View Full Version : 737 FD (selecting the master)
TotalBeginner
22nd Nov 2007, 17:38
How do you select your flight director as the master? Is it based on which FD switch is selected ON first?
What is the purpose of having a FD in "master". Is it to determine which course will be followed if selecting VOR LOC (Capt's or FO's)?
Kit d'Rection KG
22nd Nov 2007, 18:42
This needs to be in Spectators' Balcony. :ugh::cool::8
Correct
It indicates which respective Flight Control Computer (FCC) is controlling FD modes.
Pilot Flying normally has the Master.
jeff64
23rd Nov 2007, 09:18
and yes, the first FD selected ON is the Master.
TotalBeginner
23rd Nov 2007, 10:34
What about if the FO becomes the PF part the way through the flight. Do both Capt and FO have to select their FD's OFF and then back ON in the required order to change which is the master?
Does the master FD have anything to do with which A/P is in command?
Cough
23rd Nov 2007, 13:56
Master is related to the autopilot selected. e.g. Capt Master when A AP On.
When no autopilot selected, the master is the first one turned on. Has little significance though.
TotalBeginner
23rd Nov 2007, 14:32
Is there any kind of "safety feature" built in to this during the approach phase?
Do both CRS windows have to have the same value (when the ILS is tuned) to bring both A/P's online when APP is selected? Otherwise the A/P could be following the other guys FD which could be set to the wrong CRS or Freq (if you happened to miss that yours wasn't in master)?
Does that make any sense?
Kit d'Rection KG
23rd Nov 2007, 17:06
Has little significance though :eek:
No. :cool:
It has enormous significance. :eek:
Mode confusion is a convicted serial killer, and operating with the offside autopilot in the B737 has the potential to create massive and deadly confusion. :mad:
Human Factor
25th Nov 2007, 20:14
VOR/LOC mode (VOR or localiser tracking) follows the selected "Master" side. If a different VOR/ILS frequency is selected on the slave side, the slave lateral flight director will disappear. The vertical mode remains displayed.
On approach (dual channel, that is both autopilots engaged in approach mode), after a self test at about 1500' RA, both flight directors will indicate as "Master".
Not 100% sure about a different inbound course being selected? Never tried it (for obvious reasons I hope :\).
pipertommy
26th Nov 2007, 11:41
The slave testing-is this when the glide/localizer (PFD)start flashing when passing 1500RA.I am using a pc sim to practice on for the 737-300 TR and have wondered why they flashed:confused: