Descending once cleared for approach

[spud3]

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

[potkettleblack]

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.

[italia458]

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.

[BOAC]

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........................

[spud3]

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?

[Intruder]

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!

[spud3]

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.

[BOAC]

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?

[spud3]

In OZ at least, if you're cleared the approach, your cleared to descend as required (in accordance with minimum alts etc. if in IMC)


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?

[clunckdriver]

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!

[JeeHell]

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...

[Intruder]

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?

[italia458]

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?

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".

[Intruder]

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.

[ast83]

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?

[PBL]

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

[JeeHell]

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.ENR GEN 1.7 : Differences betweew ICAO and French Regulations (https://www.sia.aviation-civile.gouv.fr/aip/enligne/fr/..%5CPDF_AIPparSSection%5CAIP%20FRANCE%5CGEN%5C1%5C1008_GEN-1.7.pdf)
Good luck browsing that file :E


LFOK Chart (https://www.sia.aviation-civile.gouv.fr/aip/enligne/fr/..%5CPDF_AIPparSSection%5CIAC%5CAD%5C2%5C1008_AD-2.LFOK.pdf)
Looking at the chart, 2 interesting things:
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?
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)

[PantLoad]

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

Fly safe,

PantLoad

[bookworm]

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?

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.

[spud3]

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.

[spud3]

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.

Bookworm, are you suggesting that atc is meaning descent at pilots discretion? If so, are pilots then permitted in the UK to use the MSA in determining their safe altitudea?

[flown-it]

If I were doing this I would put 5000 as a "hard" altitude at KELON and go direct to the fix. Ensure LNAV is the active mode, set the MCP alt to DA and arm VNAV. I would then get a TOD at about 5 miles from the fix (approx 3000 ft to loose from FL80) which would be well within the MSA 25.
I would allow LNAV/VNAV to make the turn to final and since you have DA in the MCP, VNAV will cross the IAF (KELON)at 5000ft but in a descent allowing you to arm the approach and get a LOC and G/P capture.
I don't have the chart so I don't know the distance between the IAF and the FAF. Depending on that, VNAV may well level you at 5000 until you reach the G/S outside the FAF.
And NO you are not capturing the G/S from above you are capturing it further out but from below.

[spud3]

Flown-it. Thanks but I wasn't looking for aircraft flight director handling techniques or equivalent. I was looking for a yes, or a no. And, preferably, an icao reference.

Surely there must be an icao doc similar to the US AIM.

Anyone?

[bookworm]

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

Synopsis. (http://aviation-safety.net/database/record.php?id=19741201-0)

(I was puzzled that I couldn't find this at first, as I also remembered it as IAD -- the database has the destination as DCA, but the synopsis clearly shows the destination was Dulles.)

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.
...
Bookworm, are you suggesting that atc is meaning descent at pilots discretion? If so, are pilots then permitted in the UK to use the MSA in determining their safe altitudea?

The MSA has nothing to do with it. Nor has pilot's discretion. It is absolutely clear (PANS-ATM 8.6.5.2) that ATC is responsible for terrain separation when giving a vector or a direct clearance. The issue is whether the clearance for an approach includes an implicit instruction to descend to the initial altitude for the approach.

FAA AIM 5-5 (http://www.faa.gov/air_traffic/publications/atpubs/aim/Chap5/aim0505.html) deals with the issue explicitly:

Pilot
3. Upon receipt of an approach clearance while on an unpublished route or being radar vectored:
...
(b) Maintains the last assigned altitude until established on a segment of a published route or IAP, at which time published altitudes apply.

Controller.
...
2. Issues an IFR approach clearance only after the aircraft is established on a segment of published route or IAP, or assigns an appropriate altitude for the aircraft to maintain until so established.

AFAIK, ICAO does not offer guidance.

[spud3]

While the FAA deals with it explicity, so do Canadian authorities, although in an opposite way.

Jeppesen Airway Manual, Air Traffic Control, State Rules and Procedures, Canada
clearance for an approach may not include any intermediate
altitude restrictions. The pilot may receive this clearance while the aircraft is still a considerable distance from the airport, in either a radar or non-radar environment. In these cases, the pilot may descend, at his/her convenience, to whichever is the lowest of the following IFR altitudes applicable to the position of the aircraft:
a) minimum en route altitude (MEA);
(b) published transition or feeder route altitude; or
(c) minimum sector altitude (MSA) specified on the appropriate instrument approach chart.
emphasis mine.

[italia458]

While the FAA deals with it explicity, so do Canadian authorities, although in an opposite way.

Jeppesen Airway Manual, Air Traffic Control, State Rules and Procedures, Canada
clearance for an approach may not include any intermediate
altitude restrictions. The pilot may receive this clearance while the aircraft is still a considerable distance from the airport, in either a radar or non-radar environment. In these cases, the pilot may descend, at his/her convenience, to whichever is the lowest of the following IFR altitudes applicable to the position of the aircraft:
a) minimum en route altitude (MEA);
(b) published transition or feeder route altitude; or
(c) minimum sector altitude (MSA) specified on the appropriate instrument approach chart.
emphasis mine.

spud3... that is correct. I know Transport Canada has their AIM posted on the website. I'm guessing that the French aviation authority would have some site and possibly it's regulations posted there as well.

