Flight Crew Guide

cockpit reference codex

Search our Database


Precision approach – Category III operations

Wikis > Inflight > Precision approach – Category III operations
Precision approach – Category III operations

1. General
Category III operations are subdivided as follows:
(i) Category III A operations. A precision instrument approach and landing using ILS or MLS with:
(A) A decision height lower than 100 ft; and
(B) A runway visual range not less than 200 m.
(ii) Category III B operations. A precision instrument approach and landing using ILS or MLS with:
(A) A decision height lower than 50 ft, or no decision height; and
(B) A runway visual range lower than 200 m but not less than 75 m.
Note: Where the decision height (DH) and runway visual range (RVR) do not fall within the same category, the RVR will deter- mine in which category the operation is to be considered.

2. Decision height
For operations in which a decision height is used, an operator must ensure that the decision height is not lower than:
(i) The minimum decision height specified in the AFM, if stated;
(ii) The minimum height to which the precision approach aid can be used without the required visual reference; or
(iii) The decision height to which the flight crew is authorised to operate.

3. No decision height operations
Operations with no decision height may only be conducted if:
(i) The operation with no decision height is authorised in the AFM;
(ii) The approach aid and the aerodrome facilities can support operations with no decision height; and
(iii) The operator has an approval for CAT III operations with no decision height.
Note: In the case of a CAT III runway it may be assumed that operations with no decision height can be supported unless specifically restricted as published in the AIP or NOTAM.

4. Visual reference
(i) For Category IIIA operations, and for category IIIB operations with fail-passive flight control systems, a pilot may not continue an approach below the decision height determined in accordance with subparagraph (e)2. above unless a visual reference containing a segment of at least three consecutive lights being the centreline of the approach lights, or touchdown zone lights, or runway centre line lights, or runway edge lights, or a combination of these is attained and can be maintained.
(ii) For Category IIIB operations with fail-operational flight control systems using a decision height, a pilot may not continue an approach below the Decision Height, determined in accordance with subparagraph (e)2. above, unless a visual reference containing at least one centreline light is attained and can be maintained.
(iii) For Category III operations with no decision height there is no requirement for visual contact with the runway prior to touchdown.

5. Required RVR
The lowest minima to be used by an operator for Category III operations are:

Table 7
RVR for Cat III approach v. DH and roll-out control/guidance system

Category III minima

Approach Category Decision height (ft)
(Note 2)
Roll-out control/
guidance system
RVR (m)
III A Less than 100 ft Not required 200 m
III B Less than 100 ft Fail-passive 150 m
(Note 1)
III B Less than 50 ft Fail-passive 125 m
III B Less than 50 ft
or no decision height
Fail-operational 75m

Note 1: For aeroplanes certificated in accordance with CS-AWO on all weather operations 321(b)(3).
Note 2: Flight control system redundancy is determined under CS-AWO on all weather operations by the minimum certificated decision height.

Source: EU-OPS

See also:
Fail-Operational flight control system
Fail-Passive flight control system
Precision approach – Category I operations
Precision approach – Category II operations
Precision approach – Category III operations

The presented material is for training purpose only!
Web Hosting
Flight Crew Guide © All content, copyrights, trademarks and registered trademarks are the property of their respective owners. Web design 24web.eu