Just thought I'd add this vid, as I liked it, and it's associated.

 

Thanks again Ralph, and please feel free to do a CAT I vid tut, if you have the time spare :-)

 

http://www.youtube.com/watch?v=sRV7f7IKdr4&feature=youtube_gdata_player

Holy crap. That music. . .

It's normal to think of a Category I approach as a standard "200 and 1/2" straight-in ILS procedure.  While it's true that such an ILS is a Category I approach, so is an NDB approach with only circling minimums.  There are three major subsets of Category I: precision straight-in, non-precision  straight-in, non-precision circling.  Precision approaches are limited to straight in procedures with an electronic glideslope (ILS, PAR or MLS) and employ a decision height / altitude (DH/DA) below which you must be in visual meteorological conditions (VMC) consistent with the visibility minimums for the approach.  All other Category I approaches use the minimum descent altitude concept for continuing the approach under VMC.

Establishing Visibility Minimums by Wally Roberts (IFR Refresher, June 1995)

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An SA CAT I ILS is a CAT I approach with a DH as low as 150 feet Height Above Threshold (HATh) using radar altimeter (RA) minima and a visibility minimum as low as RVR 1400 at runways with reduced lighting, using a HUD to DH. Only those operators authorized for CAT II operations using aircraft operationally approved for CAT II operations and equipped with an operable CAT II or better HUD are eligible for this operation. Operators are approved for this operation by the appropriate Operations Specification (OpSpec)/Management Specification (MSpec) or Letter of Authorization (LOA). Single pilot operations are not permitted to use SA CAT I landing minimums.

FAA InFO: 12002
 

Edit:

The above defined CAT I Approaches and that SA CAT I is a CAT I approach.  Adding some more definitions (from FSIMS 8900.1 Vol. 4, Chap. 2).

 

Enjoy.

 

CAT II Runway Visual Range (RVR) 1000. FAA Order 8400.13 authorizes CAT II approaches with a DH as low as 100 feet and visibility minimums of RVR 1000 to runways which meet all CAT II equipment, performance, and lighting requirements. The operator must use either autoland or HUD approved to touchdown.

Special Authorization (SA) Category (CAT) I. FAA Order 8400.13 authorizes SA CAT I approaches to a radio altimeter (RA) DH as low as 150 feet and a visibility minimum as low as RVR 1400 to runways that do not have touchdown zone (TDZ) or runway centerline (RCL) lighting when the approach is flown using an aircraft with an approved CAT II or III HUD to DH.

SA CAT II. FAA Order 8400.13 authorizes CAT II approaches with a DH as low as 100 feet and visibility minimums of RVR 1200 at runways which do not meet all of the lighting requirements (Approach Lighting System with Sequenced Flashing Lights (ALSF)-2, TDZ, RCL lights) for standard CAT II. The operator must use either autoland or HUD approved to touchdown.

Standard CAT II Operations. CAT II operations are approach and landing operations conducted with a DH of less than 200 feet (60 meters) but not less than 100 feet (30 meters), and an RVR of not less than 1,200 feet (350 meters).

Category (CAT) III Operations. CAT III operations are separated into three subcategories: CAT IIIa, CAT IIIb, and CAT IIIc.

CAT IIIa Operations. CAT IIIa is an approach and landing operation with an Runway Visual Range (RVR) of not less than 700 feet (200 meters) without a decision height (DH), or with a DH of less than 100 feet (30 meters), or an alert height (AH), which is typically between 50 and 200 feet, depending on aircraft certification and operator preferences. Both fail passive (FP) and fail operational (FO) airborne equipment can be used in CAT IIIa operations.

CAT IIIb Operations. CAT IIIb is an approach and landing operation with an RVR of less than 700 feet (200 meters) but not less than 150 feet (50 meters) and a DH of 50 feet (15 meters) or less, or an AH, which is typically between 50 and 200 feet, depending on aircraft certification and operator preferences. Both FP and FO airborne equipment can be used for CAT IIIb operations. Presently, the lowest FAA-approved minimum for any CAT III operations is RVR 300 (75 meters) due to difficulties in accomplishing safe ground movement for both aircraft and ground safety services, such as Aircraft Rescue and Fire Fighting (ARFF).

