Standby
I just want to understand the logic underlying ATC giving me and requiring me to readback QNH immediately after I've reported receipt of ATIS containing that QNH. Remember: The OP is an appeal for us not to readback to ATC something that does not need to be readback. I'm interested to understand why ATC feels it necessary to tell me the QNH at YSCB - necessitating a readback - when I've already told them in my inbound report that I have the ATIS.
I don't get upset either.
I just want to understand the logic underlying ATC giving me and requiring me to readback QNH immediately after I've reported receipt of ATIS containing that QNH. Remember: The OP is an appeal for us not to readback to ATC something that does not need to be readback. I'm interested to understand why ATC feels it necessary to tell me the QNH at YSCB - necessitating a readback - when I've already told them in my inbound report that I have the ATIS.
I just want to understand the logic underlying ATC giving me and requiring me to readback QNH immediately after I've reported receipt of ATIS containing that QNH. Remember: The OP is an appeal for us not to readback to ATC something that does not need to be readback. I'm interested to understand why ATC feels it necessary to tell me the QNH at YSCB - necessitating a readback - when I've already told them in my inbound report that I have the ATIS.
80% of ATC radio time is devoted to protecting ourselves should the pilot err. Why do you think we have to tell aircraft without a clearance to ‘remain outside class (cde) airspace and standby’
If I inadvertently punched in 1035, wouldn't there be a 300' delta between the altitude I've reported and the QNH adjusted output of my transponder on the ATC screen? Alarms going off?
And if the justification is, in effect, "just to cover our arse", don't be surprised or criticise when pilots readback everything, just to get arse-covering confirmation that they've copied everything you've said..
And if the justification is, in effect, "just to cover our arse", don't be surprised or criticise when pilots readback everything, just to get arse-covering confirmation that they've copied everything you've said..
True. But neither of those circumstances exists in the scenario I’m talking about.
But WhisprSYD’s explanation makes the best sense, given the symbiotic relationship between ATC and pilots in which the game of pass the responsibility parcel continues. (Cue the ‘Mayday Fuel’ debate…)
But WhisprSYD’s explanation makes the best sense, given the symbiotic relationship between ATC and pilots in which the game of pass the responsibility parcel continues. (Cue the ‘Mayday Fuel’ debate…)
Then ATC should recite and require read back of the entirety of the current ATIS information, so nothing “gets missed”.
Sheesh.
Angels dancing on the head of a pin...
If they say standby they don't want me to respond and to wait until they can get back to me.
If they give me a QNH even though I have ATIS, I read it back. (Yeah OK it may unecessarily wear out 2 seconds of the lifetime of the PTT while I say the QNH but they are expecting me to do it and everyone else on frequency knows I will be reading it back so bad luck, they have to accept the 2 seconds longer in my clearance readback).
My 2 questions for ATC folk - if you give me something like "report at X" as part of a clearance, I either don't read that back or sometimes respond "wilco" as I don't think that is actually part of a clearance and (probably due ignorance) cannot find anything about a response in the docs. Do you want me to read anything back about a "report at X" or "report passing X thousand" etc?
And my question to anyone - this one a bit embarrassing - many years ago I recall there seemed there was a habit in more casual conversations on the radio to not say "Roger" but instead "Roger D" (perhaps from the phrase Roger Dodger?). Does anyone remember that? Problem is despite telling myself not to do it, something has hardwired that into my brain and I often catch myself adding the "D" to anytime I say "roger"
Am I Robinson Crusoe? Is that phrase a figment of my imagination and never happened?
Angels dancing on the head of a pin...
If they say standby they don't want me to respond and to wait until they can get back to me.
If they give me a QNH even though I have ATIS, I read it back. (Yeah OK it may unecessarily wear out 2 seconds of the lifetime of the PTT while I say the QNH but they are expecting me to do it and everyone else on frequency knows I will be reading it back so bad luck, they have to accept the 2 seconds longer in my clearance readback).
My 2 questions for ATC folk - if you give me something like "report at X" as part of a clearance, I either don't read that back or sometimes respond "wilco" as I don't think that is actually part of a clearance and (probably due ignorance) cannot find anything about a response in the docs. Do you want me to read anything back about a "report at X" or "report passing X thousand" etc?
And my question to anyone - this one a bit embarrassing - many years ago I recall there seemed there was a habit in more casual conversations on the radio to not say "Roger" but instead "Roger D" (perhaps from the phrase Roger Dodger?). Does anyone remember that? Problem is despite telling myself not to do it, something has hardwired that into my brain and I often catch myself adding the "D" to anytime I say "roger"
Am I Robinson Crusoe? Is that phrase a figment of my imagination and never happened?My 2 questions for ATC folk - if you give me something like "report at X" as part of a clearance, I either don't read that back or sometimes respond "wilco" as I don't think that is actually part of a clearance and (probably due ignorance) cannot find anything about a response in the docs. Do you want me to read anything back about a "report at X" or "report passing X thousand" etc?
‘Roger D’ isn’t something I’ve heard in a long time!
Read back a clearance to Darwin ATC - and committed the heinous crime of omitting the read back “CLIMB VIA”.
My other non Aussie crew members groaned and asked me if she was for real? I had to embarrassingly say ‘Yes, they are rather anal here.”
