Minimum descent altitude

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Non-precision approach: MDA, MDH and MAPt

The minimum descent ( English altitude minimum descent , MDA or English minimum height descent , MDH) is the minimum flying height , which at one instrument approach without vertical guide ( English non-precision approach , NPA) must not be exceeded before the approach lights or runway clearly in sight and a safe landing are possible. MDA refers to the height above sea level and MDH the height above the airfield or the landing threshold , provided this is more than 2 m below that of the airfield.

Unlike the decision height (English altitude Decision must be a DA) go-around will not be initiated as soon as the aircraft fell to the minimum descent, but such a decision can, if desired, to the missed approach point (English point Missed approach , MAPt) be delayed. The pilot of a non-precision approach can thus descend to the minimum descent altitude and maintain this up to the missed approach point and only then make a decision about continuing or canceling the approach if the visibility conditions were not sufficient beforehand.

See also

Individual evidence

  1. ^ Heinrich Mensen: Planning, installation and operation of airfields . 1st edition. Springer Verlag, Berlin 2007, ISBN 978-3-540-68106-9 , pp. 474 .
  2. ^ Operation of Aircraft . Annex 6 to the Convention on International Civil Aviation . In: ICAO (Ed.): International Standards and Recommended Practices . 10th edition. Part II: International General Aviation - Airplanes, 2018, ISBN 978-92-9258-475-7 , pp. 1.1–6 (English, admin.ch [PDF; 861 kB ; accessed on May 2, 2020]).
  3. ^ Procedures for Air Navigation Services - Aircraft Operations . Doc 8168 OPS / 611 ("PANS OPS"). In: ICAO (Ed.): International Standards and Recommended Practices . 5th edition. Volume I: Flight Procedures, 2006, pp.  I-4-1–4, I-4–6-1 - I-4–6-4 (English, archive.org [PDF; 1.7 MB ]).