Descend to MSA when "cleared approach"

[president]

Imagine this:

You are cleared on a radar heading to 4000 ft and you are outside FAF on an ILS approach. Approach control clears on this heading for the ILS approach. Platform altitude is say 3000 ft at FAF. Can you legally descend to the MSA before you are established? I can imagine problems if you did that at certain busy airports. I would normally maintain 4000 ft until the glide. Some people told me that "cleared approach" allows you to descend to MSA and disregard the previous altitude clearance. Opinions ?

[squawkident.]

Good question. My take is:

1) If you were on a published arrival (STAR) and were cleared for the arrival initially, then further cleared to onto the ILS, then you can descend with the published arrival, which presumably would be 3000feet. Note, you must still maintain all step down height constraints as published.

2) On a radar heading the arrival is no longer in use. Therefore you cannot descend below the cleared altitude. At 4000, you need to be intercepting from at least 14nm away from glideslope. If you are being vectored inside that, ask for a lower altitude, reduce speed, configure early, be prepared to intercept from above and and above all, be prepared to ask for extra miles and go around.

3) Depending on your company, if VMC, you may ask for a visual approach whereby you can then descend at your 'leisure'. However you are not then cleared for the ILS approach, even though you will be using it as a reference.

Note, due terrain, some airports simply won't be able to descend you lower until you are clear of terrain. In this case, ATC should notify you 'standby for further descent'.

Hope that helps

[Chesty Morgan]

In Spain, at least, once you are cleared for the approach you may descend to the platform altitude.

[president]

I'm with you on the STAR and request visual. It was not the piloting techniques I was after. The question was regarding case number two. On radar vector with altitude clearance and "cleared approach". Can you legally descend to MSA ? Why, or why not ?

Regarding descending to platform altitude (which could be below MSA) in Spain, where does it say that? I think you risk busting your terrain clearance.

On radar vectors ATC is responsible for your terrain clearance, as we know. Also for vectoring below MSA. What authorises you to leave the cleared altitude, because ATC says "cleared approach"? You could have a mountain below you but above platform altitude, between you and the FAF






Good question. My take is:

1) If you were on a published arrival (STAR) and were cleared for the arrival initially, then further cleared to onto the ILS, then you can descend with the published arrival, which presumably would be 3000feet. Note, you must still maintain all step down height constraints as published.

2) On a radar heading the arrival is no longer in use. Therefore you cannot descend below the cleared altitude. At 4000, you need to be intercepting from at least 14nm away from glideslope. If you are being vectored inside that, ask for a lower altitude, reduce speed, configure early, be prepared to intercept from above and and above all, be prepared to ask for extra miles and go around.

3) Depending on your company, if VMC, you may ask for a visual approach whereby you can then descend at your 'leisure'. However you are not then cleared for the ILS approach, even though you will be using it as a reference.

Note, due terrain, some airports simply won't be able to descend you lower until you are clear of terrain. In this case, ATC should notify you 'standby for further descent'.

Hope that helps

[RAT 5]

Let's get practical. You ask the question on here as to what you can do, or not. If in doubt ask ATC not prune. You are cleared, on HDG, to 4000' and cleared approach. This would suggest you are cleared to intercept the final track and descend on the procedure from 4000'. If you feel you will intercept the final track too close for 4000', i.e. be above the profile, you would ask ATC for further descent. If 4000' is OK for the distance at intercept there is no problem. It is not uncommon for ATC to forget to give you further descent, but is it necessary? Remember the PIC is responsible for navigating the a/c to a safe approach to landing. ATC is responsible for terrain clearance, but PIC has final responsibility for managing the energy and safety of their a/c. Situational awareness is the crew's responsibility. ATC can screw up as easily as you.

[BleedingAir]

I agree with RAT 5 above. The part of the world I fly in, the answer is no. A clearance to 4000' followed by an approach clearance is a clearance to descend not below 4000' until established on the approach. If this will leave you high on slope, ask for further descent or a different vector. Joining an approach off a STAR shouldn't be an issue.

Can't speak for other parts of the world though.

[Chesty Morgan]

Regarding descending to platform altitude (which could be below MSA) in Spain, where does it say that? I think you risk busting your terrain clearance.


