Last week I wrote about the Derived Angle of Attack indicator that Grand Rapids may be adding to a future release of their EFIS software. I have now flown quite a few approaches with it running and have yet to fool it in any way. (Mostly it is proving to me that I am flying my approaches much faster than I need to ? I should go out and fly some short field landings using the AOA, and will surprise myself at just how little runway it takes to put an RV on the ground!)
This last weekend I began playing with another new feature that they have written and are testing ? a Flight Director. I have flown several approaches with it, and yesterday I had it enabled for the long trip from Houston to Minneapolis ? it gave me something to play with while the hours and miles passed by. My first impressions are very positive ? it does just what a Flight Director should do; is smooth, responsive, and accurate; and its colors and representation are right up there with the best that I have used.
For those who haven?t flown with a Flight Director system, it is basically a display that shows you exactly what the autopilot is commanding the airplane to do. If the autopilot is engaged, then the actual airplane attitude should match the Flight Director commands. If the autopilot is not engaged (or you don?t have one), then the pilot?s job is to match the airplane attitude to the commands ? in effect, the pilot is nothing more than a ?meat servo? to do the job of the electro-mechanical servos. Most Flight Director?s include a set of command bars that look like an inverted ?V?. The attitude symbol representing the airplane is also shown as an inverted ?V?, but is a little smaller. You pull, push, or roll to nest the airplane?s symbol inside the command bars, and the plane is ?on guidance?. The GRT system is represented with purple command bars, and a yellowish attitude symbol ? both are well designed and very readable.
The Flight Director is enabled with a button push when selecting altitude or altitude rate. I have rarely used the altitude or rate pre-select because I have a simple AlTrak that doesn?t couple altitude to the EFIS, but now that I see that it can drive the Flight Director, this might very well change. You can command a vertical rate and it will provide pitch guidance to hold that rate ? of course with a complex autopilot, it will do that for you, but for a simple system, just match the bars and you get what you ask for. In addition to altitude and pitch commands, the Flight Director will give you bank commands to match guidance for enroute or approach functions. I have used it for both, and it is very precise. If I had a complex autopilot, I think I would like having this insight into what the EFIS is asking the autopilot to do ? it?s kind of a look inside the brains before things actually happen.
Now at this point, I must admit that I am sort of neutral on Flight Directors in general. To me, they are almost a generation old when it comes to giving the pilot useful information. Flight Directors tell you ?you should be here now? (in an attitude sense). You fly the airplane to that point, and chase the point around as it changes. You can be relatively sure that if you keep the airplane in the command bars that you will end up where you want to go (or where you have told the system that you want to go?). This is a vast improvement over flying raw ILS or VOR data that has to be interpreted in your head, but it is a step behind such display concepts as the Highway in the Sky (HITS) that shows you where you are in relation to a 3-D model of the surroundings or the ILS. While the Flight Director promises to get you to where you asked to go if you follow it exactly, the HITS gives you information to understand the multiple potential ways of getting to where you want to go. I have flown HITS displays enough that I am quite comfortable with what they are telling me, and feel that they give far better situational awareness. I know (and respect) pilots who have tried HITS and prefer a Flight Director. My experience has been that you need to fly the HITS a few times to really grasp it?s full capability, and once you do, the Flight Director will seem like looking at the world through a knot-hole. But this may be edging closer and closer to a Nose wheel/Tail dragger debate, and I don?t want to go there!
From the standpoint of Flight Directors, I am really excited by what I have seen so far in the upcoming GRT software. I know that several of the EFIS manufacturers are doing the same thing, and it never hurts to offer the option (unless it drags the overall systems performance down due to processor load ? not the case with the systems I have seen) for those that love to use it. I must admit, the display looks DANG cool set up for an ILS with the Flight Director and HITS enabled along with standard ILS bars along the edges, GPS-derived height-above ground, the AOA coming on?..in fact, if you?re the type that can suffer from information overload, you might want to turn a few of those things off to get started. We don?t want anyone?s brain to explode inside the outer marker?.![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I don?t know GRT?s plan for releasing the AOA and Flight Director software, but I know they tend to be conservative about letting stuff out into the wild until they are happy with it. I?m happy with that philosophy personally ? never promise what you aren?t ready to deliver!