I fly in Canada and can confirm that Jeppesen quote. Intruder is incorrect, I've never heard of the MSA only being used for emergency. You're required to follow all altitudes on your charts appropriate for your flight (including the MSA) unless on radar vectors where you might be taken lower than the lowest published altitude.

[SeniorDispatcher]

>>>(I was puzzled that I couldn't find this at first, as I also remembered it as IAD -- the database has the destination as DCA, but the synopsis clearly shows the destination was Dulles.)

TWA514 was a scheduled CMH-DCA flight that diverted to IAD due to crosswinds at DCA.

ASN Aircraft accident Boeing 727-231 N54328 Upperville, VA (http://aviation-safety.net/database/record.php?id=19741201-0)

(NTSB AAR link at the bottom of the above page...)

[JeeHell]

All French AIP is viewable online on SIA - La référence en information aéronautique (http://www.sia.aviation-civile.gouv.fr/default_uk.htm)
On the left column, look at the items French Regulation (only in french afterwards though) and AIP-Charts (which will give both charts AND the En-route manual which I already quoted in my previous post link. In EN & FR)

[johns7022]

Some years back I left Kalispell, MT at night for this little airport just South of the Arctic Circle.....the first thing that struck me was the lack of radio chatter, hardly any lights down below, then about 200 nms out they said 'Cleared for any approach at 'X' airport'

So I am sitting there...a whopping 2500 hrs of flight time, scratching my head at how I was going to do this...

Needless to say I considered flying to the IAP, at 14000ft, then circling down(lol)..that would be the safe thing do for for sure...then I took a look at the MEAs..got down to one of those..then found the MSA..got down to that..crossed the IAP at the published ALT....then did a full instrument approach.....It's easy if the aiport has a VOR but if you get down to an MEA...flying to an NDB...MSA seems the way to do it..

[Type1106]

I believe there is some confusion here when discussing MEA and MSA.

MEA is defined as 'Minimum en route altitude (MEA) is the lowest published altitude between radio navigation fixes that assures acceptable navigational signal' and I don't think this has anything to do with a clearance direct to a terminal fix in the circumstances being discussed in this thread.

Depending on distance from the IAF the considerations must surely be your safety altitude for that portion of the route and then the 25nm MSA.

Finally, if in doubt that you've been cleared out of the last assigned altitude - in this case FL80 - then ask ATC.

[galaxy flyer]

italia458

Intruder is incorrect, I've never heard of the MSA only being used for emergency.

There is a difference between US and Canada on this one--the FAA TERPS says that the MSA is for "emergency use only", it is not an operational altitude. One reason, in the US the MSA is not surveyed for signal coverage, nor does it guarantee it. Also, from a US Terpster, the MSA is not resurveyed unless there is a change in the basic procedure, hence, there is a possibility that an unsurveyed may exist in the off-route areas.

That is one reason why US ATCOs give the approach clearance with specific altitude instructions. Well, one of the reasons, those ATC instructions all came from the TW 514 accident.

That is US only, other countries have other ways of applying the MSA.

GF

[Intruder]

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.
If I didn't comprehend, I wouldn't have cited the VERY RECENTLY CHANGED differences in arrival procedure differences in the US and UK.

However, NOBODY here, including the French ATC, has offered ANY evidence that a descent below the already-cleared altitude/level is allowed on a direct-to clearance PRIOR TO the IAF. The exception for "cleared for approach" in Canada cited above is interesting, though I suspect it is used more in remote locations than as a routine procedure for airline operations into major airports.

If you have citations to show otherwise, please post them!

[Intruder]

ENR GEN 1.7 : Differences betweew ICAO and French Regulations
Good luck browsing that file
I did. There are no differences from ICAO procedures cited for descent clearances.

[Intruder]

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.
If true, where is it written?

[PBL]

PBL, yes, please ask your colleague for his input.

I did. He is away from posting until the end of the month, but if you can remind me again then I'll remind him.

PBL

[PBL]

[PBL: it is not clear to me that Intruder yet comprehends that not all procedures everywhere are the same....]
If I didn't comprehend, I wouldn't have cited ...

Thanks for clarifying. Per your request for citation, I just looked it up in Giemulla (the "Frankfurt Commentary", standard text) without success. I don't know where it is. I can ask.

PBL

[bookworm]

n 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.
...
If true, where is it written?

If it were written somewhere I could find, I wouldn't have said "it is generally believed". ;) However, this is from the CAA's CAP413 supplement (http://www.caa.co.uk/docs/33/CAP413Supplement.pdf)

"‘Cleared ILS approach’ may introduce an element of uncertainty as to when descent will be initiated because the pilot may descend to the final approach point altitude (platform height) at any time after receiving this clearance.’

