Hopefully not such a silly question…
If I’m flying on an IFR flight plan which includes a decent from FL100 – FL080 at a certain waypoint… who’s responsibility is it to initiate the decent ? Me because ATC should expect me to do it as filed or ATC ?
Thanks
Assuming you are in controlled airspace (E or above for IFR):
You always remain at your CLEARED altitude until ATC clears you to a different one. The only exception is loss of communications.
If the descent is in the flight plan because you needed it to get around some silly CFMU rule – just carry on.
If the descent is in the flight plan because you want it – request if from ATC when you reach it, or if you really MUST descend at that point then request it ahead of time. “xxxx, request descent flight level 80 at WPT”.
On a different note – you are also responsible to ask for your descent from cruise altitude for the approach. While ATC will initiate this at some point, they may do this quite a bit later than you want to, especially if you are high, since they are used to pressurised aircraft which typically fly steeper descents than your ears might like.
Most level changes generated by automatic routing tools are spurious. They are inserted to get around Eurocontrol algorithm quirks and you don’t actually fly them. You don’t ask to fly them and ATC does not ask you to fly them.
For example in
EDNY N0150F080 ALAGO5E ALAGO Z5 LOKTA DCT UBASI/N0151F090 DCT BADLI/N0152F100 Q762 LULAT Z104 GESLO N852 LNO L607 KOK DCT VABIK DCT DVR M140 WIZAD/N0151F090 M140 MAY EGKA
all the level changes are completely spurious. I flew the whole route at FL100.
One obvious exception is crossing the Alps e.g.
EGKA N0152F110 SFD DCT ROTNO DCT KONAN L607 SUXIM DCT AGBUL DCT OLIVI DCT MND DCT OKIBA DCT ABTAL L173 RIXED DCT ABGAS DCT AMEXO/N0150F120 DCT OSDER DCT ADILO/N0148F130 DCT KTI DCT NIGEB LIPB
where the F130 is actually needed 
And the other obvious thing is that you need to descend at some point, to land…
The answer for the genuine cases is that it is a bit of each. Sometimes ATC remind you with “Nxxxx ready for descent?” but sometimes they forget and you have to call them with “Nxxxx ready for descent”. Or to cross the Alps you might call them with “Nxxxx request climb flight level 150”. In general, if over water, you want to stay high as long as possible, while in more general flying it is best to do a continuous descent so if at say FL150 I would start descending say 100nm before the destination, and that would be slightly over 300fpm all the way down which is nice and comfortable and fuel efficient. ATC will not authorise a continuous descent (to light GA) but they will give you steps and you manage the continuous descent within those.
The assumption is that you can achieve 500fpm up or down but ATC know that light GA usually can’t climb that fast at altitude, or may not want to descend that fast. Usually there is no other traffic in the airspace where we fly so they are relaxed.
Note also that due to defective software used by NATS, UK ATC see only the first level in a flight plan so in the 2nd one above they see only the F110 and they will give you that as your cruise level, unless you ask for different.
ATC does it for you. But they can be late, or have some other reason to keep you high longer than you’d like.
An example here on the west coast is when you’re going into Napa Valley. Then they keep you at 16000ft above the approaches into San Francisco and then slam dunk you in. Last time I did it, I basically had to pull throttles back to idle and get the gear down to be able to make rwy.
If you feel you should be descending at a certain point, never hurts to ask if you can start descent. Unless they have traffic below you or some other reason, they’ll most likely give it to you.
Captain-random wrote:
Hopefully not such a silly question…
The original Q:
“who’s responsibility is it to initiate the decent ? "
is a perfectly good one; I am having difficulty grasping the relationship to the Brazil mid-air which had multiple causes and was mostly due to sloppy ATC and with no radar coverage. The issues exist all over Africa which is why, reportedly, European airlines flying there set up their track to be a few nm to the right of the route.
European IR training still uses 20+ year old Jepp airway charts and doesn’t cover the practicalities of how IFR ATC works.
Thanks for the responses. :)
Peter wrote:
I am having difficulty grasping the relationship to the Brazil mid-air which had multiple causes and was mostly due to sloppy ATC and with no radar coverage.
The report suggests that the full clearance should have been (to reflect the FPL)
He believed that the ACC BS controller would need further clearances from the other sectors of Brasilia, and also from Manaus, and said that, for this reason, he did not transmit the full clearance that should have been the following:
“N600XL cleared for Eduardo Gomes, level 370, direct Poços de Caldas. After Poços de Caldas, maintaining level 370 on UW2, up to Brasilia. After Brasilia, level 360, on UZ6, up to TERES position. After TERES, level 380, maintaining UZ6”.
In fact it was
NOVEMBER SIX ZERO ZERO X-RAY LIMA, ATC CLEARENCE TO EDUARDO GOMES, FLIGHT LEVEL THREE SEVEN ZERO DIRECT POÇOS DE CALDAS, SQUAWK TRANSPONDER CODE FOUR FIVE SEVEN FOUR, AFTER TAKE-OFF PERFORM OREN DEPARTURE.
which resulted in a collision at FL370 after N600XL lost comms after Brasilia.
The implication of the report is that the level changes would have been expected to be made spontaneously by the crew without intervention by ATC.
In Europe, almost all clearances come with “flight planned route”. If that is the case, would you expect any level changes in the FPL to be made spontaneously by the crew? I think if you assemble a roomful of N aviation professionals, (pilots, ATCOs and regulators) you’d get at least N+1 different answers to that question.
Of course if you’re in communication with ATC, clearances don’t matter much — you just ask for clarification. Clearances only matter when you lose comms, like the Legacy did. That’s when they need to be perfectly unambiguous.
Which is why, after 30 years of flying IFR in Europe, I think Captain-random’s question, far from being a silly one, exposes a huge hole.
I agree; in an IFR IN CAS (as distinct from IFR OCAS where you don’t have a clearance for anything anyway) lost-comms scenario you are supposed to fly the route exactly as filed, turn up at the FAF at the filed time, and land at the filed ETA
I don’t see any ambiguity there… well except that achieving the filed timing is going to be damn nearly impossible, but on the plus side anybody setting 7600 is going to get visual (or a radar contact) with an F16 or similar pretty fast anyway, which will resolve any ambiguity
The fact that ATC allow me to fly that stepped route at FL100 all the way, without any communication, is a bit like, ahem, most IN CAS flying in France where they say “radar contact” and you just carry on, and it all works (until somebody screws up, forgets some ZIT, and then it doesn’t) 
