Ironflight

Ironflight

VAF Moderator / Line Boy
Mentor
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?.;)

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
 
GRT

Paul:

I find the HITS on the GRT to be much more intuitive than the bars on the ILS/GS needles. All this will be distilled down eventually into something a 20 hour student pilot can comprehend.

For an old fxxt like me, this is mind boggling! Just wishing the GRT HITS system (suppposedly 3 degree glideslope) didn't keep my wheels from chipping the paint off the church steeple a quarter mille from the touch down zone at my local airport.:rolleyes:

I fly at the top of the HITS box when I play with the system.

If I had to bet my life on getting my wheels on the runway with the GRT, I think it could be done. HOWEVER! I will never bet my life on it. At 68 years old, there.s too many bucket list items left to check off!:D
 
FD/HITS ILS look and feel

Paul,

Sounds like a really nice FD presentation. Couple Qs on the combo of FD/HITS presentations during an ILS:

When you flew that ILS, did tucking the aircraft symbol into the V-bars put (or move) the Flight Path Marker into the middle of the HITS boxes?

As the approach progressed, was it an intuitive feel, and did it feel like both displays were telling you the same thing?

Also just wondering, did you find yourself flying the V-bars and cross-referencing the FPM, or vice-versa?

I don't have HITS, but fly what sounds like a very similar FD at work, and this sounds like a very powerful combo. Thanks for the PIREP...very interesting stuff!

Cheers,
Bob
 
Bob - good questions! Since the V-bars are really an attitude command system, and the HITS is showing you positional data, it is more correct to say that if you have the aircraft tucked in to the V-bar, then you HEADING towards a centered HITS. Once you get there, then they will coincide. The hing about the HITS is that you know exactly how far off you are from the center of the corridor, but with the V-bars, you just know you are heading in the right direction. If you are following a course with the V-bars, and then punch in a new course 90 (or more) degrees off, you will get a turn command, but not really know how much farther you have to go once you are tucked in. With the HITS, positional error is much more intuitive.

In other words, the Flight Director is saying "Trust me, I'll get you there", while the HITS is showing you whee it's taking you. I guess the HITS is more comfortable for me because of that difference. The Flight Director is an excellent source of "follow me" guidance, and sometimes when I get thrown into a new simulator, I find myself following the FD without question because I am behind the airplane, and it is the easiest way to stay on target (with standard cockpit equipment).

In the limited testing I have done so far, i find myself following the V-Bars when I am testing the FD, but really keeping track of the FPM because I know what it is telling me.

Yes, having both of them available is pretty cool, and if you like one so much you don't want the other....then you can turn either of them off!

Mannan - I know what you mean about the HITS not necessarily giving you protected airspace - I agree, which is why I only fly the HITS on a real ILS, and use it as reference only for non-precision approaches.

Paul
 
Hummmmmm,

1st of all I need to finish wiring....

2nd of all is to have some fun......

Can't wait to see the up grades especially AOA.....
 
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best of both worlds

Paul, it sounds like the GRT has the best of both worlds. I too fly a FD in my C-425. I usually set the V Bars at 10^ up for takeoff and pitch to that at rotation. For flying around in the soup on assigned headings w/o AP on, it is great as well. I have only seen the HITS on a GRT for real, once and I loved it for an approach. Just ordered my finish kit today, so I don't have to make a decision on what to put in the panel just yet, but with reports like yours, my job will be easier. Keep up the good work.
 
FD + HITS

Maybe it is obvious to everyone but me, :eek: but I have always thought that both the FD and the HITS displayed together would be the perfect EFIS for IFR approaches. The only one I've found that has done this (until now!) was the Garmin G900. It seems that using the HITS boxes for general alignment with the FD for precision would make approaches a no-brainer.
Mark
 
Ironflight said:
snip...Since the V-bars are really an attitude command system, and the HITS is showing you positional data, it is more correct to say that if you have the aircraft tucked in to the V-bar, then you HEADING towards a centered HITS. Once you get there, then they will coincide. The thing about the HITS is that you know exactly how far off you are from the center of the corridor, but with the V-bars, you just know you are heading in the right direction...snip

snip...In other words, the Flight Director is saying "Trust me, I'll get you there", while the HITS is showing you whee it's taking you...snip

snip...The Flight Director is an excellent source of "follow me" guidance...snip

In the limited testing I have done so far, i find myself following the V-Bars when I am testing the FD, but really keeping track of the FPM because I know what it is telling me.

Yes, having both of them available is pretty cool...snip
Paul
Click to expand...

