Captain-random wrote:
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 ?
The only decent thing to do is to request descent from ATC, assuming you are flying in controlled airspace. In a radar environment you fly at what ever altitude you agree upon with ATC within the constraints of MORA, MSA, MRA etc.
WRT to lost comms:
A controlled flight experiencing communication failure in IMC, or where it does not appear feasible to continue in VMC shall:
1. set transponder to code 7600;
2. maintain for a period of 7 minutes the last assigned speed and level or the minimum flight altitude, if the minimum flight altitude is higher than the assigned level. The period of 7 minutes commences:
a. if operating on a route without compulsory reporting points or if instructions have been received to omit position reports:
– at the time the last assigned level or minimum flight altitude is reached; or
– at the time the transponder is set to Code 7600, whichever is later; or
b. if operating on a route with compulsory reporting points and no instruction to omit position report has been received:
– at the time the last assigned level or minimum flight altitude is reached; or
– at the previously reported pilot estimate for the compulsory reporting point; or
– at the time of a failed position report over a compulsory reporting point, whichever is later.
NOTE: The period of 7 minutes is to allow the necessary air traffic control and coordination measures.
3. thereafter, adjust level and speed in accordance with the filed flight plan;
NOTE: With regard to changes to level and speed, the filed flight plan, which is the flight plan as filed with an ATS unit by the pilot or a designated representative without any subsequent changes, will be used
I think ATC are only human and make “unofficial” decisions partly based on whether the pilot looks like he knows what he is doing. If you are flying near the base of CAS, say FL070, you look like an amateur. If you are flying at FL150, you look like you know what you are doing. Even more so if you are flying at FL200 (light GA I mean).
How well you do the radio also matters, in many cases…
This is one reason I never fly long-enroute below FL100, even if technically one could, and still get a service in CAS. One also gets a much better view of the wx ahead, which you tend to not get at a few k feet.
Cobalt wrote:
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.
Sometimes they get you down far too early too. If i’m IFR I wouldgenerally be flying a pressurised aircraft; Inbound to Toussus is often a long drag at low level, and London always want you far too low – FL260 40 before Biggin when going to the Doncaster or East Midlands area.
Basically ATC can’t please anyone!! 
Peter wrote:
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
My understanding is that is the procedure in IMC. in VMC I think you’re supposed to land at nearest suitable aerodrome (I’m less certain if reasonable to start a descent from a busy airway though)
In VMC:
Continue to fly in visual meteorological conditions;
Land at the nearest suitable aerodrome; and
Report the arrival by the most expeditious means to the appropriate air traffic control unit
In IMC or when conditions are such that it does not appear likely that the pilot will complete the flight in accordance with the prescribed VMC RCF procedures above :
The Legacy switched its transponder off by mistake. The report lists 8 things, any of which would have avoided the collision if it hadn’t occurred.
I imagine the closing speed was equivalent to one mile per 4 or 5 seconds. That doesn’t leave much opportunity for see and avoid.
Did neither aircraft have TCAS? Also I wonder if they were IMC at FL370, so perhaps had a chance to see and avoid? ( I haven’t read the report)
I realise airways try to keep aircraft in the same bit of sky but Brazil is a BIG country with not that high traffic density unless you are around the major airports. (Rio, Sau Paulo etc)
You also end up with large areas where you don’t get ATC radio coverage.
Jepp charts and flight plans are used for initial routing and following a route after a comm failure. Otherwise follow ATC.
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) 
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.
Thanks for the responses. :)
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.
