Flight Director Preferences
 

For thos of you who have flown using both types of flight directors, both single and dual cue, which do you prefer and why?

WHat are the pros and cons of each?

All of my professional flying has been with the widget shaped FD's of the CRJ, but I've ferried at P210 that had dual cue, although at the time I didn't know how to use it.

I would think that more would prefer the single cue because it provides bank information as well, rather than just a need to turn.

Flown both and much prefer the dual cue. I find it more accurate. But I know other guys who much prefer the single cue "V-bar". To each his own.

I've noticed it's more common to have it be selectable in glass cockpit corporate aircraft whereas airlines assign the mode you'll use (example, CommutAir uses the V-bar in their Dashes, but other operators use the dual cue, and it's non-selectable by the pilots).

I don't know that I've ever thought of bank being an issue with dual cue...I just roll until it lines up and hold it. No different than a V-bar.

Flight Director Preferences
 

I also prefer the dual cue and find it to be much more precise than the single cue. They provide the same information, just a different presentation. On the dual cue you simply put the airplane symbol where the roll and pitch cues meet.

I admittedly might favor it because it was he first flight director I used (on the jetstream 31). I used it again on the DC9 a few years later. When I have been able to select it, I always chose the dual cue over the single.

The airplane I am training in now has an entirely different flight director - two circles, one slightly larger than the other. The instructor says "make donuts". Don't really care for it on the PFD, but works ok in the HUD.

I was sort of a "traditionalist" for a long time and preferred the single cue but I got used to the dual cue and now I will generally use that. I do agree with you that I feel more comfortable with the single cue in specific situations such as check rides because it is somewhat easier for me to process the bank information. At the end of the day though, my default setting is dual cue.

Nice thing about dual is you can fix pitch or roll independently of the other. I.e., you can work on your heading with its steering bar and ignore the pitch bar for a while if you need to. With v-bars if you want to do the same thing you're kinda guessing if you have the right bank unless you pitch up/down to get into the v-bars.

Hey guys thanks for all of the replies... I can see how the dual cue would be more precise, but I agree that in certain situations the single cue would be easier to process with a high workload.

To each his own I suppose. Maybe after I use a dual cue in the future I'll prefer it better. I wonder if any CRJ operators have a dual cue?

Zap, sounds like you're flying an FBW product? Ejet?

The "donut" symbology sounds like a "flight path vector" type of FD, like the E170 /175/190 have

Yes. The new Globals also have FPV flight directors. Took a bit of time to get used to but more precise than the single cue. I'm not particularly a fan of FPV during single engine ops/V1 cuts.

Always enjoyed flying to the ladies legs myself "V" bars.

Flight Director Preferences
 

I prefer the dual cue, I suppose is also more precise

Flown both and prefer the dual cue for same reasons listed above.

I used to prefer the single cue, it is pretty simple to follow. Now I hate them.

Supposedly the biggest difference between the systems is in the roll axis. What I have been told is that with the single cue system it is commanding a bank angle. On the dual cue it is commanding a rate of turn.

Definitely prefer the dual cue. Once you get used to that system it is way superior.

One of the benefits of the dual cue is that it is easier "to fly through the Flight Director" to quote one instructor. Say for instance that you need to do a immediate deviation or something over and beyond what was originally planned. You can easily see your way through the FD to do what you have to. The single cue is a bit harder to do that with.

There are numerous different flight directors out there, one I saw once, was two yellow paddles that would move up and down. On the airplane symbol there were yellow circles on the ends of the wings. I guess the idea would be that you would place the circles on the paddles. Strange.

Flying nowadays is more the AP following the FD since most people have the AP on/off @ 200'.

It was funny on the Diesel 8 because you could run the FD separate from the AP, so you could have the AP doing one thing and the FD doing something completely different.

I like flying with the FD & AP off, sort of a get back to basics philosophy!

YMMV!

Dual cue looks nicer. It doesn't remind me of a video game.

FD Off... hand fly that raw data shi.......

I'm a big fan of whatever one is used on the airframe that's paying my bills.

I recall being informed that the reason dual cue was used initially was for four engined jets with pod mounted engines. Not commanding a bank at low altitude (CAT II and III) was considered a good idea. Not sure if that's true but it does make sense.

Put it in the pink.

Dual Cue...
 

I think the V-bars are easier but I like the dual cue. I was an instructor on the 757/767 for 9 years and if you fly them "precisely" they are amazingly accurate. Most people just don't work hard at keeping them exactly centered so they think they don't work well.

Once you've flown the "donut" on the HUD and the FPV-oriented display with SVS, going back to either single or dual cue is like needle, ball and airspeed.

GF

I definitely prefer duel cue

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?

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?

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?

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.

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.

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?

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

I think the dual cue is more accurate but the single is more intuitive...I've only flown one plane that had the dual cue and I use it whenever I feel like changing it up.

No crap? Wow I'm gonna have to try that tomorrow with the sync button!

I can tell you first hand that the SYNC Button DEFINITELY DOES NOT DO THAT!!!!!
So we are going into OKC. WIth a VERY senior captain.
Literally the conversation...
"Hey cap, this dude on the internet says that if you have the autopilot on and then hold the sync button, you can turn and pitch the plane and when you let go then the AP will hold it."

Capt: "Well you know we have to try it."

AP on, I receive a turning vector with a descent... Grab the SYNC button, bank the airplane, after 20deg heading change get the aileron flag, let go, and the plane snaps back to the bugged heading with a waggling motion.

Don't go try this at home kids, galaxy flyer is wrong!

He isn't wrong, that's how it works in his airplane and mine, it does not however work that way in the CRJ. The SYNC button in the RJ only SYNCs the flight director to current conditions when hand flying with the flight director.

Bones and his VERY Senior Captain,

Considering I explicitly stated (see above) that I have no CL 65 experience, but experience in the corporate versions with associated ProLine avionics, I would have expected a crew to read the appropriate sections in the FCOM for YOUR specific, if related, type before exploring new ideas with passengers.

One is afraid for the safety of future passengers riding airliners

GF

My apologies, I didn't mean to sound accusatory... I was just telling a humorous story.

The captain has been on the plane for 10 years, so when i told him what you'd said he definitely wanted to try it.
I know there is a few differences with the CL60 and 65.... just didn't imagine that the same button would do something so different.

Question though, when I tried it, the yoke was difficult to turn against the AP servos... when you do it, or when someone uses the CWS button, does the backdriven yoke become easier to turn?

And it wasn't a revenue flight, it was a ferry flight to MX base. And we aren't graced with BBD FCOMs... we have garbage CFMs that are woefully lacking IMHO.

Yes, the servos are released until the SYNC is released, then A/P takes over using servos again. I'm a bit surprised about that, too.

GF

That's how I remember it on the later King Airs.

Maybe you guys shouldn't be "trying" things you don't understand. There's a place where you can read all about it. RTFM.

Where are MY donuts???