A height above the runway based on the characteristics of the aircraft and its fail-operational landing system, above which a Category III approach would be discontinued and a missed approach initiated if a failure occurred in one of the redundant parts of the fail operational landing system, or in the relevant ground equipment. (ICAO – IS&RP Annex 6).
AC 120-28D
Hi,
I realised that there is no specific height,ie 200ft AGL mentioned on the subject of Alert Height. I believed most if not all the main airlines with such capabilities, they are using 200 ft AGL for the Alert Height. I also heard that there was a write-up of 100 ft AGL (Doc in 1991). Is there another review to increase it up to 200ft AGL?
Would appreciate your feedback.
Thanks,
joe
An Alert Height, as read from the radio altimeter, is a height defined for operational use above which a Category III approach would be discontinued and a missed approach initiated if a failure occurred in one of the required aircraft or ground systems.
The designated CAT III LAND 3 AH is generaly 100 feet RA on the 777