There are also many threads on PPrune about the non-standard UK phraseology in which this aspect is discussed.

I believe that both interpretations are reasonable ones (without further clarification as in the AIM).

A clearance for the approach is an instruction to follow the vertical profile of the approach without further ATC instruction. Descent to subsequent levels is implicit. Why should that implicit vertical profile not start at the IAF with the charted altitude there?

Another example: I'm being vectored for an ILS at 3000 ft, a level above the charted FAP altitude of 2400 ft. The controller says "closing the localiser from the left, cleared ILS approach runway xx". I intercept the localiser and the glideslope comes in 2 miles before the FAP. May I descend? By your reasoning, I'm not on a published segment of the approach yet, so don't I have to wait until I reach the FAP before descending?

[ast83]

Of course you can. At 3000ft were cleared for the approach so once you're established on that approach you may descend with it. I think the more relevant question for the OP would be, can you descend to that 2400ft platform once cleared for the approach, perhaps even whilst still on an intercept heading?

Spud3, I understand you simply want to know if it's permissable. My common sense tells me it's not but it seems, I may be wrong. In the uk we are often cleared for the localised RXX, whenvestablished descend with the the GS. I always thought this was strange phraseology. Why not simply say cleared approach? Surely it's the same thing? Maybe this thread holds the answer, maybe a clearance for the approach does clear you to descend at your discretion implicitly. I'm yet to confim it either way. I'll continue the search.

[bookworm]

At 3000ft were cleared for the approach so once you're established on that approach you may descend with it.

Nope, you're not established on a published segment of the approach.

"The final approach segment begins at the final approach point (FAP). This is a point in space on the final approach track where the intermediate approach altitude/height intercepts the nominal glide path".

You're two miles further out than the FAP, and therefore not on the published final approach segment.

Of course, every pilot would descend on the glide, and every ATCO would ensure that such a descent was terrain-safe -- not difficult in this case, but it could create an issue at the extremity of coverage. I'm just pointing out that there are occasions when there is an implicit instruction to descend -- and spud3's case is arguably one of them.

[JeeHell]

maybe a clearance for the approach does clear you to descend at your discretion implicitlyI wouldn't go that far.
My reading of the text is when cleared for approach, you are cleared to descend while still observing the higher of MSA and approach altitude restrictions. After the IAF for sure at least (see second part of the post for before the IAF...).
In Spud3 case, the MSA is 2700ft in the north east until 18M then 2100ft everywhere else. The initial and intermediate approach are published at 2500ft. So, you may only descend to 2700 then 2500ft or 2500ft directly (depending on your arrival sector) and never below until you pass the FAP.

After thinking a lot about it, in this particular case I'm pretty sure the ATCO implicitly allowed further descent (to confirm, Spud3, it would be great to tell us what where your following actions and interactions with ATC).
Now in a more standard way, I'm pretty sure the approach clearance should come with a level/altitude UNLESS the last assigned level/altitude is compatible with the approach profile (meaning you won't go below that level before somewhere between the IAF and IF because of restrictions). Here FL80 is clearly not compatible since at KELON you should be FL050 max.

[spud3]

Jeehell,

IIRC, we were direct a vor at first, then cleared (or perhaps "route Kelon") to Kelon, all while in descent to FL 80. Cleared for app I think before we levelled at 80, perhaps after. We stayed level at 80 till at a point where the capt decided he wanted to descent. I advised atc we were leaving 80 for whatever the MSA was (dont have the chart right now). I think atc acknowledged, gave us the altm setting. No further altitudes or clearances given. Probably the next transmission was to contact tower at Kelon

[604guy]

The exception for "cleared for approach" in Canada cited above is interesting, though I suspect it is used more in remote locations than as a routine procedure for airline operations into major airports.


This terminology is in common use for airports in controlled airspace (in The Great White North) including those used routinely by airlines. While some of the larger airports that are covered under a terminal airspace environment will tend to have flight crews led by the hand to ensure maximum efficiency it is not unheard of even in those environments to get a “cleared for an approach” type of clearance in the wee hours of the night when traffic is at a minimum.

In Canada we also have the “100nm safe altitude” noted on all published approach procedures that allows flight crews to start a descent at least to that level once receiving a “cleared for an approach” type of clearance without having to be on an airway, air route, transition or within the MSA pie.

The other type of clearance we get here that can lead to some confusion among some foreign flight crews is “cleared out of controlled airspace via an approach to X”.

As for someone saying in an earlier post that ATC is responsible for terrain separation while receiving vectors, yes that is technically correct but hopefully he/she does have an awareness of the minimum safe altitude for their current position and their position in the near future. While our ATC brethren are, like pilots, very driven to zero tolerance for error, like pilots are human and subject to human error. I know that I have seen that particular error twice in my 40 years “at the wheel”.

