16
$\begingroup$

In terms of aircraft equipment, approach minimums, procedural differences, and anything else relevant, how do the 3 types of a Cat III ILS differ from one another?

$\endgroup$
  • $\begingroup$ You may narrow your question as a simple search on wikipedia gives lots of information and great references to answer a significant part of your question. $\endgroup$ – Manu H Jul 10 '15 at 14:06
10
$\begingroup$

ICAO and FAA CAT III definitions

A CAT III operation is a precision approach at lower than CAT II minima. Sub-categories are listed below.

  • A category III A approach is a precision instrument approach and landing with no decision height or a decision height lower than 100ft (30m) and a runway visual range not less than 700ft (200m).

  • A category III B approach is a precision approach and landing with no decision height or a decision height lower than 50ft (15m) and a runway visual range less than 700ft (200m), but not less than 150ft (50m).

  • A category III C approach is a precision approach and landing with no decision height and no runway visual range limitation.

*I've omitted the JAA definitions.

Source Airbus Flight Operations Support documentation.


FAA Reference Material

The below links are to comprehensive FAA publications covering the areas as titled.

FAA AC120-29 for CAT I/II.

FAA AC120-28 for CAT III.

Thanks @Sports Racer for the comment with links to these documents.

$\endgroup$
0
$\begingroup$
  • Cat III A 600 feet (180 meters) Runway Visible Range (RVR)
  • CAT III B 150 feet (46 meters) RVR
  • CAT III C zero visibility

No decision height in any CAT III approach (CAT II is 100' and CAT I is 200')

$\endgroup$
  • $\begingroup$ A Cat IIIA approach can have a 50' DH for operators that need one. Not sure how wide or narrow that set of operators is, though. $\endgroup$ – Ralph J May 9 '15 at 17:15
  • 2
    $\begingroup$ Also please note that specifications differ here between FAA and ICAO. These figures are FAA-figures (which may very will be what the OP wanted) $\endgroup$ – Waked May 11 '15 at 8:18
  • $\begingroup$ Quite. So I don't appreciate the negative vote! $\endgroup$ – nimbusgb May 12 '15 at 8:23
  • $\begingroup$ You may consider editing the answer to a more readable format. $\endgroup$ – kevin Jul 23 '15 at 6:29
  • $\begingroup$ There's also the Alert Height, Read more in FAA AC120-28. faa.gov/documentLibrary/media/Advisory_Circular/120.28C.pdf $\endgroup$ – Sports Racer Sep 29 '15 at 21:08

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.