Pictures to come when I get a chance?.
Paul
This last weekend I began playing with another new feature that they have written and are testing ? a Flight Director. I have flown several approaches with it, and yesterday I had it enabled for the long trip from Houston to Minneapolis ? it gave me something to play with while the hours and miles passed by. My first impressions are very positive ? it does just what a Flight Director should do; is smooth, responsive, and accurate; and its colors and representation are right up there with the best that I have used.
For those who haven?t flown with a Flight Director system, it is basically a display that shows you exactly what the autopilot is commanding the airplane to do. If the autopilot is engaged, then the actual airplane attitude should match the Flight Director commands. If the autopilot is not engaged (or you don?t have one), then the pilot?s job is to match the airplane attitude to the commands ? in effect, the pilot is nothing more than a ?meat servo? to do the job of the electro-mechanical servos. Most Flight Director?s include a set of command bars that look like an inverted ?V?. The attitude symbol representing the airplane is also shown as an inverted ?V?, but is a little smaller. You pull, push, or roll to nest the airplane?s symbol inside the command bars, and the plane is ?on guidance?. The GRT system is represented with purple command bars, and a yellowish attitude symbol ? both are well designed and very readable.
The Flight Director is enabled with a button push when selecting altitude or altitude rate. I have rarely used the altitude or rate pre-select because I have a simple AlTrak that doesn?t couple altitude to the EFIS, but now that I see that it can drive the Flight Director, this might very well change. You can command a vertical rate and it will provide pitch guidance to hold that rate ? of course with a complex autopilot, it will do that for you, but for a simple system, just match the bars and you get what you ask for. In addition to altitude and pitch commands, the Flight Director will give you bank commands to match guidance for enroute or approach functions. I have used it for both, and it is very precise. If I had a complex autopilot, I think I would like having this insight into what the EFIS is asking the autopilot to do ? it?s kind of a look inside the brains before things actually happen.
Now at this point, I must admit that I am sort of neutral on Flight Directors in general. To me, they are almost a generation old when it comes to giving the pilot useful information. Flight Directors tell you ?you should be here now? (in an attitude sense). You fly the airplane to that point, and chase the point around as it changes. You can be relatively sure that if you keep the airplane in the command bars that you will end up where you want to go (or where you have told the system that you want to go?). This is a vast improvement over flying raw ILS or VOR data that has to be interpreted in your head, but it is a step behind such display concepts as the Highway in the Sky (HITS) that shows you where you are in relation to a 3-D model of the surroundings or the ILS. While the Flight Director promises to get you to where you asked to go if you follow it exactly, the HITS gives you information to understand the multiple potential ways of getting to where you want to go. I have flown HITS displays enough that I am quite comfortable with what they are telling me, and feel that they give far better situational awareness. I know (and respect) pilots who have tried HITS and prefer a Flight Director. My experience has been that you need to fly the HITS a few times to really grasp it?s full capability, and once you do, the Flight Director will seem like looking at the world through a knot-hole. But this may be edging closer and closer to a Nose wheel/Tail dragger debate, and I don?t want to go there!
From the standpoint of Flight Directors, I am really excited by what I have seen so far in the upcoming GRT software. I know that several of the EFIS manufacturers are doing the same thing, and it never hurts to offer the option (unless it drags the overall systems performance down due to processor load ? not the case with the systems I have seen) for those that love to use it. I must admit, the display looks DANG cool set up for an ILS with the Flight Director and HITS enabled along with standard ILS bars along the edges, GPS-derived height-above ground, the AOA coming on?..in fact, if you?re the type that can suffer from information overload, you might want to turn a few of those things off to get started. We don?t want anyone?s brain to explode inside the outer marker?.
I don?t know GRT?s plan for releasing the AOA and Flight Director software, but I know they tend to be conservative about letting stuff out into the wild until they are happy with it. I?m happy with that philosophy personally ? never promise what you aren?t ready to deliver!
Pictures to come when I get a chance?.
Paul