I admit to thread creep and now return you to your original thread. :}

[BOAC]

Referring to my post #8, the phrase I have always used, whenever I have any doubt about such a descent or climb clearance (especially when treading carefully on unknown national sensitivities) is "Confirm unrestricted climb/descent?" - normally works a treat.

[Intruder]

A clearance for the approach is an instruction to follow the vertical profile of the approach without further ATC instruction. Descent to subsequent levels is implicit. Why should that implicit vertical profile not start at the IAF with the charted altitude there?

Another example: I'm being vectored for an ILS at 3000 ft, a level above the charted FAP altitude of 2400 ft. The controller says "closing the localiser from the left, cleared ILS approach runway xx". I intercept the localiser and the glideslope comes in 2 miles before the FAP. May I descend? By your reasoning, I'm not on a published segment of the approach yet, so don't I have to wait until I reach the FAP before descending?
First, I tried to find the cited approach on-line, but was unable, so I don't know what it looks like.

For many/most non-precision approaches, the IAF altitude is a "soft" (recommended) or an "at or above" altitude. If your cleared altitude is reasonable, even if above the minimum or recommended, you do not have any reason to descend below your cleared altitude. You may, however, need to configure the aircraft to obtain a steeper-than-normal descent profile from the IAF to the FAF. If it is a hard altitude, ATC has the responsibility to get you there.

In your example, you are being vectored to the localizer, which is a different situation. The FAF for an ILS is not always a fixed point, but is defined by Glideslope intercept after established on the localizer. if you intercept the localizer outside the nominal FAF depicted on the approach plate, you can descend on the Glideslope as long as you are within the service volume of the ILS. For example, look at the ILS to 06L at KLAX. Though the nominal FAF is at ALISN ([minimum] 1800' at 6.7 DME), there is a note that explicitly allows intercept of the GS as far out as NATHN ([soft] 3700' at 12.7 DME). ATC will often vector to intercept the localizer at some intermediate point/altitude, and you can intercept the GS if cleared for the approach.

[bookworm]

First, I tried to find the cited approach on-line, but was unable, so I don't know what it looks like.

IAPs (https://www.sia.aviation-civile.gouv.fr/aip/enligne/PDF_AIPparSSection/IAC/AD/2/1008_AD-2.LFOK.pdf) for Vatry.

Arrivals and Departures (https://www.sia.aviation-civile.gouv.fr/aip/enligne/PDF_AIPparSSection/ARR%20DEP/AD/2/1008_AD-2.LFOK.pdf) for Vatry.

[italia458]

There is a difference between US and Canada on this one--the FAA TERPS says that the MSA is for "emergency use only", it is not an operational altitude. One reason, in the US the MSA is not surveyed for signal coverage, nor does it guarantee it. Also, from a US Terpster, the MSA is not resurveyed unless there is a change in the basic procedure, hence, there is a possibility that an unsurveyed may exist in the off-route areas.

That is one reason why US ATCOs give the approach clearance with specific altitude instructions. Well, one of the reasons, those ATC instructions all came from the TW 514 accident.

That is US only, other countries have other ways of applying the MSA.

GF

Thanks for the correction! I didn't realize that.

[Intruder]

IAPs for Vatry.
After looking at the approach plate, it is even more clear to me that if I was cleared for the approach and direct to the KELON IAF at 8000', I would continue to KELON at 8000' and use the depicted holding pattern at KELON for descent to 2500'. One turn in holding with the landing gear down should be plenty, with 5 NM to the FAF to intercept the GS at 2500'.

Using the MSA of 2100' would put you below the 2500' [soft] initial approach altitude, so that would NOT be a good option IMO.

[JeeHell]

Intruder,

I'm quite certain that the hold entry is not permitted above FL50.
On the charts, there is written Zp=5000ft which means that the maximum altitude for entry is at FL50, otherwise you might enter AWYs, TMAs, MIL's zones etc where you're not supposed to be.

Anyway, the way the ATC reacted after their self-granted descent shows that it was at least implicit in the first message. I'm not saying it was correct :}

And using the MSA to descend on an approach doesn't mean you have to get down to it, I believe Spud3 wanted to use it as a reference for terrain clearance only.

[Intruder]

That's the first time I've seen a French govt approach plate, so I had no idea what Zp is.

However, if ATC cleared the airplane to KELON at 8000, then that airspace should be clear of interfering traffic.

[galaxy flyer]

Intruder

Compared to our ATC standards quite a normal way of doing business in Europe. I was inbound to Rome-Ciampino last week, cleared direct to CMP (VOR or NDB, I cannot remember, but NOT on the plate as either an IAF or a fix to a NoPT transition. And about 2 miles abeam the final course), about 135 degrees off the inbound approach course, as we approach CMP, Rome says, "cleared approach". I sort of expected such silliness, it was VMC and I'd seen this before. HDG mode, a swift cut at the inbound VOR approach course, ask the F/O to 'extend the line' and select APPR. Spot the field and fly a visual.

Anyway, why do European controllers do this kind of stuff? The OP should have been given an altitude along with that direct to the IAF with the approach clearance. The altitude should have been one recognizable on the plate and compatible with the approach. But, Noooooooo............

