"Cleared for the ILS approach, runway__"

[A.FLOOR]

Can anyone explain what the pilot is permitted to do(speeds/altitudes) when he hears these wods from ATC in the following situations.

1. On a published STAR, with altitude and speed constraints at various waypoints

2. On a heading, to intercept the localizer.

Thanks

[MrBernoulli]

This is a general answer with a military slant, without going into too much detail:

1. Fly the approach as per the plates and intercept the ILS (possibly call "localiser established" and "glide path descending" at the appropriate points) and await freq changes (unless plate specifies where to do so) and landing clearance. If no landing clearance then perform missed approach procedure on the freq indicated.

2. Probably maintain that heading to ILs intercept then as above.

[bookworm]

Presumably the particular issue is whether the pilot is permitted to:

a) descend immediately to the depicted altitude at the IAF

b) change heading as required to intercept in case 2

c) ignore the STAR altitude/speed constraints on the basis that they have been overridden

?

PANS-OPS and PANS-RAC appear remarkably silent on the issue. The FAA's AIM (5-4-6) is more explicit:


An aircraft which has been cleared to a holding fix and subsequently "cleared . . . approach" has not received new routing. Even though clearance for the approach may have been issued prior to the aircraft reaching the holding fix, ATC would expect the pilot to proceed via the holding fix (his/her last assigned route), and the feeder route associated with that fix (if a feeder route is published on the approach chart) to the initial approach fix (IAF) to commence the approach. WHEN CLEARED FOR THE APPROACH, THE PUBLISHED OFF AIRWAY (FEEDER) ROUTES THAT LEAD FROM THE EN ROUTE STRUCTURE TO THE IAF ARE PART OF THE APPROACH CLEARANCE.

[411A]

You are most definately not allowed to descend to the IAF/FAF altitude. TWA tried this with a B727 many years ago approaching IAD (I think) and found to their dismay rather high ground in the way.
No one survived.
Follow the lead in routes indicated on the chart, that is what is expected by ATC, unless cleared otherwise.

[noflow]

You have to maintain the last assigned altitude until established on the approach.

[OzExpat]

In case 1, I would follow the STAR to the FAP, abiding by all applicable ALT and IAS limits. If the ALT limit is restrictive for GP intercept, I'd be asking for some descent (I'm assuming, in this case, that the ALT limit is imposed by ATC rather than the STAR, of course). At the FAP, I would then make the ILS approach.

In case 2, I would make the intercept on the currently assigned intercept heading and execute the approach.

[bookworm]

In case 2 I would think you are cleared to decend to the published intercept altitude and continue the ILS or simply intercept without further complication and fly the ILS.

So what's the published intercept altitude then? The altitude at the little cross on the plate (FAP)?

[Semaphore Sam]

My understanding is that, prior to the TWA accident at IAD that 411A referred to, there was a common understanding that a clearance for an approach included a clearance to descend to the IAF altitude; this particular accident changed this. In fact, prior to this accident, one would be criticized, at least in the military (MAC), if one did NOT descend to the IAF altitude when cleared for an approach.

[deadhead]

When you are cleared for an approach, your descent is unrestricted (unless ATC put one in). This does not mean diving toward the IAF/FAF/FAP altitude - it means this:

1. If on vectors, maintain LAST ASSIGNED ALTITUDE until established on the procedure - then descend according to that procedure. The reason you maintain the last assigned is because when under vectors, ATC provide terrain clearance to the point you can continue with a pilot interpreted aid.

2. If not on vectors, then YOU provide the terrain clearance so descend not below published minimum descent altitudes directly underneath you at any time until established on the approach - thenm as per the published profile. Obviously you might be tracking procedurally via a STAR, AREA or ERC chart etc. The MSAs are on those!

[None]

It has been said that when uncertain about what a clearance allows, it is wise to remain on the thick black lines on the Jeppesen charts (situation 1). This is essentially what many of the above posts are saying. dh states what is emphasized in every training program.