01. The Arrival Segment
With the theoretical knowledge in our backpack let’s see what this typical approach looks like in practice.
Arrival segment example
Refer to the included charts below. Assume you are coming from the SE from Boulogne along UA 2 for an approach to RW 28R. The arrival segment can normally be found on company entry charts. In this case, the arrival segment is Sandy-Biggin. You will find here the differences between theory and practice.
MOCA
The minimum altitude of 2300 ft is a company calculated MOCA as is indicated in the legend. Normally MEA is published on the app/arr/dep chart.
A MOCA will be calculated if no official MEA has been published in the AIP.
MEA
But what does MEA do for you? ICAO is very vague about it. All they say is that en route obstacle clearance is provided and that minimum reception altitudes and ATC requirements must be considered too.
Difference between MOCA and MEA
The area is normally a bit narrower than the MOCA area. In practice MEA over the same stretch can be higher (ATC requirements) or lower (narrower area) than the MOCA. A MEA will provide at least 1000 ft clearance above obstacles in an area of 5 NM wide along the track.
02. Initial and Intermediate Approach Segment
IAF and IF not always indicated on company charts
Refer to part of the Heathrow approach chart as depicted below.
Biggin should have been indicated as IAF. Not, however, in this case. The reason is that AIP charts do not always show IAF, IF, FAF, etc.
Company follows the official publication in this respect. An exception is made for FAF and MAPt. These will normally be published by company even if not depicted on AIP charts. The other fixes will only be indicated when officially published.
Chart publication and protected airspace
Operational limitations to remain within protected airspace as explained before remain applicable even though no IAFs or IFs appear.
Initial approach
Initial approach begins at Biggin and ends at Localizer intercept. IAF and IF are not indicated on the Chart. Still the operational limitations to stay in protected airspace remain valid. Moreover one of them – speed – is even more restrictive here: the maximum is 210 kt IAS instead of the standard 250.
Intermediate approach
Intermediate approach begins at Localizer intercept. Where it ends depends on whether you are looking at a precision or non-precision approach procedure.
This chart shows both, the ILS and the ILS no GP. The intermediate approach ends where the final begins. Final approach begins at GP intercept (precision approach) or FAF (non-precision approach).
Beginning of final approach
By coincidence FAF and GP intercept are located at the same position here. This does not necessarily have to be so.
03. Final and Missed Approach Segment
CAT I ILS final approach
CAT I ILS final approach ends at the DA of 280 ft.
ILS no GP final approach
ILS no GP final approach ends at the MAPt, which is fixed by the MM or 0.9 ILS/DME.
Be aware that non-precision final approach segment does not end when you reach the MDA of 460 ft but at the published MAPt.
MDA and MAPt
At the MDA you may decide to go around, but any required turns may only be initiated at the MAPt.
Obstruction wise level flight on the 460 ft. MDA to the MAPt is safe. The missed approach segment can be recognized as a broken line on the chart. Note that in the profile only the non-precision missed approach segment has been indicated.
Missed approach segment
The missed approach segment begins at DA or the published MAPt and ends at the Chiltern NDB.
Level acceleration
Level acceleration during the go-around manoeuvre is authorized from 1000 ft.
The normal case would have been a possible acceleration from the turn altitude of 2000 ft.
Minimum climb gradient
A minimum climb gradient of 150 ft/NM is thus required up to 1000 ft.