While I understand the maximum holding altitude, the difference in TAS between 5,000 and 8,000 cannot result in a spill-out of the airspace, even at maximum holding airspeed. And spilling out is better than a CFIT. Yes, the terrain here is likely forgiving, not always the case.

GF

OTOH, KTEB tower last month gave me traffic "over the Lincoln Tunnel". How is a pilot supposed to spot a tunnel from an airplane?? :ugh:

[Intruder]

I understand that it may be the normal way of doing business, but is it according to "the book"? IIRC, that's [part of] what the OP was asking.

I've also heard of the Italian "You know where you are? You know where you want to go? You cleared!" type of clearances. Under the right circumstances they are tolerable, but in hard IFR with a pilot who "hasn't been there before," it could be disaster...

So, I'm still waiting for the definitive French document that covers the situation...

[p51guy]

The 1970's TWA 727 Dulles crash into Round Hill, a high hill they flew into on the approach is when the US emphasized when cleared for the approach do not descend below any authorized arrival route altitude and if not on an arrival route maintain last assigned altitude until on an arrival segment even it means to the IAF.

[johns7022]

This reminds of going into Kelowna, CA years back...they cleared me for an approach, which has a holding pattern entry from the IAP..so I entered the procedure turn at last assinged alt, dropping into the IAP alt iin the hold, and did a full turn to get down onto the LOC...

So of course, I got ATC and planes asking me where I am constantly...in the procedure turn entry...out bound, in the turn, in bound...everyone is angry..

On the ground I asked 'what's up'....I guess as long as I was 'in protected airspace, I was suppose to decend in some kind of half ass entry at 5000 ft/mn and intercept the inbound course....

Either way I always assumed that a holding pattern procedure turn required a full circuit.....

I guess either way...what ever you do, it's better to be too high then too low....

[Intruder]

You only need to do the "full circuit" if time requires it. That defines the MAXIMUM protected airspace, not the required track. If you are cleared for the approach and can get down in a 360, then that's OK.

[JeeHell]

I guess you have no idea on how the protection zone of a hold is designed...
They have to take into account the different types of entries (direct, teardrop, etc), the wind drift, the accuracy of the hold fix (not the same if it's VOR, RDL-DME or RNAV based, and if it's in distance or time for the outbound leg length). Quite a lot of different factors.
And yes, the difference between FL50 and FL80 in terms of TAS may not be huge, but it still can make you go in another TMA. Where I work, it's a pain in the a** to locate holds because of that.

[Intruder]

The holding pattern at KELON is listed for 230 KIAS max at (according to your interpretation of Zp) 5000'. If cleared for the approach and needing to descend, it is likely that a pilot would extend some flaps and maybe the landing gear. So, a 180-200 KIAS hold is well within reason under the circumstances.

[BOAC]

Well, all really far too complicated! As I said in post #8, talk to ATC, point just west of KELON, dial in 2700' and arrange to be established on the STAR track inbound KELON just before it when you can then happily dial in 2500' and BINGO! No need for daring hold entries and 360s above hold level or whatever. KISS?

[InSoMnIaC]

I must say the most sense Anybody has made on this thread is Intruder.

Forget MSA's. Maintain 8000' until established over the IAF. if you need to descend before the IAF then request it from ATC.

I haven't seen the approach plate in question but from my experience in similar situations the controller clears you to an altitude that will allow you to conduct a Continuous Desecent Approach anyway. If they mess up and bring you high then ask for lower. simple as that.

[bookworm]

Well, all really far too complicated! As I said in post #8, talk to ATC, point just west of KELON, dial in 2700' and arrange to be established on the STAR track inbound KELON just before it when you can then happily dial in 2500' and BINGO! No need for daring hold entries and 360s above hold level or whatever. KISS?

That misses the point a bit, BOAC, as does the debate about the hold protection. There seems little doubt that aircraft should and usually do end up at KELON at about 2500 ft.

spud3 was given a direct routing when level or levelling at FL80, then given clearance for the approach.

If something similar happened under US rules, you would indeed "talk to ATC", and request descent, presumably more and more assertively as KELON approached.

If something similar happened under Canadian rules, you would follow the procedures that spud3 set out regarding descent, without the need to talk further to ATC.

The issue is whether under French rules (and more generally, other ICAO states' rules) the clearance for the approach either

a) is implicitly an instruction to descend (and if so, to what level?)

or

b) the clearance for the approach does not override the instruction to maintain FL80, and the controller should have issued an explicit descent instruction to get the aircraft down to 2500 ft at KELON.

Practically, with good comms with ATC, there was no problem. There rarely is when you have the chance to say to ATC "did you mean X or Y?" The clarification took place when spud3 reported leaving FL80 and the controller acknowledged, didn't correct. It gets more interesting if spud3's comms had failed after receiving the clearance!

