Uncategorized ILS?

R

rfresh737

New Member
I was told my someone working at Jeppesen that not all ILS approaches meet CAT I criteria (and therefore obviously CAT II or III either). He said these ILS approaches are "Uncategorized" but I can't find any FAA documents that define or discuss uncategorized ILS approaches.

So, I thought this might be a good place to ask if anyone knows of an uncategorized ILS approach somewhere in the US? I'd like to see what the approach plate looks like.

Thanks...
 
Autothrust Blue said:
The ILS Runway 25 to Oxnard, California doesn't say "Category Anything." Its minimums are 294' (250' ATDZE) and 1 mile. Here, have a look - http://155.178.201.160/d-tpp/1405/00674IL25.PDF

(Not a TERPS guru by any stretch of the imagination...)
Click to expand...

Well, yes, I can find a ton of ILS approaches that don't say anything about it being a CAT I or II or III. But in those cases, are those "uncategorized" or (now) "basic" ILS approaches?

Part of the category type confusion is that NOS ILS plates do not always mark a CAT I ILS approach as a CAT I. Jeppesen, for the airlines (United for example) marks EVERY CAT I or II or III ILS plate as such, so their pilots know for sure what kind of ILS approach it is.

I was hoping someone would have a reference to an FAA document discussing uncategorized/basic ILS approaches.
 
rfresh737 said:
Do you have a reference to that spec?

Thank you...
Click to expand...

Sounds like it has more to do with some variation of approach construction…sorta TERPy territory. This stuff can get complicated in a hurry requiring more than the typical jailhouse lawyer encounters.

Couldn't the guy at Jeps be more specific ?

Maybe it's in here someplace ?:

http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC120-29A.pdf

I didn't see it at a glance but maybe it's buried in there.

This from a typical Part 121 Ops Specs but isn't strictly related to approach construction/design per se, IIUC. More about legal approach authorizations:

Basic Turbojet Minimums

Basic turbojet minimums are defined as a precision or non-precision approach to
no less than RVR 4000 (1200 m) or 3/4 SM visibility, and a DH of no less than
200' or MDH of no less than 250'.

Then you qualify for the lower stuff by completing the airline's specific training programs.

This is another potential info source. Jim Terpstra wrote this series of articles many years ago. Jim retired a few years ago or you could email him and ask. He's a heckuva a nice guy. It goes beyond the Jeps Manual Intro section. Maybe it's in here:

http://craigmorton.com/ifr/

Wish I could be of more help.
 
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FAA AC120-29A has the following paragraph on page 4 which tells me that the FAA considers all ILS approaches to be one of the three: CAT I or II or III:

"For U.S. Operators, any instrument approach with a DA(H) or Minimum Descent Altitude (Height)
(MDA(H)) and visibility above that specified in OpSpecs for Category I, (see Appendix 7) is considered to be a
Category I operation (e.g., an approach with either a DA(H) or an MDA(H) which is not lower than 200 ft. HAT and
visibility not less than 1800 RVR is considered to be Category I, even though it may be based on a Navigational Aid
(NAVAID) other than ILS)."

I sent an email to Jim as well and am waiting for his comments on my question.

Thanks for the help everyone.

Ralph
 
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