Can't remember, try the Spanish AIP. You can safely assume that the platform altitude is above the surrounding terrain and that where ATC clear you terrain will not be an issue.

What authorises you? That's what's they expect you to do!

[galaxy flyer]

In the US, TW514 smashed into a ridge doing just this. Now, the approach clearance will be, "Turn (heading), maintain xxxx until intercepting, cleared ILS" or "maintain xxxx until established on a segment of the approach, cleared for approach". MSAs are sometimes procedural, sometimes emergency only.

GF

[president]

Just to be clear. I know how to deal with energy, approach and landing. I am not looking for piloting advise. I am asking whether something is legal or not. Anybody with a legal reference ?

[RAT 5]

You can safely assume that the platform altitude is above the surrounding terrain and that where ATC clear you terrain will not be an issue.

And if you are not under radar???

[Piltdown Man]

I'm basically with Rat here and especially with his "if you are not sure, ask ATC" comment. But this is an unambiguous clearance. You have a heading, a level and clearance to join the ILS in the traditional way; localiser first. If you need a descent to allow an intercept of the localiser first you should ask for it. You were not cleared to descend to an intermediate level first.

The times when this type of clearance can become confusing is when you are on a heading to join an arrival procedure and at the same time cleared for the approach. This can happen in places like Marseille, Gothenberg, Alessund, Trondheim etc. Here you will be flying on own own below MSA (on an Arrival or Transition) and be responsible for your own let down (but according to the step down fixes on your charts). But you may descent because you have been cleared to do so.

PM

[RAT 5]

Piltdown: Indeed. At BGY you start the approach at a FL over the VOR. You descend outbound to an Altitude and turn in descending further after a DME is passed, then intercept the ILS. Common for ATC to clear you to the VOR at FL and "cleared for approach". Why should radar talk you round & down the procedure? You follow the chart and they monitor you. Quiet, calm, relaxed and allows radar to give their attention to all traffic.
However, it was not uncommon for some airline crews, who were more used to being 'led by the hand', to ask, "can we descend?" ATC "you are cleared approach call finals." Only for the a/c to repeat the question. I guess confirming is safer, even twice, but which part of cleared approach from the VOR didn't you understand? May sound harsh, but it takes up radio time and makes one wonder.

[Chesty Morgan]

You can safely assume that the platform altitude is above the surrounding terrain and that where ATC clear you terrain will not be an issue.

And if you are not under radar???

Then you'd be either visual or procedural. If you're procedural are you going to ignore level restrictions on the arrival and approach?

[RAT 5]

Agreed.........

[aterpster]

president:

Just to be clear. I know how to deal with energy, approach and landing. I am not looking for piloting advise. I am asking whether something is legal or not. Anybody with a legal reference ?

As GF stated, it caused a CFIT for TWA 514 in 1974. Caused a regulatory change in the U.S. to maintain last assigned altitude until on a published route or segment of an approach. Also, in the U.S. MSAs are for emergency use only.

I've been in this business for a long time and this is the first time I've heard the term "platform altitude." That's not termed used in the U.S. Perhaps it is elsewhere. Do you know if there is an ICAO definition?

[vilas]

What Piltdown has said is correct. You don't descend below cleared altitude unless cleared for full procedure on a published track like IAF to IF or fix with published descent altitude.

[aterpster]

GF:

In the US, TW514 smashed into a ridge doing just this. Now, the approach clearance will be, "Turn (heading), maintain xxxx until intercepting, cleared ILS" or "maintain xxxx until established on a segment of the approach, cleared for approach". MSAs are sometimes procedural, sometimes emergency only.

Attached is the chart used by the crew of TWA 514 on December 1, 1974.

Also, as you say, MSAs are not operational altitude in some countries. The U.S. is one of them. Also attached is a current RNAV approach in my area (KF70). The FAA discontinued sectorization of MSAs on RNAV charts. Note the altitude of the MSA and the profile altitudes of the procedure.