[BOAC]

It gets more interesting if spud3's comms had failed after receiving the clearance! - well, if you are going to chuck in an R/T failure as well now, then as you will no doubt know there would be an urgent thumbing of Jepp or other docs to locate the 'French' procedure. Different ballgame.

As far as I can see, what I ASSUME spud did was to descend to 2700' initially, and having declared this 'leaving' to ATC - who did not issue any further instruction - I reckon that ticked all the boxes - safe and efficient. Why on earth enter a hold above its maximum altitude?

[Intruder]

Well, all really far too complicated! As I said in post #8, talk to ATC, point just west of KELON, dial in 2700' and arrange to be established on the STAR track inbound KELON just before it when you can then happily dial in 2500' and BINGO! No need for daring hold entries and 360s above hold level or whatever. KISS?
I agree with you in the respect that it's better to ask ATC for EXACTLY what you want, and confirm with them if there is any question or confusion.

However, I am addressing the OP's question regarding the clearance he got, not what else he might have requested. So far it appears that only Canada has the written procedure for what he thinks he wanted to do...

[Intruder]

The clarification took place when spud3 reported leaving FL80 and the controller acknowledged, didn't correct. It gets more interesting if spud3's comms had failed after receiving the clearance!
DANGER, WILL ROBINSON!!!

Don't forget that, in the US at least, ATC is no longer liable for their mistakes, including failure to correct pilots for wrong readbacks. Per an FAA publication a year or 2 ago (I forget the formal title/doc number), pilots are still liable for certificate action if they "break the rules," even with ATC's implicit consent.

[galaxy flyer]

BOAC

Well, here's a story that might illustrate why you would "maintain last assigned altitude until on a published segment". Inbound to NAS Rota, Spain (LERT) in the vicinity of the Martin VOR and in cloud, I was attending to physiological needs and didn't hear the clearance, but when I returned to the flight deck of the C-5, we were descending. It seemed a bit early to me, so I asked what altitude we were descending to and why so early. The two other pilots said Sevilla cleared us direct to Rota, descend to 4,000, report leaving FL70. I didn't like going down so early and told them to climb back to FL80, our last assigned level. Just as the words left my mouth, the GPWS sounded, "Terrain, Terrain". We climbed, I informed ATC that we would maintain FL80 until Rota. I also asked what the minimum instrument altitude was for the area and never got much of an answer, let alone an actual altitude.

Lesson: never, ever descend when off-route without being absolutely sure of the terrain. And then don't!

GF

[BOAC]

galaxy - what on earth was the point of that post? To tell me you had some muppets in the USAF? I knew that, I met some. I also met a lot of the good ones.

Quite honestly anyone who does what they did should not have been in the seat...and your last phrase was ridiculous!

[galaxy flyer]

BOAC

The point of the post should have been apparent in the first sentence--do not descend without knowing the terrain and your clearance. The OP was in EXACTLY the same position--direct, off-route to a fix except he only had FL80 as a level clearance, no specific descent clearance from ATC and no published route. My two muppets had an altitude clearance that was NOT appropriate for the terrain or distance from the field, but acted on that clearance, wrongly but the controller didn't give them any help.

having declared this 'leaving' to ATC - who did not issue any further instruction - I reckon that ticked all the boxes - safe and efficient. My guys did 'declare' leaving and did get an acknowledgment, hardly a safe and efficient.

Given that clearance to 4,000 feet by the controller, how was a crew supposed to know it would not be safe to descend? It was a bad clearance on the part of ATCO and bad airmanship on the part of the pilots.

As Intruder and I have been saying, published route or maintain your altitude or level until on one.

My two were summarily unqualified--one never to be an commander.

If my last sentence is "ridiculous", it is only because it rules out ANY descent when off-route which is a bit extreme, I suppose.

GF

[Pugilistic Animus]

Old Smokey* once gave advice that I now hold very close to my heart, in fact it is one of the best pieces of advice I've ever seen...for the air or ground


'Trust Nothing; Trust No One":suspect:


GF's post has a very important moral to it...CFIT has not died even with EGPWS







* where've you been?:)

[galaxy flyer]

One other point.....

Like lawyers, we have been batting this problem around for 4 pages, at our leisure. The Original Poster should NOT have been left in doubt what altitude to fly, in a speeding airplane, possibly over hazardous terrain. If the ATCO had issued this clearance, "Cleared direct to KELON, cross KELON at or above 2,500 feet (or whatever is appropriate for the case), cleared ILS 10", it would have been crystal clear what altitude to fly enroute to KELON.

TW 514, to any pilot in the US that remembers it, was one of the real influential accidents--it changed aviation. GPWS and EGPWS comes directly from that accident, as does a slew of FAA ATC changes, radar low altitude warnings and CRM. As I remember it, the FE was on the tape protesting the pilots decision to descend to the intermediate altitude when cleared by Approach Control.

There are lots of "out-of-the-way" airports where a clearance like the OP's and a descent based on the clearance could kill. The American and Canadian West have many such airports; no doubt the Alps, too.

