kris
Posts: 38
Joined: Wed Mar 15, 2006 7:51 pm

MCP Course Settings...

Tue Jul 24, 2007 11:17 pm

Sorry if this is a dumb question... but why do airliners' MCP have independent course settings for the pilot and FO?

Thanks in advance

Kris
 
pilotaydin
Posts: 2099
Joined: Tue Sep 07, 2004 12:30 am

RE: MCP Course Settings...

Wed Jul 25, 2007 1:09 am

not a dumb question at all, here are some of the answers....

1. When doing an ILS, it is procedure to use both sides because both nav receivers are independent for captain and F/O, so we compare signals from left and right, when approaching an airport, so when one pilot makes a callout we confirm it by looking at our own instruments and making sure they are both showing the same....

2. CAT II/III when we do low visibility operations, we need both sides to be working as they are dual autopilot approaches....

3. In case one of our FCCs fail or nav receivers fail, we can cycle the flight director so the aircraft takes data from one side versus the other.

4. Non precision approaches, sometimes we do full approaches, so one side will be set on the inbound course, and the other side will be on the outbound course to complete the full approach.

hope this helps

ao
The only time there is too much fuel onboard, is when you're on fire!
 
kris
Posts: 38
Joined: Wed Mar 15, 2006 7:51 pm

RE: MCP Course Settings...

Wed Jul 25, 2007 6:16 am

Many thanks for the information, much appreciated.

Kris
 
SlamClick
Posts: 9576
Joined: Sun Nov 23, 2003 7:09 am

RE: MCP Course Settings...

Wed Jul 25, 2007 6:21 am

Also, in the absence of DME (it could happen!) you can very easily set a cross-bearing to fix an intersection.
Remember, it sets "course" not heading.
Happiness is not seeing another trite Ste. Maarten photo all week long.
 
David L
Posts: 8549
Joined: Tue May 18, 1999 2:26 am

RE: MCP Course Settings...

Thu Jul 26, 2007 3:54 am

Quoting Pilotaydin (Reply 1):
4. Non precision approaches, sometimes we do full approaches, so one side will be set on the inbound course, and the other side will be on the outbound course to complete the full approach.

Is it too simple to expect that the Captain's Course selector is linked to AP1 and the FO's to AP2 or is there a way to link either selector to the AP in use?
 
User avatar
Jetlagged
Posts: 2562
Joined: Sun Jan 23, 2005 3:00 pm

RE: MCP Course Settings...

Thu Jul 26, 2007 9:58 pm

Quoting David L (Reply 4):
Is it too simple to expect that the Captain's Course selector is linked to AP1 and the FO's to AP2 or is there a way to link either selector to the AP in use?

No, typically that is the case with non-glass cockpit aircraft. This is why on older aircraft like the 747 Classic it is normal for the Capt to use AP A and the F/O to use AP B.

Course selection can be transferred using the instrument switching system. This allows the crew to select the source of the information used. The 747 Classic had a course transfer switch on the AFCS mode control panel. This could be used to select both AP's used CRS 1, both used CRS 2 or the sources were split (default position). If ILS or LAND is selected the transfer switch auto-trips into the split (or MULTI) position, so the transfer was only intended for use in VOR navigation. In some 747 airline configs the course transfer switch also affected nav radio source transfers as well.

For modern glass cockpits with FMCs, course is either auto selected or manually selected via the FMC CDU, same information both sides. Aircraft like the 757/767 still have dedicated VHF nav tuning heads, but for ILS there is only one controller.
The glass isn't half empty, or half full, it's twice as big as it needs to be.
 
David L
Posts: 8549
Joined: Tue May 18, 1999 2:26 am

RE: MCP Course Settings...

Thu Jul 26, 2007 11:21 pm

Thanks, Jetlagged.

Quoting Jetlagged (Reply 5):
This is why on older aircraft like the 747 Classic it is normal for the Capt to use AP A and the F/O to use AP B.

Course selection can be transferred using the instrument switching system.

Thanks. So, in this example...

Quoting Pilotaydin (Reply 1):
4. Non precision approaches, sometimes we do full approaches, so one side will be set on the inbound course, and the other side will be on the outbound course to complete the full approach.

... you could change from inbound to outbound course either by switching APs or by switching which course setting the current AP is using?

Who is online

Users browsing this forum: RRTrent and 20 guests