “descend 5000 ft QNH 1008”. We stick that in the altitude window and descend to 5000ft. There is no need in CAS to know the TA/TL for the vast majority of flights.
All very simple really.
What is more dangerous in the current low pressure environment is to be aware of your True Altitude.
hazek wrote:
Guys, this is really basic, do you really not understand how your aircraft’s vertical position is established correctly? Do you know that not knowing this can get you killed? I mean forget about rules and infringing a CAS, you could literally die if you don’t understand and apply what is listed here:I mean c’mon. Do better. You owe it yourselves.
Either troll or arrogant ignorant. Most people here understand perfectly well what TA and TL are. You seem to not understand that this has nothing to do with the vertical limit definitions of airspace. The Transition Level is the lowest Flight Level available FOR USE by aircraft. This doesn’t mean lower Flight Levels don’t EXIST. Of course they EXIST. They just can’t be used by aircraft in flight but they sure as hell can and do define the limits of airspace.
Airborne_Again wrote:
At some point the rules for altimeter settings were changed so that if you are cleared for a climb (descent) through the transition layer and don’t expect it to be interrupted, you can set 1013 (QNH) immediately.
Had this discussion not long ago with a Spanish airline captain and TRI/TRE. Apparently Spain hasn’t caught up to this. In Spain you’re still required to set QNE during climb when crossing the TA exactly, and the QNH during descent when crossing the TL exactly. Very stupid but I had to do it this way during my sim sessions.
Then in real life I set the QNH as soon as they give me the first altitude instruction. And QNE as soon as they give me the first flight level instruction (and keep the QNH on the standby altimeter for reference).
hazek wrote:
I also noticed you as private pilots on private flights are actually mandated to contact FIS to obtain clearances from Radar which was surprising to me
It’s also not true for VFR at least. I’ve never contacted FIS to get a radar clearance, I’ve always directly called the owner of the airspace and so far never been refused a clearance. (There are some funny exceptions like Edinburgh where they want you to phone them ahead of time, but these are exceptions and AIUI due to the really awful UI of their software).