GF

[aterpster]

galaxy flyer:

TW 514, to any pilot in the US that remembers it, was one of the real influential accidents--it changed aviation. GPWS and EGPWS comes directly from that accident, as does a slew of FAA ATC changes, radar low altitude warnings and CRM. As I remember it, the FE was on the tape protesting the pilots decision to descend to the intermediate altitude when cleared by Approach Control.

Alas, he didn't really protest, rather he questioned the altitudes on an IAP chart that did not meet U.S. chartings specifications (which required that the intermediate fix be in the profile view.)

I knew the captain quite well. <sigh> And, I was an ALPA rep on that seeming never-ending investigation.

You're right, that accident was a "deal changer," which included ICAO as well as the U.S. But, 35 years has passed so the wheel will likely be invented again, so to speak.

[john_tullamarine]

a bit of editing, merging and moving to tidy up. Unfortunately, this post ended up by me rather than the intending poster (76mike) .. apologies for the finger trouble on my part .. JT


Sorry; I'm still confused. Do we have a consensus on a reasonable answer for the VERY IMPORTANT question (and thread) "Descending once cleared for the approach"?

If I may restate the question: Say you're at 8000 feet. And the controller has told you to proceed direct to ABC VOR, and has cleared you for the approach. Also, say he has omitted an altitude to maintain. Finally, the approach plate says cross the VOR at 2500 feet.

When do you leave 8000 for 2500? Yes, we could ask the controller. Yes, we could be conservative, cross the VOR at 8000 feet, and then descend. However, in lieu of these two options, is there a "Textbook" answer?

Much thanks,
Mike

[hedgehog-in-fog]

Well, imho this discussion indicates that there's a question for icao, fsf: why we still don't have clear international procedures regarding the matter?:ugh:
Cfit, alar - that's fine but we have 4 pages of discussions on such a simple and live question:sad:

[PBL]

Well, imho this discussion indicates that there's a question for icao, fsf: why we still don't have clear international procedures regarding the matter?

Presumably for the usual, mundane reason that ICAO's members do not all agree on those procedures. As has become clear through contributions in this thread.

PBL

[BOAC]

4 pages of discussions- yes - amazing. Since we are forced to live in an imperfect world, ask (as per post #8). So simple - you don't need PPRune or ICAO or any other system. Just a mouth and a radio (an an ear to hear the reply of course). Countless times I have been given an ambiguous clearance. Either I know where I am and what is underneath me or I don't. Case 1 full procedural into the hold. Case 2 - you say 'Henri - am I clear unrestricted descent?' All the theoreticians and rule makers can take all the time in the world romanticising/sematicising over this, you have an aeroplane with limited endurance. It's called 'airmanship'. (Or was:ugh:)

[rudderrudderrat]

Hi BOAC,

I agree totally.

Using Airmanship: when within 25 dme CAV, request descent to an Altitude above MSA say 3,000 feet initially. Then establish straight towards Kelon, descending as appropriate iaw MSA / procedure.

see page 5 for ILS App @ Chalons VATRY (http://www.dircam.air.defense.gouv.fr/dia/PDF/IAC/IAC%20AD%202.LFOK.pdf)

[DFC]

There are quite a few issues causing confusion here and if they are removed then I think the solution is easy.

1. Bookworm spoke about the UK practice of ATC not using the phrase "cleared ILS". This highlights a misunderstanding on the Pilot side.

Remember that when Approach radar are vectoring the aircraft towards the ILS, the aircraft is in the initial approach phase - the vectors are replacing the procedure turn, base turn or other procedure designed for the initial phase and once established on the LOC it is in the intermediate phase and when it intercepts the glide path (at whatever altitude within the glidepath covereage) it is in the final phase of the approach.

Therefore that situation is not the same as the one described in the original post becasue in effect when put on the 30 degree leg and told "cleared ILS" the aircraft is already on the initial approach leg (in effect inside the IAF) and by definition can (and should be safe to in terms of terrain) descend to the intermediate altitude.

That is not the situation here.

2. A clearance has a start point and an end. In this case the clearance "cleared ILS Z" while enroute to the IAF ony has effect when the IAF is reached. This seems to not only be a problem in the arrival phase but has also caused problems enroute where for example aircraft within domestic airspace have received an oceanic clearance at say FL380 and have incorrectly climbed while in domestic airspace to FL380 without ATC clearance. So every clearance has a start and a finish and one can not pre-empt the start.

In this case, the aircraft was cleared to proceed from the IAF through the procedure all the way to the missed approach holding fix. Anything before the IAF was a separate issue.

3. Everyone is having a bit of tunnel vision with regard to MSA and terrain issues. What about other traffic and airspace issues. In terrain terms is may be safe to descend to 2500ft but will that cause the aircraft to leave controlled airspace, enter a restricted area or conflict with other traffic?

I would be interested to know what the inbound track to the IAF of the original poster was.

The only safe option in this case is to request descent when appropriate because "cleared ILS" being issues to an aircraft while enroute does not mean they can descend straight away.