Paul,

Thanks, really makes sense (and hope I didn't over-snip the quote!). That really sounds like the cat's meow. "Follow-me", plus rapid feedback on results...somewhat instant gratification...a good thing when you're flying an approach to mins! :)

Put it all on top of Synthetic Vision and a moving map with weather, and what a great Situational Awareness tool you have indeed!

Purty neat!!

Cheers,
Bob
 
All the Bells and Whistles! (Video)

Several people asked for pictures of the new Flight Director, and others asked how it looks in combination with the HITS, so this morning I went out and flew the ILS into Brazoria County Airport (KLBX) with ?All the Bells and Whistles? enabled. That meant arming the Synthetic Approach for the HITS, tuning in the ILS, enabling the Flight Director, and making sure that Synthetic Vision was turned on (although the terrain is so flat, you really can?t tell?). In addition to all these features, ?recording? was also enabled, as was AOA (although you won?t see it because I never got that slow). The processor seemed to handle all of this with ease.

I joined up on the ILS from level fight at 1800?, a couple miles outside the FAF (FREEP).Following the Flight Director, I overshot the centerline a bit ? if I had just been flying HITS, I would have increased the bank angle without thinking about it to stay in the corridor. Once on the Localizer, and outside the FAF, I was holding altitude based on the 1800? I had set for the Flight Director ? once the glide slope was captured just outside FREEP, the Flight Director guided me down through the HITS. I stayed a little under the GS to keep a little space between the attitude chevron and the command bars so they wouldn?t merge in the low-resolution world of internet videos.

Another feature in the Beta test world is the addition of runways to the Synthetic Vision, and you can see how this looks as I come up on the airport ? tis should really help with height perception in the dark in terrain with more relief. You will also notice the ?height above touchdown that floats near the flight path indicator ? this is derived from GPS data, and keeps you from having to do math in public ? or on a dark and stormy night?.

Anyway ? here?s the video ? enjoy!

http://www.youtube.com/watch?v=Uu1Pqa1409Y

Paul
 
wonderful!

Great job Paul! Really nice to see the approach with all the bells and whistles. Good job of flying and narrating. Did you say GRT added you to their sales force??? :D Do you know if they are going to put the FD feature into the Sport?
 
Nice video. Looks like they still have some work to do - the video shows the FD commanding an overshoot of final!

:D

Still, this is a great advance. Hope the other vendors follow suit soon.
 
GREAT!!!

Hi paul, another great video. I always watch them about a dozen times and I usually see something different and interesting on every viewing.

On about the sixth viewing I noticed something interesting. On a normal steam guage CDI with glideslope you would expect that as you approach the top of descent point on an ILS the glideslope command bar (needle) would be at its upper most limit (because you are always intersecting the glideslope from below it) and that it would drift down to centre as you intersected the glideslope. That provides you with prior indication that you are in fact a) about to intersect the glideslope and b) are below the glideslope.

However I observed that the GRT glideslope command bar (yellow...on right) did not drift down as you would expect. In fact it did not appear at all until fully 7 seconds after you had left top of descent. If you were doing this approach using only that information it would be inadequate (ie without the HITS and FD). Do you think there is a software fault.

I noticed that this did not occur with the localizer command bar (needle) which appeared from the right hand side as the localizer was approached and moved to the centre as the localizer was intersected.

I would expect that for adequate situational awareness the "needles" should always appear at their extremity on a CDI as soon as a navigation signal is picked up. And they should stay there until intersection is imminent (within prescribed degrees) when they should then move to centre.

What do you think about that.
 
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So does a system like that with the new features added basically have the same functionality as a Chelton system except much cheaper?
 
Captain Avgas said:
On about the sixth viewing I noticed something interesting. On a normal steam guage CDI with glideslope you would expect that as you approach the top of descent point on an ILS the glideslope command bar (needle) would be at its upper most limit (because you are always intersecting the glideslope from below it) and that it would drift down to centre as you intersected the glideslope. That provides you with prior indication that you are in fact a) about to intersect the glideslope and b) are below the glideslope.

However I observed that the GRT glideslope command bar (yellow...on right) did not drift down as you would expect. In fact it did not appear at all until fully 7 seconds after you had left top of descent. If you were doing this approach using only that information it would be inadequate (ie without the HITS and FD). Do you think there is a software fault.
Click to expand...

Very observant Bob - I should have pointed that out - it is not the fault of the GRT - I am having a problem with my NAV antenna right now, and not getting the kind of signal strength I should have - what you were seeing was the fact that the receiver wasn't locking on to the Glideslope signal until that point. A fix is in work....it's been a slow degradtion, and is probably some contact corrosion somewhere...just haven't had the time to pull the wingtip off yet.