[Intruder]

In the US, maintain last cleared altitude until established on an approach. FAA AIM Sec. 5-4-6:e. The following applies to aircraft on radar vectors and/or cleared “direct to” in conjunction with an approach clearance:
1. Maintain the last altitude assigned by ATC until the aircraft is established on a published segment of a transition route, or approach procedure segment, or other published route, for which a lower altitude is published on the chart. If already on an established route, or approach or arrival segment, you may descend to whatever minimum altitude is listed for that route or segment.
Sec 5-4-7:b. When operating on an unpublished route or while being radar vectored, the pilot, when an approach clearance is received, must, in addition to complying with the minimum altitudes for IFR operations (14 CFR Section 91.177), maintain the last assigned altitude unless a different altitude is assigned by ATC, or until the aircraft is established on a segment of a published route or IAP. After the aircraft is so established, published altitudes apply to descent within each succeeding route or approach segment unless a different altitude is assigned by ATC.

To reiterate that the use of MSA is NOT allowed in this case, Sec 5-4-5 says:c. Minimum Safe/Sector Altitudes (MSA) are published for emergency use on IAP charts.

[Sidestick_n_Rudder]

Can anyone explain what it means "MSA is for emergency use only"? MSA is MSA, if you fly above it you won't hit anything - emergency, or not. What am I missing here? :confused:

[westhawk]

What am I missing here?


Just that the US meaning of the term differs from what you are probably used to. Not to derail the thread any further, but in FAA parlance, MSA is not a procedural altitude. It is merely an altitude which should keep you out of the weeds if you are off the procedural track and within 25 nm of the NAVAID depicted.

From FAR 97.3

MSA means minimum safe altitude, expressed in feet above mean sea level, depicted on an approach chart that provides at least 1,000 feet of obstacle clearance for emergency use within a certain distance from the specified navigation facility or fix.

[president]

@ aterpster,

platform altitude is just a slang for initial approach altitude. heard that it originates from the uk. ICAO do refer to the term on top page 9 in this doc. But it´s nothing official.

http://www.icao.int/safety/RunwaySafety/Documents/Unstable%20Approaches-ATC%20Considerations.pdf

[FlightDetent]

Just that the US meaning of the term differs from what you are probably used to. Not to derail the thread any further, but in FAA parlance, MSA is not a procedural altitude. It is merely an altitude which should keep you out of the weeds if you are off the procedural track and within 25 nm of the NAVAID depicted.

From FAR 97.3 Quote:
MSA means minimum safe altitude, expressed in feet above mean sea level, depicted on an approach chart that provides at least 1,000 feet of obstacle clearance for emergency use within a certain distance from the specified navigation facility or fix.


Interesting. I noted the reference to AIM in the previous post too, different ways to skin a cat.

For where I come from (both training and operations) MSA is calculated in the same manner, providing 1000 ft obstacle clearance. Given the fact, that intermediate approach segment MOC is 500 ft - just for comparison, I am happy to use MSA as an operational altitude when the situation of the day requires to do so.

This would be illegal in the US, ok. Learn something every day: ticked.

[aterpster]

president:

Thanks for the reference. I quote the pertinent language:

An aircraft can either self position for an approach or be vectored. Before leaving the Initial Approach Altitude (also known as Platform Altitude) the aircraft must be lined up with the runway and at an appropriate distance. If the aircraft is not in the correct position the final descent can not be commenced as the aircraft may be outside of the protected area, hence terrain separation can not be assured. A descent at this point would be dangerous, particularly if in Instrument Meteorological Conditions.

I am not sure what the author is trying to say. In any case, it would nave no application in FAA controlled airspace. We learned the lesson the hard way with the TWA 514 CFIT. Those AIM cites above, are almost verbatim quotes of federal aviation regulations written after TWA 514.

[aterpster]

FlightDetent:

For where I come from (both training and operations) MSA is calculated in the same manner, providing 1000 ft obstacle clearance. Given the fact, that intermediate approach segment MOC is 500 ft - just for comparison, I am happy to use MSA as an operational altitude when the situation of the day requires to do so.

This would be illegal in the US, ok. Learn something every day: ticked.

A further bit of clarification. In TERPs, and I presume in PANS-OPS as well, required obstacle clearance (ROC) in feeder routes and airways must have at least 2,000 feet of ROC in Designated Mountainous Areas (DMAs) and 1,000 feet elsewhere. MSAs always have 1,000 feet, even in DMAs, which makes them especially non-operational in DMAs.