CAT IIIc Operations. CAT IIIc is an approach and operation landing without a DH and without RVR limitations (zero-zero). CAT IIIc operations are currently not authorized.

Nice video! Thanks!

 

 

No, not all ILS's are CAT I. In fact, I think you'll find most ILS approaches are not CAT I approaches.

If you look at the DH values of your two ILS approach examples, you'll see the 'regular' ILS has the standard DH of 200' while the CAT I ILS has a DH of 150'. These are two great examples you have provided showing exactly why one is a CAT I and the other is not.

 

Hi Ralph,

 

Great video, I can tell you're a trainer

 

Regarding the statement about the ILS Cat I or no Category ILS, I have to admit I'm not aware of that. I certainly don't believe this to be the case under ICAO. Is that an FAA specific thing you're referring to? Under ICAO an ILS approach can only be CAT 1, CAT 2 or CAT 3 (and subtypes of CAT 3). The system minima for CAT 1 is 200' DH. There is provision in EU-OPS for Cat 1 LTS (Lower Than Standard) minima of 150' DH, but that is predicated on an HGS (Heads Up Guidance System) and undoubtedly other formalities. There is also a normal CAT 1 (200' DH) with reduced visibility requirements, but that is predicated on EVS (Enhanced Vision System - like FEDEX have on their MD11s).

 

With regard to CAT III minima, our charts don't have that information, we have a section in OMC (Operations Manual Part C), that lists the takeoff and landing minima for all runways that we operate from which is primary document for LVO (Low Visibility Operations) and overrides whatever is on the chart (unless affected by NOTAM).

>Is that an FAA specific thing you're referring to?

 

I went to Jeppesen to get that information since they are responsible for replicating the technical aspects of the ILS approach plates. Their Advanced Navigation technical support rep Tony Peterson told me that:

 

"All ILS approaches are not CAT I, II & III.  Sometimes a runway may not have the infrastructure to support more than a CAT I ILS."

 

 

"All ILS approaches are not CAT I, II & III.  Sometimes a runway may not have the infrastructure to support more than a CAT I ILS."

Ah yeah, absolutely. Some airfields simply don't have the terrain or infrastructure for an LVO environment, meaning they can only support Cat 1. Others can support Cat 2 but not 3. Some 3A but not 3B. Understood. But you were saying that Cat 1 has a lower minima than an uncategorised ILS, I'm just saying that I have never heard of an uncategorised ILS is all

>Is that an FAA specific thing you're referring to?

 

I went to Jeppesen to get that information since they are responsible for replicating the technical aspects of the ILS approach plates. Their Advanced Navigation technical support rep Tony Peterson told me that:

 

"All ILS approaches are not CAT I, II & III.  Sometimes a runway may not have the infrastructure to support more than a CAT I ILS."

 

 

Ah yeah, absolutely. Some airfields simply don't have the terrain or infrastructure for an LVO environment, meaning they can only support Cat 1. Others can support Cat 2 but not 3. Some 3A but not 3B. Understood. But you were saying that Cat 1 has a lower minima than an uncategorised ILS, I'm just saying that I have never heard of an uncategorised ILS is all

 

I think we have a misunderstanding of a quote here...

 

Again, every single ILS is categorized as CAT I, CAT II, or CAT III.  What the guy was saying is that - unlike how it is in Flight Sim (where everything is essentially CAT III-capable) - real world equippage may only be able to be certified as CAT I.  That's why he ended with "ometimes a runway may not have the infrastructure to support more than a CAT I ILS."

 

There is no such thing as an "uncategorized ILS."  You'll only see CAT II or CAT III listed because CAT I is implied by the simple fact that it's an ILS approach.

 

 

There is no such thing as an "uncategorized ILS."

 

Thank you.

 

That's what I wanted to know.