Paul

Paul
 
ILS or SAP

Paul,

Good video. You labeled it as an ILS approach but it was a synthetic approach in the video. Are you now able to get the HITS up with an ILS or still just with the SAP? Are there any other differences in what you see in the SAP vs. ILS? Were you hand flying this or using the autopilot?

The flight director looks good but there is so much guidance already showing that it seems to add more screen clutter. I like flying with the needles on my GRT which put them in the middle of the screen (assuming I'm flying them correctly) which seems easier to interpret than the flight director in that they are easy to see if you are banking, high, low, left or right of the desired flight path or approach guidance. I guess what I'm really asking is, how important is it to really have the flight director with what is already in the box? What am I missing in the importance of having this?
 
Capflyer said:
Paul,

Good video. You labeled it as an ILS approach but it was a synthetic approach in the video. Are you now able to get the HITS up with an ILS or still just with the SAP? Are there any other differences in what you see in the SAP vs. ILS? Were you hand flying this or using the autopilot?

The flight director looks good but there is so much guidance already showing that it seems to add more screen clutter. I like flying with the needles on my GRT which put them in the middle of the screen (assuming I'm flying them correctly) which seems easier to interpret than the flight director in that they are easy to see if you are banking, high, low, left or right of the desired flight path or approach guidance. I guess what I'm really asking is, how important is it to really have the flight director with what is already in the box? What am I missing in the importance of having this?
Click to expand...

The short answer to both your questions is that for this video, I had EVERYTHING going! ILS on the bars, SAP on the HITS, FD, etc - that was the point of the video.

In reality, the beauty of the GRT system is that just about every type of display and/or guidance is available for you to choose from - and you only turn on what you want/like. I personally am not as big a fan of Flight Directors as many - I strongly prefer HITS. I also like side bars better than needles. But that is basically because of what I grew up with (not the HITS of course - that is one new trick this old dog has learned!). The system is fully configurable in this regard - and you'll really have to enjoy clutter to turn it all on at once!

Paul
 
Great video, Paul. I'm trying to convince myself to not spend the extra money on the HX, but you are making it very difficult.
 
GRT beta

Paul that's incredible. What a great world we live in - at least the avionics part. Thanks for sharing. Bill
 
dhusk said:
Great video, Paul. I'm trying to convince myself to not spend the extra money on the HX, but you are making it very difficult.
Click to expand...


Darryl,

From what I heard, the Flight Director (along with the AOA) will be on the Sport, Horizon and Horizon HX. Of course, nothing is for certain until it is released.
 
Mike,

Yeah, I heard that, too. I wonder how the performance will be on the Sport and H1. I live in Michigan and we have about as much terrain as Texas, but I look forward to trips west and south that would take me over hills and mountains. It's only a "nice to have," but it sure looks neat. If the performance of the H1 or Sport with the whistles and bells is adequate, I can fly without the extra HX features. I plan on a 696, or the panel mounted equivalent, which will provide terrain warning.
 
Why do I want a GPS?

I agree this is pretty amazing stuff, and I have what might seem like a dumb question to some.

If I have a GRT with all these features why would I still want a separate GPS - eg Garmin 696? What will it give me that the GRT does not?

(I am not instrument rated, yet)
 
SMO said:
I agree this is pretty amazing stuff, and I have what might seem like a dumb question to some.

If I have a GRT with all these features why would I still want a separate GPS - eg Garmin 696? What will it give me that the GRT does not?

(I am not instrument rated, yet)
Click to expand...

Well, the first thing is that you need an IFR certified GPS to feed the GRT system - they do not have one as part of their package. Of course, the 696 doesn't qualify as IFR certified, so you need to find an appropriate panel mount.

Paul
 
Ironflight said:
I should have pointed that out - it is not the fault of the GRT - I am having a problem with my NAV antenna right now, and not getting the kind of signal strength I should have - what you were seeing was the fact that the receiver wasn't locking on to the Glideslope signal until that point.
Click to expand...

Aaaah I see Paul. Thank you for that information.

Your answer confirms that the "needles" (command bars) on the GRT are in fact driven by the NAV radio in your Garmin 430 during the relevant ILS approach you video recorded.

The question then remains as to whether the NAV radio can also provide guidance for the Flight Director and the HITS during an ILS approach. Or are the FD and HITS solely governed by the GRT "Synthetic Approach (SAP)" internal data base. In your video it seems apparent that the FD and HITS information is data base derived....but is there an option for it to be NAV signal derived.

If the FD and HITS are purely governed by a data base then how can we be assured that the ILS angle of approach in the data base is the same as that on the actual ILS glideslope. Of course most ILS glideslopes are set at 3 degrees, but due to terrain some can be at a higher angle.

If the FD and HITS are purely data base driven then is there some chance of a mismatch between them and the command bars (needles) on an ILS approach ?