The FAA is going increasingly to Terminal Arrival Areas (TAAs), which are operational altitudes that replace MSAs and have 2,000 feet of ROC in DMAs. TAAs don't fit everywhere because they have to meet descent gradient requirements (MSAs don't) and the affected ATC facility has to sign off on TAA procedures. Attached is am example of a TAA procedure. (Some other countries are also using the TAA concept instead of MSAs, at least with some procedures.)

[Zaphod Beblebrox]

My take on this is No you many not descend to the MSA. I base this answer on the following:
(US rules only)

14 CFR 91.175 - Takeoff and landing under IFR

(i) Operations on unpublished routes and use of radar in instrument approach procedures. When radar is approved at certain locations for ATC purposes, it may be used not only for surveillance and precision radar approaches, as applicable, but also may be used in conjunction with instrument approach procedures predicated on other types of radio navigational aids. Radar vectors may be authorized to provide course guidance through the segments of an approach to the final course or fix. When operating on an unpublished route or while being radar vectored, the pilot, when an approach clearance is received, shall, in addition to complying with § 91.177, maintain the last altitude assigned to that pilot until the aircraft is established on a segment of a published route or instrument approach procedure unless a different altitude is assigned by ATC. After the aircraft is so established, published altitudes apply to descent within each succeeding route or approach segment unless a different altitude is assigned by ATC. Upon reaching the final approach course or fix, the pilot may either complete the instrument approach in accordance with a procedure approved for the facility or continue a surveillance or precision radar approach to a landing.

Different countries may have different rules but in the US there was a famous accident at Washington Dulles. A TWA 727 crashed short of runway 13. It was a CFIT accident where the aircraft descended to the initial approach altitude while on vectors. There was ridge line between the aircraft's position and the runway and they hit just below the crest. This was after cockpit voice recorders but before ground proximity warning systems.

[JammedStab]

The answer is....it depends on the country.

[A Squared]

In the US, TW514 smashed into a ridge doing just this.

Actually, no they didn't, they descended well below the MSA. If they had remained at the MSA, they wouldn't have hit anything. From the chart ATERPSTER posted, I believe the relevant sector MSA was 3300 MSL. If not it was 2600 MSL Either altitude would have kept them clear of terrain. The hill they hit was slightly less than 1800 ft MSL

[galaxy flyer]

The OP's proposition was to descent to "platform" altitude upon receipt of the approach clearance--which exactly what TW 514 did, such as a platform existed. And when would suggest they left 3300 feet? Besides, TERPS does not authorize the MSA as an operational altitude and it was trained that way, in any case.

GF

[AerocatS2A]

No, the OP mentions the platform altitude but their actual proposition is to descend to the MSA, which may or may not be ok depending on where you are flying. Where I fly, it is not ok, we are expected to maintain the last assigned altitude until on the approach. Descending below the MSA in IMC would be stupid regardless of where you are flying.

[winterOPS]

I am also curious of this question. How ever I cant find a legal reference amongst the answers. I think the question is within "EASA land" tough... and therein it might by divided as EASA regulation and/or national regulations.

During training I learnt that once cleared for approach you can follow the altitude restrictions stated on the plate how ever if I recall it correctly every time this happened it was coupled to an arrival route. So this option everybody more or less agree on

How ever the question, under radar vectors could you apply this or not? And if yes where does it legally say so...

if looking though Eurocontrols "ICAO Phraseology Reference Guide / ALL Clear" it does imply that you may not descend below cleared altitude even tough you are cleared for approach.

So, if vectored "too high" for intercept from below ask for descend...

Have a look at page 17

http://www.skybrary.aero/bookshelf/books/115.pdf


Might this be a question to rise on the ATC forum as well?

[oggers]

"You know, according to this dumb sheet it says thirty four hundred to Round Hill --- is our minimum altitude..[but]..when he clears you, that means you can go to your initial approach altitude." Said the captain of TWA514 as he passed 3000' descending 1800', 30 miles out in the mountains of Virginia on 'approach' to Dulles.


Well as GF, aterpster and intruder have explained the FAA have nailed this one. You cannot leave assigend alt until established.

