OnCourse Software

Hi Dave, I am watching some videos in order to evaluate PF3 before purchasing. I have just started, but what I already don't like is to hear on the departure frequency, after takeoff, the controller saying both to me and to each AI aircraft always the same "radar contact, QNH...". This is deeply unrealistic, I have been listening to radio communications for years and in fact there are different instructions that can be given, but never a "QNH...". Most times a clearance to a higher altitude with respect to the initial one, or a "direct to" clearance. I understand that PF3 doesn't know which altitude and where the AI airplanes have been cleared to by the default ATC, but couldn't a workaround be found? Thanks.

jgoggi wrote:

Hi Dave, I am watching some videos in order to evaluate PF3 before purchasing. I have just started, but what I already don't like is to hear on the departure frequency, after takeoff, the controller saying both to me and to each AI aircraft always the same "radar contact, QNH...". This is deeply unrealistic, I have been listening to radio communications for years and in fact there are different instructions that can be given, but never a "QNH...". Most times a clearance to a higher altitude with respect to the initial one, or a "direct to" clearance. I understand that PF3 doesn't know which altitude and where the AI airplanes have been cleared to by the default ATC, but couldn't a workaround be found? Thanks.

It really depends on where you are listening to the ATC. As you say there are a host of different instructions but for obvious reasons an ATC programme has to limit those choices. QNH is always given where the aircraft is flying in or to airspace that is below the transition level. And for flying into an airfield either that airfield QNH is is given or the QFE.
"Radar Contact" is rarely said in ICAO and in fact PF3 has much reduced the frequency of that. If an a/c is making contact with an Approach controller he too will give the QNH simply because it is always changing and may be different to the area QNH that may have been previously given. So to say "This is deeply unrealistic" is unrealistic!

Another point to remember is isobars. They are as you may already know points of equal pressure. When an aircraft flies across those isobars the pressure changes. Isobars can be quite close together. The closer together the stronger the wind and the greater the pressure difference between them. Even when flying from LIMZ to LIMF which is less than 40nm as the crow flies there is almost always a pressure difference of 1Mb sometimes as much as 3Mb (or 20Mb if there is a storm in the area!). So in this case i.e. flying into LIMF it is quite normal and quite correct for one controller to give the area QNH and another say Approach or Tower to repeat it or give another. It is not as you say "deeply unrealistic". In fact it is mandatory!

If you are departing and the controller asks to climb to a higher altitude (i.e. height above sea level) firstly that means that it is below the transition level and therefore the area QNH must be given as part of the instruction. Because it can and does change between the time you look at the charts in the Ops room, Clearance Delivery and the take-off. If you are cleared to a Flight Level then that is above the transition level and the standard ISA pressure of 1013.2Mb applies. So no QNH is given.
Please make sure that when watching vidoes that they are of PF3 and not of PFE. The reason being that a lot has been changed between the two programmes. Including the phrase "Radar Contact" which has largely been dropped as it only applies in certain circumstances.

In few words, an example of what usually happens in real life (sorry if I use an Italian example...):
Pilot - "Departure, Alitalia 610 is with you, climbing to 6000 on GILIO 5A"
ATC - "Alitalia 610 good morning, no speed restriction, climb to FL 120"
or
"Alitalia 610 good morning, proceed direct to GILIO"
or something else, but I have NEVER heard (hearing controller instructions for 25 years...) the controller say only "Alitalia 610 QNH 1011", because the pilot knows the QNH from the ground and does not need to be reminded and at departure the airplane quickly passes the transition altitude (usually 6000 or 5000 ft in Europe), so the QNH is not an essential information and is quickly replaced by STD (it's instead essential during approach, when the airplane comes from STD and needs to know the local QNH). Further, in all PF3 videos I have seen the controller says the same "QNH..." and nothing else to ALL the airplanes contacting departure... Highly unrealistic...

I'm not as familiar with the real world procedures as you two are, but from my limited experience with live ATC I know that the regulations are sometimes applied differently at different airports. Can you cite for me (or Dave) what the official documents for Italy and/or ICAO say in this regard?

Also, if we are talking about the user aircraft, you have already been given your initial altitude as part of your clearance, so an altitude instruction immediately off the runway is not necessary (until you are close to your initial clearance altitude). In terms of heading, if you are not flying a SID, your takeoff clearance includes either an instruction to fly runway heading or an initial heading to assume once airborne, with further vectors to follow. If you are flying a SID, no heading instruction is appropriate, as you have already been cleared to fly your procedure.

ThomasAH wrote:

I'm not as familiar with the real world procedures as you two are, but from my limited experience with live ATC I know that the regulations are sometimes applied differently at different airports. Can you cite for me (or Dave) what the official documents for Italy and/or ICAO say in this regard?

Thomas, Italy is ICAO so the same regulations apply. The first time one is passed to a controller having previously been given an instruction to fly to an "altitude", that sector controller need not give the QNH unless it has been changed. Because that previous instruction would have contained the QNH. If said sector controller issues another instruction to climb/descend to an "altitude" then he need not give the QNH again unless it has changed. Every time you contact a new controller below the transition level he/she should give the area QNH.