The guidance below is what is provided to US controllers in their manual. The approach gate is normally located one NM outside the FAF, which means that unless the weather is essentially VFR or a pilot request, the point of intercept is 3 NM outside the FAF. Note that the exceptions don’t apply to RNAV approaches which means that VTF is supposed to intercept the FAC at least 3 NM from the FAF. The reason for the difference is the avionics sequencing requirements for RNAV approaches.
5−9−1. VECTORS TO FINAL APPROACH COURSE
Except as provided in para 7−4−2, Vectors for Visual Approach, vector arriving aircraft to intercept the final approach course:
a. At least 2 miles outside the approach gate unless one of the following exists:
1. When the reported ceiling is at least 500 feet above the MVA/MIA and the visibility is at least 3 miles (report may be a PIREP if no weather is reported for the airport), aircraft may be vectored to intercept the final approach course closer than 2 miles outside the approach gate but no closer than the approach gate.
2.If specifically requested by the pilot, aircraft may be vectored to intercept the final approach course inside the approach gate but no closer than the final approach fix.
EXCEPTION. Conditions 1 and 2 above do not apply to RNAV aircraft being vectored for a GPS or RNAV approach.
b.For a precision approach, at an altitude not above the glideslope/glidepath or below the minimum glideslope intercept altitude specified on the approach procedure chart.
c.For a nonprecision approach, at an altitude which will allow descent in accordance with the published procedure.
Intercepting from above the ILS GS is not permitted by FAA guidance.
Intercepting from above the ILS GS is not permitted by FAA guidance.
Somebody ought to tell the controllers at IAD, JFK, MIA and BOS!
How do ATCOs determine the course they tell a pilot to intercept the localizer? I’ve been to a 2hrs shift with an ATCO at Langen, Germany, but he was working departure. Do they have a tool that calculates the vector or is it more like an educated guess?
How do ATCOs determine the course they tell a pilot to intercept the localizer? I’ve been to a 2hrs shift with an ATCO at Langen, Germany, but he was working departure. Do they have a tool that calculates the vector or is it more like an educated guess?
Experience. The radar shows the past and projected course over ground and the rest is a guess. The interception course doesn’t have to be exact. Frequently ATC ask the pilot for the present heading to get a feel for the wind vector.
I’m wondering, if I should help the ATCO so that I end up before the FAF (the approach gate mentioned above) by requesting a slightly different vector? My equipment shows me where I will intercept. ATCO and pilot are supposed to be a team so helping each other both ways might be appreciated.
Stephan, there are numerous reasons to vector you to a point inside the FAF. The most common ones are late requests by tower (e.g. to allow for departures), separation issues (e.g. having to vector through the LOC because the preceding traffic reduced unexpectedly) or simple screw ups. If I have to do this I will a) tell you and b) give you a lower altitude as soon as (if at all) possible, so that you can start your descend before reaching the LOC. If I can´t give you a lower altitude I would expect you to configure the aircraft accordingly in order to be able to catch the GS from above. If unable just tell me and you´ll get another lineup.
As for continous descend operations: We´ve been doing them for a number of years now, mostly vectored approaches, occasionally on the published procedure. Passing FL200 the given distance is still somewhat inaccurate, say plus minus 10 miles till touchdown, but coming down to FL70 it gets pretty good. Regular customers have become very good doing CDAs, with one sticking out doing it on almost every approach. On most of the approaches the aircraft are at GS altitude or slightly below when turning final, capturing it from above on final doesn´t happen too often.
Stephan,
your autopilot (DFC100) will capture the GS from above without a problem, just like my DFC90 (which is essentially the same)
your autopilot (DFC100) will capture the GS from above without a problem, just like my DFC90 (which is essentially the same)
Yes, I did check that via COPA to be sure.
Learning all the little bits and pieces out there is fun.
Somebody ought to tell the controllers at IAD, JFK, MIA and BOS!
It is policy, but unless you complain, the practice won’t stop being common. If you want to remain anonymous, use a NASA form to report it each time it occurs.
It is policy, but unless you complain, the practice won’t stop being common. If you want to remain anonymous, use a NASA form to report it each time it occurs.
My company monitors it and sends over management pilots for discussions with ATC every now and again.