Despite suggestions it may be kosha in other countries, nobody has come up with a single reference to back that opinion. So the answer is still no.

On the other hand a 'cruise clearance' (USA again) clears the pilot for the approach and descent to MEA at pilots discretion. But you don't get one of those whilst being vectored.

[Checkboard]

In the UK, the Manual of Air Traffic Services (CAP 493), says:

The controller shall use one of the following techniques when issuing a clearance to the pilot to descend on the ILS/MLS glidepath:




(1) Clear the pilot for the ILS/MLS approach only if a descent instruction has been issued to the level published in the ILS/MLS instrument approach procedure at the final approach fix, or to a lower level permitted by the aerodrome’s SMAC; or
(2) Issue a conditional clearance to the pilot to descend on the ILS/MLS glidepath once established on the localiser; or
(3) When it is necessary to ensure that an aircraft joining the ILS/MLS does not commence descent until specifically cleared, solely instruct the pilot to report established on the localiser and to maintain the previously assigned level. Subsequently, the pilot shall either be cleared to descend on the glidepath or given appropriate alternative level instructions.



So you should (in the UK) never be given "Cleared Approach", unless you have also been cleared to descend to the platform altitude (precisely due to this confusion). You should (in your example), if you are cleared to descend to 4000' and intercepting an approach with a 3000' platform, be cleared "once established, descend with the glide". In other words - the 4000' is limiting until conducting the approach - i.e. on the glidepath.

This is because the approaches are surveyed with regard to terrain clearance, but not necessarily airspace. You may thus have a 2500' platform shown on the plate, but the lower limit of controlled airspace is 3000' and VFR traffic may be transiting under arriving traffic at 2500' outside controlled airspace.

[RAT 5]

Are you ever cleared for 'Approach', unless visual? Are you not cleared for an ILS, or VOR, or RNAV, or NDB approach. Is there not always a suffix? Often there is a request to call established on the final track, and then given descent clearance from your last cleared ALT. IT maybe you'll be cleared to establish and then descend, but always on the XYZ type of approach aid.

[A Squared]

The OP's proposition was to descent to "platform" altitude upon receipt of the approach clearance--which exactly what TW 514 did, such as a platform existed.

Again, no, it is not. "platform" altitude is an unofficial term which apparently may mean different things to different people, and it has absolutely no meaning in the context of US TERPS. It is significant that aterpster, one of the more knowledgeable people in the US about TERPS issues had never heard of "Platform Altitude".

There are some pretty broad clues what the OP meant when he said "platform altitude". I'll quote them for you. The first is the thread title:

'Descend to MSA when "cleared approach"'

Then in the original post, tha actual question being asked:

" Can you legally descend to the MSA before you are established? "

Did you notice that "MSA" keeps popping up?

That’s what the question is about; descending to MSA and that's not what caused TWA 561 to crash. They descended below MSA to the intermediate approach altitude. You'll notice that nowhere does the OP suggest or asking about descending to an intermediate altitude prior to being established on that intermediate approach segment.

And when would suggest they left 3300 feet? Besides, TERPS does not authorize the MSA as an operational altitude and it was trained that way, in any case.
GF

I never claimed it was legal to descend to MSA in the US. As others have pointed out it's not a procedural altitude in the US I'm only saying that if they had descended to the relevant MSA and maintained that altitude until established on the approach, (which is what is being proposed by the OP) they would not have crashed. That's not a trivial distinction.

[A Squared]

Despite suggestions it may be kosha in other countries, nobody has come up with a single reference to back that opinion. So the answer is still no.

Here's one. Transport Canada AIM RAC 9.3.

A 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;

(c) minimum sector altitude (MSA) specified on the appropriate instrument approach chart;

(d) safe altitude 100 NM specified on the appropriate instrument approach chart;
or

(e) when in airspace for which the Minister has not specified a higher minimum, an altitude of at least 1 000 ft above the highest obstacle within a horizontal radius of 5 NM (1 500 ft or 2 000 ft within designated mountainous regions, depending on the zone) from the established position of the aircraft.

Doesn't get much clearer than that.

[RAT 5]

I interpret this Canadian text to mean: you are cleared for an approach of whatever type. You can descend at pilots' discretion so as to safely establish on the approach at a safe altitude. You are responsible for determining what that is. The criteria are written down.

