Pretty much spot on for Biggin arrivals, London Control gets you to Detling at 4,000, and hands off “leave Detling on heading xxx, contact Thames Radar…”. It is vectors from there,
If they vector you to a long final intercept, the step down clearances (instead of being cleared to 1,800 immediately) surely help keeping yo in controlled airspace – my point was more that intercepting the glide path at 3,000 ft does pretty much the same thing, but they have to descend you to the “platform altitude” so you start your descent at the FAF. So you end up with a slightly higher workload. you can of course use a slow descent rate to follow the glide path unofficially anyway, they should clear you lower early enough – if they don’t they ballsed it up anyway as you will be above the GP.
From here
Peter wrote:
Interestingly I got cleared for the ILS at 3000ft so descended to 2000ft on my own
The same happened to me last weekend with a very competent-sounding ATC, me approaching EDFM. I was cleared for the approach already around 8 minutes prior to arriving at KETEG (IAF), still at 6000 feet, where the approach starts out of KETEG at 5000 feet. Obviously there was no traffic whatsoever, so he just wanted to “get rid of me” (not meant in a derogatory way, just to simplify work for all involved). However I was puzzling the same, whether I may descend at some point, maybe before KETEG, or not. How may an approach clearance be understood if you are off-route and still too high for the approach?
So I requested a descent two minutes before KETEG and got a descent clearance together with a second full approach clearance.
UdoR wrote:
How may an approach clearance be understood if you are off-route and still too high for the approach?
It means you can descent at will to the altitude appropriate for starting the approach. A descent clearance is implied.
There is a corresponding obligation on ATC to not issue an approach clearance until it is obstacle safe.
But that’s not the issue in this case.
Airborne_Again wrote:
UdoR wrote: How may an approach clearance be understood if you are off-route and still too high for the approach?It means you can descent at will to the altitude appropriate for starting the approach. A descent clearance is implied.
I believe this is incorrect and could be fatal.
Having been ‘cleared aproach’ you can descent only when established on published part of this aproach. If you are not there yet, i.e. ‘off-route and still too high’, your aproach clearance doesn’t imply any descent. If you need to descent you need to request it.
Also, when on published arrival route, it presents only a horizontal guidance and even with published altitudes you can’t descent on it without clearance.
Destinatus wrote:
I believe this is incorrect and could be fatal.Having been ‘cleared aproach’ you can descent only when established on published part of this aproach. If you are not there yet, i.e. ‘off-route and still too high’, your aproach clearance doesn’t imply any descent. If you need to descent you need to request it.
Good to read that I’m not the only one who’s not so sure about this. Because the IAP was 5000 or above. So it would’ve been absolutely comprehensible, if ATC would have wanted me to arrive at say 6000 overhead the IAP.
So if ATC gives a clearance for approach for an off-route aircraft, who is responsible for ground clearance? And is this an implicit descend clearance (e.g. regarding traffic..)?
Destinatus wrote:
Having been ‘cleared aproach’ you can descent only when established on published part of this aproach. If you are not there yet, i.e. ‘off-route and still too high’, your aproach clearance doesn’t imply any descent. If you need to descent you need to request it.
UdoR wrote:
So if ATC gives a clearance for approach for an off-route aircraft, who is responsible for ground clearance? And is this an implicit descend clearance (e.g. regarding traffic..)?
If an aircraft is not on a published route and also not on a direct specified in the flight plan, then ATC is responsible for terrain clearance – that’s explicit in PANS-ATM. In that case I would take an approach clearance to imply that you can descend to the altitude where the approach starts. Of course, I would cross-check with the MSA/TAA.
Unfortunately, PANS-ATM doesn’t say anything specific about how an approach clearance allows you to descend.
Airborne_Again wrote:
If an aircraft is not on a published route and also not on a direct specified in the flight plan, then ATC is responsible for terrain clearance – that’s explicit in PANS-ATM.
Correct, if ATC gives you heading or point to fly to the terrain clearance is their responsibility.
Airborne_Again wrote:
In that case I would take an approach clearance to imply that you can descend to the altitude where the approach starts.
Well, there could be terrain or traffic between your position and the point or leg of the approach you are cleared for. The terrain clearance and traffic deconfliction is the ATC responsibility as far as you don’t descent ‘at will’ but only as cleared.
Airborne_Again wrote:
If an aircraft is not on a published route and also not on a direct specified in the flight plan, then ATC is responsible for terrain clearance – that’s explicit in PANS-ATM. In that case I would take an approach clearance to imply that you can descend to the altitude where the approach starts. Of course, I would cross-check with the MSA/TAA.
In the US, it is clear. An approach clearance authorizes descent, but only when established on a segment of the procedure. If on a random course to an approach fix, pilots must remain on the last assigned altitude until established on a segment of the approach. TWA 514 crash into mountains on an approach into Dulles airport changed everything in the US. In the US, the MSA is not treated as an operational altitude and pilots are not authorized to descend to the MSA based on an approach clearance. A TAA segment is treated as part of the approach and an approach clearance permits descent to the TAA segment charted altitude. In effect a TAA is an RNAV feeder route (transition route) to the IAF.
An approach clearance authorizes descent, but only when established on a segment of the procedure. If on a random course to an approach fix, pilots must remain on the last assigned altitude until established on a segment of the approach
Interesting. I’ve never heard that in the European context – or indeed in the US context when doing my FAA IR at KCHD in 2006. TWA 514 crash was in 1974.
The obvious Q is whether ATC is specifically restricted from issuing the approach clearance too early.
segment of the approach
Is that after an IAF? Or would it include say a holding pattern which preceeds an IAF?
