Descending once cleared for approach
 

My first post, here goes. On a recent Europe trip, we were descending to FL 80, proceeding as directed to an iaf at a French airport. Then we were cleared for the ils approach. Is it ICAO procedures that further descent levels or altitudes are up to the pilot (for eg, 25 mile MSA)? Is there any online documentation that details this, similiar to the US AIM?

The details were LFOK, Vatry Chalons, France, Ils Z RWY 10, iaf was KELON

Spud3

Yep that is how it works. Don't have a reference to hand at the mo. Once ATC have cleared you to the IAF then making any intermediate step/check altitudes, config changes, speeds and terrain avoidance are all down to you. A good example would be the ILS onto R13 at LEMG. ATC will clear you to either a FL or altitude and clear you for the approach. There is significant terrain on the approach and hence a stepped descent until the latter stages where you pick up the glide. We would arm the localiser and lock onto that about 25nm out or so and then step descend to the final platform altitude before arming the glideslope to ensure terrain clearance.

Yup, it sounds like from what you said that altitude would be at your discretion. If you were cleared for the Arrival into the airport you could follow the flight path for the arrival but you can't descend to the chart altitudes until ATC either clears you down to them or clears you for the Approach. So if you were on an Arrival and then got cleared for the Approach, you could descend down to the minimum altitudes on the Arrival chart, as well as the other minimums you mentioned such as MSA as you come to them.

MSA is not relevant IF you are ON a published approach path and you observe the published minimum altitudes. MSA represents clearance on the highest obstacle in the sector and will be higher than published approach restrictions. However, fly OFF that published approach eg take a short-cut........................

In my situation there was no arrival. Originally we were enroute, I think direct the airport or the vor on the field. Then atc gave us direct the iaf.

Potkettle, I looked up your example, however it is for proceeding FROM the iaf. Mine is TO the iaf, where there were no "intermediate step/check" altitudes that you described. So....I see no option for me except the 25 mile MSA, which is not centred on the IAF.

Italia, I was not on an arrival, and atc did not give me any descent, just cleared for the approach, while I was at FL 80. So am I correct to wait until within the 25 mile MSA and then leave FL 80?

BOAC, what is really interesting is that the MSA within 18 miles is 2100 feet, while the altitude past the iaf at 11 dme while inbound to the field is still 2500 feet. Any idea why?

If you are cleared direct to the IAF and cleared for the approach, YOU MUST MAINTAIN LAST ASSIGNED ALTITUDE UNTIL YOU REACH THE IAF!!! Since you are not on any published procedure, you must adhere to your ATC clearance.

Where does it say ANYWHERE that while on a vector you can descend at your discretion without further clearance?!? I've never heard of that one!

Intruder, I wasn't on a vector, and "maintain last assigned altitude" til on a portion of the instrument procedure **I think** might be a USA only requirement. Not sure.

Where does it say I can descend to MSA once cleared for approach? Don't know, that's why I was asking those who know French/ICAO procedures

And a reference to an online AIM type ICAO document.

Surely common-sense applies here anyway? If in doubt ask ATC. Tell them what you are doing as well - this helps other traffic.

Spud - I guess 2100 was unnecessarily low at 11D? 2500 about right for 2.5 slope?

Mig3, we were in descent to FL 80 and told to proceed direct to an iaf, and we were not on an arrival. Immediately after that we were cleared for an approach well before reaching the iaf. In Australia then, is MSA included as one of those altitudes you are now cleared to descend to once withing the specified distance?

Its real simple, if cleared the apch, you do just that, ensuring when doing so you dont bump into anything solid. Last week when sixty miles back from destination it went like this"CG XXX, cleared out of controlled airspace for the apch into CYXXX," now there are some big lumps of rock around this particular place, the controller presumes you have charts giving the MEA and wont try to move one with the pointy end of your aircraft. Lets not complicate things.leave that to the nerds on the groundspeed thread!

As a French ATCO I'd say you take up the IAC chart and look at the altitude restrictions following the IAF. Since there only is the G/S capture at 2500ft, you can descend until 2500ft at convenience according to the rules for direct arrivals (and not STARs), which means you do not get below the MSA, inside the 25NM sectors centred on CAV. And if you're further than 25D from CAV, then it's FL80 minimum.

If there had been a level restriction at KELON on the chart then you would have had to stop descent at that level (or adjust descent rate to be above it at KELON...).

Radar vectors are what they are, that is to say headings to follow. If on a direct to a fix, it's no longer considered vectors. Since you're not on a specified route, the ATC will clear you at or above the minimum safe radar altitude of the sector, which usually is lower than en-route charts.

But in doubt, ask over R/T...

You were cleared to a fix, descend to 8000. Do that.

You were then cleared for the approach. The fix to which you are currently cleared happens to be the IAF. Your clearance before the approach has not changed. Proceed direct to that fix, descending to 8000. Descend from 8000 only after established on the approach (i.e., passing the IAF) or specifically cleared for lower by ATC.