No where in that text are you operating at an ATC cleared altitude (below your cruise level) on a commanded heading to establish on the final track. It's not quite apples & apples.
However, your example might be concentrating on the 'MSA' element of the text. If so I defer to you.

[aterpster]

A Squared:

I never claimed it was legal to descend to MSA in the US. As others have pointed out it's not a procedural altitude in the US I'm only saying that if they had descended to the relevant MSA and maintained that altitude until established on the approach, (which is what is being proposed by the OP) they would not have crashed. That's not a trivial distinction.

Having been trained many times by the same training department that trained the TWA 514 crew, I doubt they had any training on MSAs, or even how to pick them off the Jepp chart (which portrayal of MSAs was quite bad in those days.) They focused on three critical altitudes in the plan view leading to ROUND HILL. Had they selected any one of those three altitudes as their minimum altitude until ROUND HILL, they would have been home free. Some on the accident investigation team speculated that the ride was so bad they wanted to get down. No one will ever know if that was in the captain's mind.

[oggers]

Here's one. Transport Canada AIM RAC 9.3.

A 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;

(c) minimum sector altitude (MSA) specified on the appropriate instrument approach chart;

(d) safe altitude 100 NM specified on the appropriate instrument approach chart;
or

(e) when in airspace for which the Minister has not specified a higher minimum, an altitude of at least 1 000 ft above the highest obstacle within a horizontal radius of 5 NM (1 500 ft or 2 000 ft within designated mountainous regions, depending on the zone) from the established position of the aircraft.

Doesn't get much clearer than that

That is what happens during own navigation from the en-route phase. That does not say you can leave your assigned altitude before established whilst being vectored to final.

The OP's question was specifically: can you leave assigned altitude whilst on a vector to final before becoming established. In the USA it is absolutely clear that you cannot. There is still no reference here to indicate it is legitimate to do so anywhere else.

Whilst being vectored ATC are responsible for terrain clearance. The changeover of responsibility back to pilot occurs not when you are cleared for the approach but when you hear the key words "resume own navigation". In the case of vectors to final (the case in point) you are not told to resume own nav but it stands to reason the point you resume responsibility for terrain avoidance is when established.

I am no longer surprised that the FAA have to spell this out every time a pilot is vectored to the ILS.

[aterpster]

oggers:


I am no longer surprised that the FAA have to spell this out every time a pilot is vectored to the ILS.

That is not the case. The regulations and related policy guidance were significantly changed in 1975 as a result of the 1974 TWA 514 CFIT.

That was 41 years ago. Everyone figured out what the 41 year old regulatory change meant.

[oggers]

...my point is that because of that accident you are reminded to "maintain [assigned altitude] until established" when you are vectored to intercept the localiser. As opposed to assuming you will maintain it. This thread has convinced me that is a wise move by the FAA.

[aterpster]

oggers:

...my point is that because of that accident you are reminded to "maintain [assigned altitude] until established" when you are vectored to intercept the localiser. As opposed to assuming you will maintain it. This thread has convinced me that is a wise move by the FAA.

Indeed it was. The circumstances of the accident were more complex. The flight was coming from KIND. Washington Center cleared the flight to intercept the AML 301 radial some 35 miles from the airport and descend to 7,000. Then the center handed the flight off to Dulles Approach Control. The Approach Controller issued no lower altitude. He simply cleared the flight for the approach. Had they maintained 7,000 to the final approach fix they would have been about 5,000 feet too high. So, they were caught with a lousy clearance and a deficient approach chart.

[piratepete]

PLATFORM ALTITUDE.
If you are from UK or have worked in a company run by Brits you know instantly what "platform altitude" means.For the rest of us it is the initial published altitude on an instrument approach chart from where you commence your final descent at the FAF......typically for a sea level airport its something around the 2-3000 feet amsl area with QNH set.Peter.

[pukeko]

Looks like ICAO are trying to tackle it too.

This is in the amendment to Doc4444 effective next month:
8.9.4.2 When clearance for the approach is issued, aircraft shall maintain last assigned level until intercepting the specified or nominal glide path of the approach procedure. If ATC requires an aircraft to intercept the glide path at a level other than a level flight segment depicted on the instrument approach chart, ATC shall instruct the pilot to maintain the particular level until established on the glide path.

