Setting of Barometric-altimeter Bug and Radio-altimeter DH
The barometric-altimeter bug and of the radio-altimeter DH should be set in line with Airbus Industrie’ SOP’s or company’ SOPs.
RA DH 
Visual  MDA/DA of instrument  200 ft 
approach  Note 1 
or 
200 ft above 
airfield 
elevation 
Non-ILS  MDA  200 ft Note 1 
ILS CAT I  DA  200 ft 
No RA  Note 1 
ILS CAT I RA  DA  RA DH 
ILS CAT II  Note 2 
ILS CAT III With DH  DA Note 2  RA DH 
ILS CAT III  TDZ altitude  
With no DH 

Table 1
(Table based on use of QNH)

Note 1 :
The RA DH may be set (e.g., at 200 ft) only for
terrain awareness purposes. Using the RA DH
should be discussed in the approach briefing.

For all approaches - except CAT I with RA, CAT II and CAT III ILS approaches -the approach MINIMUM callout is based on the barometric-altimeter bug set at the MDA(H) or DA(H).

Altimeter Setting – Use of Radio Altimeter
Page 3

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    Flight Operations Support

ote 2 :
CAT III DA, or the CAT I DA in readiness for a
possible reversion to CAT I minimas.

Radio-altimeter Callouts
Radio-altimeter callouts can be either:
.  
Announced (verbalized) by the PNF or the Flight Engineer; or,

.  
Automatically generated by a synthesized voice.

Callouts should be tailored to the airline’ operating policy and to the type of approach. 
To enhance the flight crew’s terrain awareness, a callout “ Radio altimeter alive “, should be announced by the first crewmember observing the radio altimeter activation at 2500 ft height AGL.
The radio altimeter reading should then be included in the instrument scanning for the remainder of the approach.
Radio altimeter readings below obstacle clearance levels listed below, should alert the flight crew:
.  
Initial approach : 1000 ft AGL;

.  
Intermediate approach (or minimum radar vectoring altitude) : 500 ft AGL;

.  
Final approach (non-precision approaches with defined FAF) : 250 ft AGL.

Note : The radio altimeter indicates the aircraft current height above the ground (height AGL) and not the height above the airfield elevation.
Unless the airport features high close-in terrain, the radio-altimeter reading should reasonably agree with the height above airfield elevation (obtained by direct reading of the altimeter if using QFE or by computation if using QNH).
Low OAT Operation
In a standard atmosphere, the indicated altitude reflects the true altitude above the mean sea level (MSL) and therefore provides a reliable indication of terrain clearance.
                                                                                         Getting to Grips with                                              Approach-and-Landing Accidents Reduction

Whenever, the temperature deviates significantly from the standard temperature, the indicated altitude correspondingly deviates from the true altitude, as follows:
　
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