Runway alignments for ILS landings

[ryanbatc 12,812]

So what determines the autoland capability of the aircraft?  Is that the aircraft itself and/or creq requirements?

 

And so category of ILS is only for tighter weather minimums?  They don't really teach us this stuff.  But I did read in that thread about ILS critical areas...  which I didn't even think about for this thread.  ..silly me.  If you were wanting to practice on a good weather day, it's likely we'll have some vehicle in the critical area, in which case I'd have to warn you :ILS critical area not protected.

 

What does that mean to pilots?  Does it mean they can't fly (or the A/P can't) autoland?

[FLEX1978 373]

Ok, aircraft type affects autoland capability, on the 744 you need 3 autopilots engaged for redundancy and have LAND3 displayed on the FMA. Unfortunately its been a while since I studied the 744, good excuse to get out the FCOM. Airbus requires CAT3 Dual on the FMA.

 

I have no idea how the ATC side of things work, CATIIIC is just no DH, I don't know of any operators that are certified for CATIIIC purely because you can't get of the runway due to zero visibility, CATIIIB is generally the highest.

 

I am pretty sure you also get roll out guidance on CATI don't quote me on that. Besides, if you are performing an autoland on a CATI ILS in CATI conditions you can see the runway so roll out guidance is not an issue.

 

If the computer screws up or the beam is affected you will be notified on the FMA and you go missed. This is why you require LAND 3 or CAT3 dual, the autopilots are monitoring each other constantly.

[g_precentralis 191]

you're saying we could just leave our CAT I ILS up and planes could fly it in bad weather to CAT II mins all day long?

Yes, and 1000 aircraft will land just fine and then 1001. aircraft may experience a problem. In other words it can be done, but its not safe.

[Great Ozzie 101]

 

So what determines the autoland capability of the aircraft? Is that the aircraft itself and/or creq requirements?

 

Boy oh boy... this is almost a 'chicken or the egg' thing...

 

The aircraft is going to HAVE to have some sort of Autoland certification... but then to have pilots not certified... This certification starts with CatII (not withstanding that SA Cat I category).

 

And so category of ILS is only for tighter weather minimums?

 

Exactly.

 

What does that mean to pilots?  Does it mean they can't fly (or the A/P can't) autoland?

 

Not sure what you mean here... normal instrument rating allows Cat I Wx mins (200 & and a Half... w/ exceptions).  

 

 

They don't really teach us this stuff.

 

Just pull up some different approach plates e.g. look at KDFW and look the differences for minimums for on of the runways (like 17C) between the 3 charts (CAT I / II / III). 

 

MKJP has a higher DA/DH due to the offset (much high viz requirement too in that case).

 

MKJP ILS RWY 12 (links to a pdf at this webpage: http://www.kingston.vatcar.org/cms/index.php?option=com_content&view=article&id=53&Itemid=84)

[Great Ozzie 101]

What does that mean to pilots? Does it mean they can't fly (or the A/P can't) autoland?

Ok... I think I know what you mean...

 

Yes you can fly... a current IFR rated GA pilot in his (legally equipped for IFR) Lancair Legacy could fly to an airport in zero/zero conditions. HOWEVER (the big but here)... you need 3 things to be legal to land...

 

When you go to make the landing... to descend below Cat I DH (legally) you must:

• Have the required flight visibility.
• The runway environment in sight (as listed in FAR 91.175c(3) )
• In a position to make a normal descent to landing

This is in general btw...

see FAR 91.175

 

==================

 

Back to the OT...

 

Want some confusing numbers regarding MKJP? Good... I thought y'all did...

 

The FSX map reports the ILS course as 121°... FSX sticks you on Rwy 12 on a heading of 119°. So a 2° offset.

 

ADE shows the ILS course as 115° and Rwy 12 as 112.1°. So a 3° offset...

 

My Navigraph for MKJP ILS Rwy 12... the ILS course is 120° and states the Approach Track is a 3° offset from the Rwy Heading (so 117°)... just like the Jepp.

 

Flying the PMDG 748 into MKJP... the PFD shows IMLY as 122° (Cycle 1210).

 

So how this all translates into FSX? We go back to the beginning... the ILS is offset (as stated on the charts) and not something you would want to do less than a CatI ILS approach into if trying to mimic RW ops.

 

Really kind of hard to blame FSX here for anything other than giving you a "normal" ILS offset approach.

[Boeing or not going 578]

Please read this and follow the instructions.

 

http://www.flaps2approach.com/journal/2013/1/16/magnetic-declination-fs9-fsx-navigation-datebase-update.html

 

The program is automated and has fixed all my alignment issues with FSX.

Thank you so much for this link! FSX just keeps getting better and better with all the mods out there.

[scott967 62]

Ok, aircraft type affects autoland capability, on the 744 you need 3 autopilots engaged for redundancy and have LAND3 displayed on the FMA. Unfortunately its been a while since I studied the 744, good excuse to get out the FCOM. Airbus requires CAT3 Dual on the FMA.

 

I have no idea how the ATC side of things work, CATIIIC is just no DH, I don't know of any operators that are certified for CATIIIC purely because you can't get of the runway due to zero visibility, CATIIIB is generally the highest.

 

I am pretty sure you also get roll out guidance on CATI don't quote me on that. Besides, if you are performing an autoland on a CATI ILS in CATI conditions you can see the runway so roll out guidance is not an issue.

 

If the computer screws up or the beam is affected you will be notified on the FMA and you go missed. This is why you require LAND 3 or CAT3 dual, the autopilots are monitoring each other constantly.

I guess my general question is that AFAIK, a CAT II/III localizer has things like dual xmitter in hot standby with auto-switchover, near field and far field monitors to verify signal, things like that.  With A/P engaged on a CAT 1 localizer, how does PF determine that the LOC signal is bad/gone at a critical time?  I'm assuming PF is head-down all the way?  Or is the monitoring pilot always ready for a visual takeover?

I suppose it's possible that a CAT III LOC could also flake out at a critical point of the approach even with the additional features, so you always are ready for that possibility.

 

scott s.

.

[ryanbatc 12,812]

Thanks for the responses guys. Learned some pilot things I didn't know.

[FLEX1978 373]

I guess my general question is that AFAIK, a CAT II/III localizer has things like dual xmitter in hot standby with auto-switchover, near field and far field monitors to verify signal, things like that. With A/P engaged on a CAT 1 localizer, how does PF determine that the LOC signal is bad/gone at a critical time? I'm assuming PF is head-down all the way? Or is the monitoring pilot always ready for a visual takeover?

I suppose it's possible that a CAT III LOC could also flake out at a critical point of the approach even with the additional features, so you always are ready for that possibility.

 

scott s.

.

With Boeing, if you lose the ILS signal below 200ft whilst in LAND3 the aircraft will still autoland. On the bus if you lose the signal you will get various indications on the PFD and glare shield indicating that the aircraft will no longer land. As you mention anything can go wrong and you should always be ready to go around.

 

PNF is a combination of monitoring and checking for any visual cues.

 

Edit - just checked, on the A3xx if you lose the glide slope signal below 100ft the aircraft will still land using the initial reference system like Boeing