B747-400X MCP Question

[zachlog 18]

I have questions in two areas of the MCP:1. MCP/CMDOn the right side of main panel/MCP, there are 3 CMD switches for engaging the A/P (at least this is how I understand it). No problem engaging the A/P with the left-most CMD. What are the other two for ? HOW and WHEN/under what circumstances are they used/engaged ? They must be usable since the mouse cursor turns into a hadn when it's over these switches.2. BRTToward the right side of the main panel, there are two switches marked UPR and LWR respectively with BRT between them. Guessing they mean "upper" and "lower" respectively but for what ? What's their function and when are they used ?Thanks.

[downscc 1,327]

Normal operation is with A CMD engaged... all three are engaged for approaches.The BRT control varies the intensity of the displays. Real nice feature at night.

[zachlog 18]

Thanks Dan

[Qavion 19]

"Normal operation is with A CMD engaged... all three are engaged for approaches."Depending on the airline.Some airlines fly with C in CMD (I think UAL does/did). This gives each pilot an instant assessment of whether or not their autopilot (left = capt, right = F/O) is in agreement with the Centre A/P.Some airlines fly Left and Right A/P's, depending on who is actually flying... the Capt or F/O.Triple A/P's are automatically selected when you push the LOC or APP buttons for ILS approaches/autolands.Cheers.Q> Ян