My other non Aussie crew members groaned and asked me if she was for real? I had to embarrassingly say ‘Yes, they are rather anal here.”
But you can't have it both ways. I listen to the loose ATC in the US and think there's an accident waiting to happen.
If you missed a constraint on climb and didn't read back the CLIMB VIA the DN controller would be in trouble. That said, if there's no constraint...
?Your crew would have had kittens inbound when you didn't report POB on first contact....
But you can't have it both ways. I listen to the loose ATC in the US and think there's an accident waiting to happen.
If you missed a constraint on climb and didn't read back the CLIMB VIA the DN controller would be in trouble. That said, if there's no constraint...
But you can't have it both ways. I listen to the loose ATC in the US and think there's an accident waiting to happen.
If you missed a constraint on climb and didn't read back the CLIMB VIA the DN controller would be in trouble. That said, if there's no constraint...
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Here is the answer for YSCB QNH. Calling CB APP will the the first time you get an altitude. Here is the MATS reference. Going into ML or SY, centre will give you the QNH when assigned an altitude, CB giving the you QNH is the same thing.
I know what the rule book says. The question is why the rule books say that.
I’ll try this way: Why doesn’t 9.2.3.1 have at the end: “…unless the aircraft has reported receipt of ATIS information that includes the local QNH.”?
And BTW: Departures for YSCB doesn’t pass local QNH and expect a read back from departing aircraft…
I’ll try this way: Why doesn’t 9.2.3.1 have at the end: “…unless the aircraft has reported receipt of ATIS information that includes the local QNH.”?
And BTW: Departures for YSCB doesn’t pass local QNH and expect a read back from departing aircraft…
LB you really do have your lawyer hat on a bit too tight sometimes. Have a reread of part g of the readback requirements. Then answer this question. Of all the information provided on the ATIS, which item is most likely to get you killed if you get it wrong? I'm not sure how you record your ATIS but if you write it down while bumping around in turbulence and distracted by other things then an incorrect QNH can be recorded. ATC are doing you a favour by confirming what QNH you have recorded regardless of the ATIS identifier. I would suggest that you don't fly in NZ because the readback of QNH requirements would make your head explode.
So Altimetry is important to aviation safety, LL? I’ll have to write that down.
You really do have your ‘try to embarrass LB at every opportunity’ hat on too tight sometimes.
The safety issue is not actually about whether I’ve recorded the correct QNH. It’s actually about whether I’m at the correct altitude. And to be at the correct altitude, it’s usually necessary to have the correct QNH set on the altimeter. That’s how I usually ‘record’ QNH: by setting the QNH on the altimeter to the QNH reported in the ATIS.
There’s a way in which YSCB Approach checks whether I’ve set the correct QNH: There’s a thing called a ‘transponder’. If I report inbound at 5,500’ with information Charlie but haven’t set the Charlie QNH, my transponder will say so, whether or not Approach and I have had a little chat about QNH. It even works when ATC mistakenly gives the wrong QNH! (See incident linked earlier in this thread.)
That’s presumably why the ‘passing (e.g.) 3,400’ on first contact with YSCB Departures is enough. We don’t have a chat about QNH.
Remember what this thread’s about: Unnecessary talk.
You really do have your ‘try to embarrass LB at every opportunity’ hat on too tight sometimes.
The safety issue is not actually about whether I’ve recorded the correct QNH. It’s actually about whether I’m at the correct altitude. And to be at the correct altitude, it’s usually necessary to have the correct QNH set on the altimeter. That’s how I usually ‘record’ QNH: by setting the QNH on the altimeter to the QNH reported in the ATIS.
There’s a way in which YSCB Approach checks whether I’ve set the correct QNH: There’s a thing called a ‘transponder’. If I report inbound at 5,500’ with information Charlie but haven’t set the Charlie QNH, my transponder will say so, whether or not Approach and I have had a little chat about QNH. It even works when ATC mistakenly gives the wrong QNH! (See incident linked earlier in this thread.)
That’s presumably why the ‘passing (e.g.) 3,400’ on first contact with YSCB Departures is enough. We don’t have a chat about QNH.
Remember what this thread’s about: Unnecessary talk.
QNH has far more importance for IFR aircraft into major ports for instrument approach reasons, en-route whether you are plus/minus 5 hpa is not going to have much affect on safety at all. At the bottom of a Cat 1 approach with other errors combined 5 hpa could mean reaching terra firma a lil prematurely. Add that an IFR aircraft may not fly level from transition altitude to touch down allowing any altimetry error catches by ATS. Easier just for ATS to pass and confirm QNH for all aircraft and not be selective I suppose is what they are aiming for.
Transponder Mode C
Mode C altitude transmissions are independent of the barometric altimeter sub-scale setting. The transponder can get its information from one of two sources: an encoding altimeter, which transmits a pressure altitude reading to the transponder or (more commonly) a blind encoder permanently set to 29.92 (pressure altitude). In either case, the altimeter setting does not affect the information sent which is always based on 29.92. ATC’s computers apply the current altimeter setting converting it to altitude (which will only match your indicated altitude if you have set the correct QNH).
FlySafe
PJ88
FlySafe
PJ88