Plus a whole heap of stuff about climb/descent on SIDs/STARs.

[RAT 5]

Considering that, perhaps, the majority of pilots reading this do not have English as their first language I think they should make text as simple as possible and avoid questions. (a comment I made to some previous airlines where many crew notices needed 3 or 4 readings, and even then.......?)

The first sentence is an instruction to the crew. Maintain last assigned level by ATC. Clear. It doesn't matter if this is above the 'level flight chart segment' or not.

The 2nd sentence is an instruction to ATC. If they want the crew to maintain a level above the 'level flight chart segment' they have to instruct the crew. i.e. back up the SOP of the 1st sentence.

I suppose it could be called belt & braces; but when reading both sentences it make me wonder if I misunderstood the first one. That seemed as clear as could be.

Am I missing something?

[Viper 7]

When we are on vectors in Canada and cleared for an approach we can descend as described in the TC AIM quote posted previously.


If we are on vectors below MSA but at or above min vectoring altitude, we will normally get "On interception, cleared the straight in ILS XX approach."


I can't recall being on vectors and subsequently being "cleared out of controlled airspace for an IFR approach", but getting this app clnc off of a PPos Dct GPS enroute phase happens quite regularly at the uncontrolled fields up here.


Maybe the hugemongous holes in our radar coverage is the reason for the flexibility in our rules?


;)

[N1EPR]

In the past it was noise abatement.


I haven't flown for many years but in my day it was not uncommon to receive a vector that would take you to the OM along with a clearance - cleared for the approach. The last assigned altitude was well above the glide slope intercept altitude at the OM.
The controllers procedures did not allow descent below that last assigned altitude due to noise abatement in the area of the vector. Thus the pilots had to start a descent before intercepting the approach path in order to make a normal descent to the airport. This was most prevalent in NY, Washington and other high density areas.


It was still common to receive these types of clearances when I retired in 1998.

[ALBATROS]

Hello everybody,
First in Spain we apply EASA and ICAO rules, maybe in FAA or in UK has something slightly different.

FROM ICAO, clear for the app means that you are clear for both lateral a vertical navigation but you can start your descend if you are within 5 degrees or half of the max LOC desvistion (I'm saying this by memory so the wording could be different).

Also, if the ATC want you to maintain the altitude way after the loc interception they should say it like they do it Le Bourget, they clear you for the "LOC only" maintain the altitude until you are advised by the ATC that you can start your final descent.

If you are expecting to achieve the LOC too high you should request descend to the ATC.

This is my humble opinion because I haven't seen anything written telling you that you can leave the altitude assign by the ATC until established.

[pa12 pilot]

The FAA discontinued sectorization of MSAs on RNAV charts.
If you mean that the MSA circle is never split into pieces, with different altitudes in the different pieces, you are mistaken. [Maybe you meant something else?]

Have a look at the RNAV approaches at the following airports and you'll see what I mean: PASH, PAIW, PAOM, PAGL, PFEL. These are just a few examples.

[oggers]

pa12 pilot, having just checked every RNAV app on that list there were only two that had MSAs and both of those were non-sectorized like aterpster said. All the others had TAAs. You know there's a difference right?

[pa12 pilot]

Let me back up, because I was reading "MSA" and my brain was thinking "TAA."

Here's what the AIM says:

5. Altitudes published within the TAA replace the MSA altitude. However, unlike MSA altitudes the TAA altitudes are operationally usable altitudes.

And:

(a) An ATC clearance direct to an IAF or to the IF/IAF without an approach clearance does not authorize a pilot to descend to a lower TAA altitude.

And:

(b) Once cleared for the approach, pilots may descend in the TAA sector to the minimum altitude depicted within the defined area/subdivision, unless instructed otherwise by air traffic control.

Forgive me for having taken us down a detour.

[aterpster]

TAAs and FAA MSAs are two quite different criterion.

[oggers]

Forgive me for having taken us down a detour.

Ok thanks for clarifying.

[aterpster]

Here is an example of a useless MSA on an FAA RNAV approach: