for example “intercept the localiser, when established descend with the glide path”
I heard that few times, I wonder how many pilots out there descend on “glidepath” before being established…I am sure it means don’t descend on any “vertical profile” until established (different to don’t descend on glidepath 
)
Sorry for the dumb question, but what is a “platform altitude”? Is that a UK term?
My answer to Christian’s question would be that when “cleared for the approach” he needs to maintain the last cleared altitude until on a charted leg of the approach, at which time the charted altitudes apply, unless instructed otherwise.
Also, is the ATC Surveillance Minimum Altitude Chart an MVA chart (or Radar Minimum Altitudes in Jepp terminology)? I assume that is what the 1500 and 1800 areas are. Correct?
Is it really true that ATC would vector to intercept the final track at 1500 or 1800 feet? My understanding is that vectoring should always intercept the final track at least 3nm outside the FAF. I don’t see any charted information indicating at what DME the cleared altitude (1500, 1800, whatever) would intercept the G/S and in any case it would be inside the FAF which is very unusual, especially given that the charted approach indicates 2000ft to G/S intercept at the FAF/D6.0.
Ibra wrote:
Southend: I could join at 1800ft on TAA to IAF+ILs
For me TAA applies only to GPS-based approaches. What is meant here? Also, if cleared to the IAF at 1800ft and then “cleared for the approach”, it would be necessary to climb from 1800ft to 2500ft to do the PT as charted. I’d query ATC on that clearance.
It looks like @CLE is training in Denmark. Perhaps someone can jump in with some help that uses either Danish charts or Jepp. I suspect that Christian has enough on his plate training for his CBIR without UK chart format adding to the mix at this point in time. Of course, when he plans to fly to the UK he’ll need to study that format too.
Unlikely since ATC should (and normally does) vector you onto the localiser well before glide path intercept – I am sure there is some standard how much.
It means “do not descend yet, wait until you intercept the glide path and then follow it”.
The annoying “Thames Radar” approach (no pun intended) is that they get you to intercept the localiser at an altitude, and then give subsequent step down clearances to interim altitude down to the platform, and then give you the final approach clearance.
“Intercept the localiser, report established” … “Descend altitude 3,000”…“Descend altitude 2,000”… “Descend altitude 1,800” …. “Descend with the ILS, contact Biggin Tower….”. I have no idea why. Maybe they get paid by the word.
chflyer wrote:
Sorry for the dumb question, but what is a “platform altitude”? Is that a UK term?
I don’t think this is an official term – it is the altitude from which you start the final approach – think of diving off a platform into the water…
chflyer wrote:
Also, is the ATC Surveillance Minimum Altitude Chart an MVA chart (or Radar Minimum Altitudes in Jepp terminology)? I assume that is what the 1500 and 1800 areas are. Correct?
Yes. In theory you should cross-check the cleared altitude against this when on radar vectors rather than trust ATC (you get brownie points in IR exams for doing it…)
chflyer wrote:
Is it really true that ATC would vector to intercept the final track at 1500 or 1800 feet?
Unlikely. ATC will normally vector you onto the ILS at or above the “platform altitude”; but the radar vectoring might apply when going around, or of course if you are in trouble and all bets are off. Hence they chart what can be done, even if it is lower than what is required in practice.
At Southend specifically, when practicing approaches, they tend to climb you up to 2,000ft instead to 2,500 for subsequent approaches, IIRC.
chflyer wrote:
For me TAA applies only to GPS-based approaches. What is meant here?
I think he means MSA (minimum sector altitude), which is the equivalent to the TAA for approaches where you arrive overhead a central navaid.
Cobalt wrote:
I don’t think this is an official term – it is the altitude from which you start the final approach – think of diving off a platform into the water…
As you say it is not an official term so everyone can have his/her own interpretation… I would say that the “platform altitude” is the (last) altitude of the initial approach. E.g. on a traditional NDB approach, you typically have the initial approach as a racetrack over the beacon. When established inbound you start the descent on the intermediate approach and the final approach will start at the beacon. In that case the platform altitude would not be the altitude from which you start the final approach but rather the racetrack altitude.
chflyer wrote:
For me TAA applies only to GPS-based approaches. What is meant here?
I’ve seen TAAs on some traditional approaches where the initial approach is PBN-based.
Can you complete the procedure on the last ATC alt clearance? Maintain it.
That may place you outside the DOC of the ILS. If the last clearance was say 4000ft but the platform (the GS intercept) is charted at 2000ft, the 4000ft will place the GS intercept at 2x the distance. It will probably still work but…
but what is a “platform altitude”? Is that a UK term?
It is where the GS intercept is charted (for an ILS). 2000ft here (EGMC)
good question will try and find out
You may well be right but I have never heard of that rule before.
If you are vectored above the platform altitude, which is the GS capture at FAF on an ILS, the clearance is when established on the LOC descend with the glide path. However, if you are vectored at platform altitude you would be cleared ILS. The controller is expected to vector you below the GS so you capture from below within the DOC. False GS lobes exist above the GS which could lead to an unstable coupled approach. To ensure you are on the correct GS there is a published GS altitude DME distance check, displayed prominently on Jeppesen briefing strips. The GS check being a call out multi crew.
In rush hour traffic it is not unusual that you are vectored straight onto the GS or even above, which means the autopilot may fail to couple. In theory the vectors should be at a LOC intercept two miles before GS intercept to enable autopilot capture from below. I once experienced a false lobe autopilot capture at Augsburg where ATC had vectored well above platform altitude and miles from the FAF. DOC extends to around 18D on an ILS which can be over ten miles from the FAF.
Bournemouth has a low platform altitude of 1,500 feet, so the radar vector ILS tend to be at 2,000 feet with a ‘when established descend on the glide path’ clearance.
By definition you have to be vectored to FAF at platform altitude on a 2D non precision approach.
Not having flown IFR in the UK, I must say that that ILS plate into Southend is strange for someone used to the FAA charts. Absolutely no mention of the ILS frequency in any box on the plate, just as a tiny I-ND box on actual chart. You’d think this would be pretty essential information for an ILS approach. I’ve aslo never encountered an ILS identified in this way either. Is this how the ICAO charts are for the UK?
