Cat iiib minima in USA

[RMC]

Long story but only have limited access to Jep plates prior to a sim duty (a series of IT failures)

The cat iii minima for KSEA is 300’ with no DH published.

Beer in the post if someone can check that the min8ma for cat iiia is 50’ and iiib is 0’ fail operational 787.

thanks in advance

[Check Airman]

Don't really understand your question. If you're familiar with the FAA format, the charts are here

https://www.airnav.com/airport/KSEA

[RMC]

Thanks for the link Checkairman (I am still having IT compatibility/ Jeps registration difficulties). My question was ....what is the cat iii RA DA (I assume 50’ cat iiia or 0’ cat iiib fail operational). The Jeps plates have a list of all airport CAT iii DAs. Seattle has notes that the ILS signal is prone to interruptions.

hanks for

[AerocatS2A]

Our minima are published in company documents rather than on the approach plates, should you be looking there instead? They are as you say, 50’ CAT IIIa and 0’ CAT IIIb, but it is a company document.

[aterpster]

Originally Posted by AerocatS2A

Our minima are published in company documents rather than on the approach plates, should you be looking there instead? They are as you say, 50’ CAT IIIa and 0’ CAT IIIb, but it is a company document.

As you correctly state, such restrictions or limitations are in the company's Ops Specs.

[FlightDetent]

Same here. The minima value would be the highest of

- airport installation possibilities
- aeroplane capabilities
- crew training
- AOC holder approval certificate
- local rules and state of destination restrictions

Only the first and the last would be in the AIP and thereafter in the Jepp / Lido / Navtech / insert a commercial provider of choice.

I am kind of envious, @RMC, that your company creates a table which is so conveniently located you thought it to be a Jeppesen original. Even if created by them it is your company data, called tailored pages. Pretty expensive too.

All the above being said, if can you check the first and last above without finding anything out of the ordinary, the standard (lowest permissible) numbers that you quote would apply (assuming you checked the boxes on the middle three).

[Intruder]

There is no DA for Cat III approaches, because you need not see the runway before landing. The Alert Height is per your OpSpecs and other company documents. Ours is 100', or the adjusted RA for 100' (due to the dropoff at the end of the runway) shown in the Cat II minima.

[Cough]

Originally Posted by Intruder

There is no DA for Cat III approaches, because you need not see the runway before landing. The Alert Height is per your OpSpecs and other company documents. Ours is 100', or the adjusted RA for 100' (due to the dropoff at the end of the runway) shown in the Cat II minima.

For Cat IIIA there very much is a visual reference requirement along with a DH (There is never a DA for CAT III approaches)

For Cat IIIB, there can be a DH along with a visual reference requirement (one light)... Depends normally upon the state you are operating to.

[RMC]

iPad issues now sorted!

As able to find this in our ops specs......but actually could not find anything in the 787 AFM which mentions the deviation due to KSEA 16L known glideslope issues.

[AerocatS2A]

None of our manuals, including Jeppesen approach plates, have any mention of glide slope issues at KSEA. Where are you seeing this?

Our CAT III minima are published in our B787 QRH, have you looked in yours?

[BleedingOn]

Concur with glideslope issues in Seattle. With protections in place come the real event though I would hope that signal interference would be less (if that’s what the problem is). Good luck with the sim!

[Intruder]

Originally Posted by Cough

For Cat IIIA there very much is a visual reference requirement along with a DH (There is never a DA for CAT III approaches)

For Cat IIIB, there can be a DH along with a visual reference requirement (one light)... Depends normally upon the state you are operating to.

Subject line asks about Cat IIIB in the US. No DH, no visual reference requirement - only the reported RVRs. From the 744 FCOM:

CAT III operations use an Alert Height (AH) based on radio altitude by selecting RADIO MINS on the EFIS control panel and setting 100’. Visual reference is not a requirement for continuation of the approach from the AH to touchdown.

[RMC]

Airfield brief

Aero - The 16L glideslope issues are highlighted in our airfield brief....have also experienced a loss of signal on 34R (due in both cases to crossing traffic). Only last a couple of seconds so aircraft goes into attitude stabilisation then ILS needs to be reselected. If it’s IMC though plan for an RNAV approach. Nope not in our QRH.....strange how the FAA ops spec alludes to it but the plates don’t!

[aterpster]

Originally Posted by Intruder

There is no DA for Cat III approaches, because you need not see the runway before landing. The Alert Height is per your OpSpecs and other company documents. Ours is 100', or the adjusted RA for 100' (due to the dropoff at the end of the runway) shown in the Cat II minima.

There are (or were) some limited airplanes that had a CAT III DA and a higher visibility. The last 10 727s we received were "advanced." They could auto-land but not decrab. DA of 50 feet and RVR of 1,000. It was pretty much useless.

[Mansfield]

There is no such thing as CAT IIIA or IIIB in US Op Specs. The only differentiation is fail passive or fail operational. If you have approval for fail passive only, the lowest possible minima are a 50' DH and RVRs of 600 TDZ, 400 MID and 300 R/O. If you have approval for a fail operational system, the lowest minima will be 300/300/300, with a company-specified alert height (can be as low as 50', but may be as high as 200'). However, the apllicable minima can NEVER be less than that published on the approach chart...which in the US means that almost all CAT III approaches will be limited to RVR 600 due to transmissometer capability. SEA, and several others, have runways with RVR 300 minima. In some cases the RVR may be limited to 700, although I don't know if any runways are still so constrained.

And there is not a chance in Hades that an ILS with signal interference problems will be approved for CAT III approaches.

[sleeve of wizard]

Originally Posted by AerocatS2A

None of our manuals, including Jeppesen approach plates, have any mention of glide slope issues at KSEA. Where are you seeing this?

Our CAT III minima are published in our B787 QRH, have you looked in yours?

AerocatS2A, that is an airline specific customisation of the QRH

[AerocatS2A]

Originally Posted by sleeve of wizard

AerocatS2A, that is an airline specific customisation of the QRH

Yes I know. But given that one airline has put that info in the QRH maybe the OP's airline has done something similar. I wasn't suggesting the information was definitely there, just that it might be.