Until the aircraft is established on the procedre then any levels approprioate to that procedure do not apply.

[bookworm]

Remember that when Approach radar are vectoring the aircraft towards the ILS, the aircraft is in the initial approach phase - the vectors are replacing the procedure turn, base turn or other procedure designed for the initial phase

To exactly the same extent as the "direct to KELON" clearance replaces the arrival segment.

If you believe that "cleared ILS" permits descent to the intermediate altitude, why do you not believe that the "direct to KELON" permits descent in accordance with the arrival?

[hedgehog-in-fog]

BOAC
I absolutely agree - ANY DOUBT - ASK.
But we have similar situations every day, they have to be clearly defined in international, not British or US regulations.

P.S.
from personal experience in ZBAA
ATC - niauoirjvnb....
P - say again, please
ATC - ffjvbriogiu...
P - say again?
ATC - rtoihyihjk...
P - confirm clear to land?
ATC - affirm!
P - thanks!:ok:

[BOAC]

they have to be clearly defined in international, not British or US regulations. - for 'have to' I suggest 'should be', and the point I am making is that when things are not clear, clarify and if that is still confusing and you are really not sure, then stick with a procedural approach. We cannot expect a perfect harmonised world.

In your quote I assume all you needed was clearance to land - you clarified and got it.

[DFC]

If you believe that "cleared ILS" permits descent to the intermediate altitude, why do you not believe that the "direct to KELON" permits descent in accordance with the arrival?


"Cleared ILS" when being vectored is given at a suitable point in the procedure where the flight has been placed correctly by the ATCO on an intercept with the intermediate phase of the approach and is in a position to descend to the level appropriate for the start of that phase (note that it is normally a level phase).

I never cease to be amazed by the number of pilots who are being vectored at 3000ft by ATC and on the 30 degree leg at 13nm are "clerared ILS" which triggers some irrational desire to dive as quickly as possible to 2000ft (the published platform level) despite the fact that they can establish on the LOC and have the required 2nm of established level flight before GS intercept - at 3000ft!!!!


Cleared direct to KELON is a lateral clearance alone and for example just because the minimum level on fro example an airway to KELON (which could be your IAF) is 2500ft you are most certainly not cleared to 2500ft simply becasue the ATCO cleared you to KELON.

As I pointed out - yes it is terrain safe and in this case it would be airspace safe (probably) but is it safe against opposite direction traffic then only ATC knows and they have not cleared you to change level.

When in the procedure eg in the case cited in the hold or at the IAF at FL80, ATC can not clear you for the procedure unless there are no other flights below you in the procedure. However, when 20 miles away inbound from say the south east at FL80 they can clear you to the IAF and clear you for the approach (becasue the procedure is empty) but climb a departure to FL70 straight at you.

They have issued you a clearance for the ILS procedure. They have not issued a clearance to descend until on that procedure.

Yes FL80 is very high to start the procedure and would perhaps be uncomfortable if doing it direct and not via a shuttle. However, until ATC clear you lower (which they may have planned) you do not know that it is safe to do so.

I will repeat that;

until ATC clear you to a lower level you do not know that it is safe to do so

Safety first.

[deefer dog]

do not bother to ask ATC for clarification - it makes too much sense.

do not use initiative, regulations and procedures are a preferred substitute.

before 25 miles, the concept of maintaining any altitude in excess of the lowest en route FL or altitude makes too much sense, as it is likely to avoid premature contact with terrain.

when inside the 25 mile MSA do not, descend down to the safe altitude, it is likely to make the approach segment and aircraft configuration too easy to manage

if it is possible to find a longer and more complex way of achieving the task of a straight in approach, explore all options, then you can write about them on PPRuNE

[bookworm]

until ATC clear you to a lower level you do not know that it is safe to do so

The entire point of this thread is about whether a clearance to a lower level is implicit in a particular clearance phraseology.

"Cleared ILS" when being vectored is given at a suitable point in the procedure where the flight has been placed correctly by the ATCO on an intercept with the intermediate phase of the approach and is in a position to descend to the level appropriate for the start of that phase (note that it is normally a level phase).

And one can equally argue that:

"Cleared ILS" when on a ATC-initiated direct segment to KELON is given at a suitable point in the procedure where the flight has been placed correctly by the ATCO on to commence the initial phase of the approach from the IAF and is in a position to descend to the level appropriate for the start of that phase.

2. A clearance has a start point and an end. In this case the clearance "cleared ILS Z" while enroute to the IAF ony has effect when the IAF is reached.

So if ATC has cleared me to an on-airfield IAF at 4000 ft above the airport and then uses the phrase "cleared visual approach", do you think that I'm required to fly to the IAF at 4000 ft before commencing descent on the visual approach?

As several posters have pointed out, the safety that you desire comes from clarity about the interpretation that should be placed on particular phraseology. Accidents come from situations where ATC and pilots interpret the same phraseology in different ways and circumstances prevent a timely clarification.