737ng Cat Ii

[Topper80]

Hi all, in section Limitation my FCOM report under Autopilot/flight director system:

The Minimum Use Height (MUH) for single channel autopilot operation is
defined as 158 feet AGL.

What about performing a single channel cat II with DH of 100 ft AGL?

The question is on the " last 58 ft......"

Thanks

[iflytb20]

That is strange. Our manual states
For single channel operations during approach, the auto pilot shall not remain engaged below 50 feet AGL

[nick14]

cat II is dual channel and hence the restriction doesn't apply as it is for single channel.

Nick

Sorry just read your post properly, early morning, ignor me.

[BOAC]

Normally Classic is 140ft, NG as ifly says is 50'.

Topper - can you expand on your clearance for CATII single channel?

[Topper80]

In according to FCTM and our AWO is possible to conduct CAT II approach single CH with manual land. The only limitation is RVR 350 instead of RVR 300 (CAT II with autoland)

In our Classic 737 we have only this limitation:
For single channel operation, the autopilot shall not be engaged below 50
feet AGL.

but in the NG:

For airplanes operated under FAA rules:
For single channel operation, the autopilot shall not be engaged below 50
feet AGL.

For airplanes operated under CAA rules:
The Minimum Use Height (MUH) for single channel autopilot operation is
defined as 158 feet AGL.

we are under CAA, so I have this problem......

[BOAC]

CATII man land - in my experience has not been permitted by the CAA on 737s. You appear to be allowed?

Classic - "the autopilot shall not be engaged below 50 feet AGL." - not seen that in my time. 150/140 yes

"For airplanes operated under FAA rules:
For single channel operation, the autopilot shall not be engaged below 50
feet AGL.

For airplanes operated under CAA rules:
The Minimum Use Height (MUH) for single channel autopilot operation is
defined as 158 feet AGL."

Is this the actual wording in your Ops Manual limitations section?

[Topper80]

All my posted data are current in my ops manual.... For this reason I opened this thread : what's in your manual ?

[rudderrudderrat]

CATII man land - in my experience has not been permitted by the CAA on 737s.
I can remember doing those in 1980s on 737 -200s, before the Auto Land was approved.

[BOAC]

Yes, rrat- me too, but the last company either did not bother or could not get approval for manland CATII from CAA Flt Ops despite my suggestion that a min RVR be placed on the event to overcome the CAA 'objection'.

Topper - I do not have a current OM, but am used to the FAA limits in CAA land. The only place I have so far come across the '158ft' was in a CAA ref in 2008 when Excel sought approval to introduce the 900, and I would assume that they would have had the limit changed to the Boeing approved figures. Any Excelers around to recall?

If the CAA do 'insist' on that figure then Flt Ops have been particularly somnolent in some areas and there will be some rapid OM revision.

Chris Brady's excellent 737 site quotes 50' for the NG Boeing 737 Limitations (http://www.b737.org.uk/limitations.htm#Autopilot/Flight_Director_System)
(and I see he also quotes 50' for the Classic)

[Topper80]

Do you know where I can find in Euops or CAA regulation about No performing CAT II manual land but mandatory autoland?

or new thread could be:

in the B737 is possible/allow perform CAT II approach with manual land?

[BOAC]

I suspect it is down to your company and your Ops Inspector from the CAA. I don't know where it will be written, if anywhere - it is probably a case of "if your Ops Manual says it is ok and the inspector has approved it, keep quiet":)

[Topper80]

For the B737 pilots: what is your company policy about CAT II approaches?

[Denti]

CAT II requires dual channel approach capability, but neither autoland nor auto-rollout capability. So manual landing from a CAT II approach is possible and allowed, however not really a heavy topic as the SOP suggests it should be an autoland anyway.

[BOAC]

No Denti - it does not, though it may be a company restriction of yours - from the Boeing NG FCTM:

"CAT II Operations
Category II approaches may be conducted using single or dual autopilots, or flight
director only, with two engines. For single autopilot operation, the autopilot must
be disengaged no lower than the minimum altitude listed in the Limitations
Chapter of the Operations Manual. Autothrottles should be disconnected when the
autopilot is disengaged"

The query is about A/P disengage height, not number of channels.

[Denti]

BOAC, that was a direct answer to Topper80 of course. Should be quite clear. As we are required to fly them dualchannel anyway there is no minimum use height during CAT II operation. That said the same is true for normal CAT I ILS as all ILS approaches until autopilot disconnect have to be flown dual channel. And yes, that is of course a company restriction.

[BOAC]

My apologies - I thought you had just stepped into the thread!

[Topper80]

You're right Denti, but in my FCOM limitation I have minimum use height for single channel 158 ft AGL. For sure I can bypass the problem performing a CA II in dual.... but in single channesl is allow disconnec the A/P at 158 and continue manual to the DH 100 ft ? :ugh:

I know... are only 58 ft....

[Whippersnapper]

I have operated the 737 for four operators, three British and one Irish. All have a minimum disengagement height of 158' from a coupled ILS approach. Autopilot used is not permitted below MDH for non-precision approaches.

This means an approach to Cat II minima would have to be done with both channels engaged. Manually landing from that would be foolish as the nose will have been significantly trimmed up at 380' radalt - manually flaring a severely out of trim aircraft in marginal visibility, especially on short, wet runways with any cross wind would be a handful and an unwarranted risk. It's manageable, but it's best to let the autoland do its job, so you fly the approach like a Cat III but use the Cat II limits - the airport would be in LVPs anyway.

[Topper80]

This experience is what I was looking for, thanks