I have not seen any rules written anywhere that are different from the FAA rules. What have you seen WRITTEN that gives you the impression you can descend below 8000 enroute to the IAF when only cleared to 8000?

I don't have the charts right now so I can't say for sure but if you are cleared for the approach you do not need further clearance to descend. You do still need to follow the minimum altitudes that are on the approach chart and the other IFR charts. If you're already at the lowest altitude for your position then you can't descend.

Cleared for arrival = cleared for the path dictated on chart, do not descend without clearance

Cleared for approach = descent at your discretion while adhering to the altitude restrictions on your "path" and cleared to fly the arrival "path".

Once again, do not confuse clearance to descend ON THE APPROACH -- either after passing the IAF or after intercepting the approach course inside the IAF -- with descent PRIOR TO the approach. There is no inherent "clearance" to descend any further than the explicit ATC cleared altitude when being vectored to the approach course or when cleared direct to the IAF or a fix inside the IAF.

Descent on a STAR or other published arrival route is different, and a clearance may be given to "descend via" the arrival, including altitudes. Clearance procedures and phraseology differs among US, UK, and the rest of the world, though, so make sure you know what your clearance means.

MSA is for emergency and lost communications reference ONLY.

I don't understand the confusion here. If ATC clear you direct to the IAF and whilst routing there you are cleared for the approach you may descend in accordance with the approach once established on it. However, you are not on the approach until you reach that IAF. Any descent below that FL80 needs a specific ATC clearance. If FL80 is too high to intercept then you need to request lower. The only other way around it (assuming weather permits) is to request a visual approach. Surely it is no different to being cleared for the ILS whilst on an intercept heading and realising that your last cleared alt will be too high to intc the GS. I know plenty will just wind the MCP alt down a coupe of hundred feet to make it work but I think everyone would agree that is not strictly correct.

In the circumstances you have described assuming you needed a lower FL/alt to make the approach work surely you ask for descent or at least clarification of the clearance, and not simply descend the MSA without talking to anyone about it first?

Spud3 asked a straightforward question about procedures while undertaking an arrival into a French airport.

There are two relevant sets of procedures here. The definitive ones are French. JeeHell has answered, self-identifying as a French ATCO. If what he says requires confirmation, I can ask another colleague to contribute who is a French ATCO and also on PPRuNe.

The second set of procedures would be those agreed through ICAO. It is interesting, as always, to find out where these might differ from local (here, French) rules. I don't know. Anyone?

Third, it is not clear to me that Intruder yet comprehends that not all procedures everywhere are the same. Not even in adjacent countries in Europe.

PBL

ENR GEN 1.7 : Differences betweew ICAO and French Regulations
Good luck browsing that file :E


LFOK Chart
Looking at the chart, 2 interesting things:

1. If you overfly KELON at FL80, then you're up (or down as you wish :rolleyes:) for some turns before you reach the compulsory 2500ft at the IF. Or you have good S/B... So what is the point in clearing for approach as early prior to KELON as Spud3 describes?
2. Entry protection of hold at KELON is 5000ft pressure altitude. So if you start holding at FL80 you may end up in an other airspace, so I'm pretty sure standard local instructions are to clear at least down to 5000ft if holds are expected.

I'd say the ATCO might have been a bit lazy, from what I can picture from the situation, I would have cleared the ACFT down to 5000ft in the same message as the approach clearance, in order to clear any ambiguities...(here 2500 would have even been ok, I think the minimum radar altitudes in the area are lower than that even 25NM away from CAV)

Not in the U.S.....There was a TWA accident at Dulles (IAD) several years ago....

Fly safe,

PantLoad

It always amazes me that in all the reams of ICAO documents, including standard phraseology for clearances, there appears to be nothing that tells pilots what the words actually mean. There is no equivalent of Section 5-5 of the FAA AIM.

In the UK it is generally believed by ATC that a clearance for an approach permits the aircraft to descend immediately to the charted altitude at the IAF. This is the excuse normally given for the UK anomalous phraseology for ILS approaches.

Thanks for the replies. As the OP, please let me reinterate that the ONLY question I had was on whether it is permissable in France to descent to the 25 mile MSA altitude when off airways/route but cleared direct to an iaf and cleared for approach.

Those who referenced "intermediate/check altitudes", "stepped descents", "platform altitudes", chart altiitudes", "minimum altitudes", "common sense", "mea", "altitude restrictions" unfortunately for me did not give me a clear answer.

My thanks for Intruder for at least coming forward and giving his answer, a definite NO.

Jeehell seems to say YES I can use the MSA once cleared approach.
Ast83 seems to say no.
PBL, yes, please ask your colleague for his input.
PantLoad, the TWA aircraft was well below any safe altitude. No one is suggesting that.