Airline Pilot Central Forums

Airline Pilot Central Forums (https://www.airlinepilotforums.com/)
-   Technical (https://www.airlinepilotforums.com/technical/)
-   -   Flight Director Preferences (https://www.airlinepilotforums.com/technical/76710-flight-director-preferences.html)

bonesbrigade 09-04-2013 07:15 AM

Can someone explain the specifics of dual cue? One of the posts above spoke of it commanding a rate of turn....

Say you are on a 360 heading with the FD in heading mode. You turn the bug to 270, so obviously a left turn.

My understanding is that the vertical bar would just displace to the left until you came to a heading of 270, at which point it would center up... am I incorrect?

DirectTo 09-04-2013 07:23 AM

The vertical bar would displace to the left as you said...but as you rolled into a bank it would center back up, so when you reached say 25 degrees it will be centered. As you near your selected heading it will move to the right, causing you to lower the angle of bank to achieve a smooth rollout.

As far as I know, there is no standard bank angle it will shoot for beyond short turns, which would vary from airframe to airframe (and could possibly even be pilot selectable).

bonesbrigade 09-04-2013 08:23 AM


Originally Posted by DirectTo (Post 1476681)
The vertical bar would displace to the left as you said...but as you rolled into a bank it would center back up, so when you reached say 25 degrees it will be centered. As you near your selected heading it will move to the right, causing you to lower the angle of bank to achieve a smooth rollout.

As far as I know, there is no standard bank angle it will shoot for beyond short turns, which would vary from airframe to airframe (and could possibly even be pilot selectable).

AHHH I see now. Interesting. I thought it just deflected toward the direction of turn only, didn't realize it was centered when you achieved the commanded roll rate.

Is the horizontal pitch bar the same way?

mike734 09-04-2013 10:38 AM

The following applies to the B737 classic and NG. Another advantage of the dual cue is the ability of turning one off but still using the other. Specifically, I like to climb in CMD CWS mode. That's Command Control Wheel Steering mode. I get to that mode by deselecting VNAV. When I do the horizontal command bar disappears and you are left with a vertical steering bar. In this mode I control airspeed with pitch. This is a very useful mode in turbulent air, mountain wave etc. This mode results in a solid pitch attitude during climb. The -700 can be particularly pitch sensitive. One thing to note, in addition to deselecting VNAV you have to reselect N1 to assure constant max climb power otherwise the engines will maintain MCP speed.

A single cue FD does not have this capability.

bonesbrigade 09-04-2013 12:41 PM


Originally Posted by mike734 (Post 1476938)
The following applies to the B737 classic and NG. Another advantage of the dual cue is the ability of turning one off but still using the other. Specifically, I like to climb in CMD CWS mode. That's Command Control Wheel Steering mode. I get to that mode by deselecting VNAV. When I do the horizontal command bar disappears and you are left with a vertical steering bar. In this mode I control airspeed with pitch. This is a very useful mode in turbulent air, mountain wave etc. This mode results in a solid pitch attitude during climb. The -700 can be particularly pitch sensitive. One thing to note, in addition to deselecting VNAV you have to reselect N1 to assure constant max climb power otherwise the engines will maintain MCP speed.

A single cue FD does not have this capability.

CWS... I know the ERJ has that but the CRJ ifly doesn't... DOesn't that allow you to set a pitch or bank when you hit the cws button and then the FD holds it?

mike734 09-04-2013 01:31 PM


Originally Posted by bonesbrigade (Post 1477061)
CWS... I know the ERJ has that but the CRJ ifly doesn't... DOesn't that allow you to set a pitch or bank when you hit the cws button and then the FD holds it?

There's CWS CMD and just plain CWS modes. CWS mode is achieved by pushing the CWS button but that mode is not very useful as it does not provide altitude capture. The CWS CMD mode is achieved by deselecting a vertical or lateral mode. In either case the FD is removed and the autopilot stays on. Pitch and roll are set by the pilot with the control yoke and the autopilot holds them until changed.

galaxy flyer 09-04-2013 01:34 PM

Bones,

I'm pretty certain the CRJ has a sync button on the yoke, that's CWS by another name. If I'm wrong, sorry I just fly the 604/605 versions of ProLine 4 or 21.

GF

mike734 09-04-2013 03:08 PM


Originally Posted by galaxy flyer (Post 1477101)
Bones,

I'm pretty certain the CRJ has a sync button on the yoke, that's CWS by another name. If I'm wrong, sorry I just fly the 604/605 versions of ProLine 4 or 21.

GF

That sounds like cool feature.

bonesbrigade 09-05-2013 01:16 AM


Originally Posted by galaxy flyer (Post 1477101)
Bones,

I'm pretty certain the CRJ has a sync button on the yoke, that's CWS by another name. If I'm wrong, sorry I just fly the 604/605 versions of ProLine 4 or 21.

GF

SYNC just syncs the FD bars to your current VertSpeed or PTCH or IAS, whichever mode you happen to be in.

Did you have to get a separate type for the 604 apart from the CRJ?

galaxy flyer 09-05-2013 08:02 PM

While the SYNC does that, if the A/P is engaged, you can press and hold SYNC, fly the plane manually, release the button and A/P will take over from where you left it. AP will be in amber.

No, it's a different rating, CL60 vs. CL65, never flew the CRJ, just the various Bombardier business jets. 605 is a differences course from the 604, as is the Global Vision from the Global Express with Honeywell.

GF


All times are GMT -8. The time now is 08:27 PM.


Website Copyright © 2026 MH Sub I, LLC dba Internet Brands