Please assume the elevation of airport to 2000ft ASL. Under what conditions ATC might mandate aircrafts to fly at lower altitudes? What might be approximate speed at this distance?

  • 2
    $\begingroup$ Welcome to the site Gav. From the linked post: 3 miles per thousand feet is a standard glidepath. Please note that here it's one question per post, and for homework-like question it's better to include what you tried. $\endgroup$
    – user14897
    Nov 6, 2021 at 10:21
  • $\begingroup$ Is this information-gathering for a noise complaint? $\endgroup$
    – Arkhem
    Nov 6, 2021 at 14:17

1 Answer 1


Typical landing

Here is a typical landing at Paris CDG with a slope of about 3° (5%).

enter image description here

Jeppesen IFR approach plate, source

Runway altitude is 318ft.

  • You see the altitude is 3000ft from 10.2NM until a distance of 7.2NM.
  • Then it follows a radio glideslope at 3° (5%).
  • Speed entirely depends on aircraft performance. A large airliner may fly at 140kt (A320), but a small GA aircraft may fly at 70kt (Cessna 172).

Minimum altitude

In addition there are obstacles, and there is an indication on the plate: MSA 2000ft within D22.0 PGS. It means the minimum altitude which can be selected by a pilot within a circle of 22NM radius around PGS navaid (located at the airport) is 2000ft. Below this altitude there are obstacles outside of the approach path.

But as commented by @Bianfable, ATC may vector aircraft to speed up the landing, or to separate them. Vectoring means asking them to follow ATC indications instead of using a published procedure. This is not limited to landing aircraft.

In this case the aircraft may be instructed to fly at an altitude below the published one, but above the minimum radar altitude indicated on the first page of the documentation linked, in this case it's also 2000 ft until about the outer marker (OM) where it's 1500ft.

enter image description here

Jeppesen minimum radar alitudes, source

Note your question is difficult to answer as it cannot be assumed the landing is done in straight line, or the initial altitude is 3000ft (other approaches exist at this airport with a value of 4000ft as you'll see if your look at the linked documentation).

It will vary for a specific airport and direction of landing, and neighboring obstacles. A landing in a mountainous area might be different.

  • $\begingroup$ That's interesting. Does Jepp commonly publish the Minimum Radar Altitudes around an airport? In the US those are called Minimum Vectoring Altitudes and they are published by the FAA, but with very clear warnings that they are "to be used as a visual reference; they are not to be used as a navigational tool." (And as you mention they are very commonly lower than the published MSA.) $\endgroup$
    – randomhead
    Nov 6, 2021 at 16:18
  • $\begingroup$ @randomhead, that's not Jeppesen only, the information is published by the French AIP provider (SIA, a State agency), e.g. on their own package, page 35 $\endgroup$
    – mins
    Nov 6, 2021 at 18:06
  • $\begingroup$ @randomhead In europe the MVA charts are published and updated regularly with every AIRAC cycle. These charts however are only of an informative nature for pilots as they only refer to ATCOs work. This could be the reason why FAAs public versions are not for navigational use - the ATCOs most probably have the official AIRAC updated versions thereof to vector aircraft $\endgroup$
    – pcfreakxx
    Nov 6, 2021 at 21:13

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