If there was any possibility of that then it would obviously not be wise to "declutter" the screen by getting rid of the command bars (needles). They would always need to be the primary indicators.
 
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BrianNC said:
Any opinions on this?
Click to expand...

Well, to tell you the truth Brian, I have only flown behind a Chelton once, and I haven't compared features for so long that I simply don't have enough knowledge of that system to make a comparison. I guess someone would have to compare the systems feature for feature to see how they stack up. Maybe Stein has enough experience with both systems to compare them.

Paul
 
Captain Avgas said:
If the FD and HITS are purely governed by a data base then how can we be assured that the ILS angle of approach in the data base is the same as that on the actual ILS glide slope. Of course most ILS glideslopes are set at 3 degrees, but due to terrain some can be at a higher angle.
Click to expand...

Very good points Bob - while I don't have the time to go back and find the reference right now (perhaps GRT can chime in), when I select the Synthetic Approach and I have an ILS approach being "pumped in" from the GNS 430, I get a message "HiTS Display driven at ILS Glideslope Angle" (or something like that), so I believe that for an ILS, it is picking up the correct GS.

You are correct that if we could ASSURE ourselves that the HiTS is using the exact angle of the ILS glideslope, we could declutter the display a bit - personally, that is why I like having the side "bars" display (rather than the needles) because they are out of the way, but available for cross-checking. That's clearly a personal preference.

Paul
 
It would be unusal for the HITS to be driven by the ILS. I have the Chelton. and the HITS boxes are always GPS driven, it's simply a GPS overlay approach on the ILS. A CDI driven from the NAV is primary.
 
I guess I'll chime in since I just got done reading ALL of the new documentation that GRT put out today. The HITS is solely based on the synthetic approach which is only derived from the GRT database. It may have lateral alignment different from runway alignment if a localizer course is published for the runway selected in the database. I saw nothing in the "CURRENT" documentation to suggest that the HITS boxes are in any way tied to actual nav guidance from a radio nav aid. However, if we have equal lateral and vertical angular guidance, it will sure look like everything agrees with an ILS which is nice for situational awareness as long as you watch scales or something as a cross reference to the actual nav signal.
 
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Good reason to have a second 430/gi106a independent of the main gps and efis.

I'll let you know how close they match next week.....
 
Sticky1 said:
Good reason to have a second 430/gi106a independent of the main gps and efis.
Click to expand...

Why so? The GRT efis is still showing you actual radio nav lateral and vertical guidance with scales or needles if the radio is tuned, even in addition to all the other stuff that you may have turned on. Paul demonstrates a good mix of sometimes opposing philosophy; to have as many different backup guidance solutions engaged as you feel necessary or prudent for the circumstances, however, you have to be sure about every piece of what you're looking at when it really counts, otherwise turn it off or exclude it from the scan.
IE. Paul was certain that the ILS scales on the right and bottom were coming directly from the nav radio, plus he was visual, so he was having maximum fun load testing the processor.
 
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scard said:
The HITS is solely based on the synthetic approach which is only derived from the GRT database......... I saw nothing in the "CURRENT" documentation to suggest that the HITS boxes are in any way tied to actual nav guidance from a radio nav aid.
Click to expand...

I think this must be true and the proof is in the pudding (as they say) from viewing Paul's video. As Paul explained his glideslope antenna is not achieving good reception and this meant that he did not pick up the glideslope NAV signal until he was actually 7 seconds down the glideslope from top of descent. At that point the glideslope "command bar" suddenly appeared on the GRT EFIS.

However prior to that, the FD and HITS were providing solid glideslope information which would seem to confirm that the information is coming solely from a database.

I'm now wondering where the GRT ILS database information comes from and how reliable that database might be.

Upon viewing Paul's video yet again I also noticed that despite the fact that no NAV glideslope information was available for a period of time there was no warning signal. Of course on a conventional CDI there would be a red NAV warning flag to indicate that the GS reception was unreliable. I think I'd be a bit uncomfortable about that in a real world IMC scenario.

However the fact that we can constructively discuss these matters at all is solely due to the fact that Paul provided his excellent video in the first place.
 
Captain Avgas said:
Upon viewing Paul's video yet again I also noticed that despite the fact that no NAV glideslope information was available for a period of time there was no warning signal. Of course on a conventional CDI there would be a red NAV warning flag to indicate that the GS reception was unreliable. I think I'd be a bit uncomfortable about that in a real world IMC scenario.
Click to expand...

I agree that flags would be nice - much more noticeable than the "bars" simply goign away. I have flown other systems where the absence of the bars (or in mechanical devices, the bars being stowed out of site) is in itself the "warning" that there is no data - but flags are much more positive!

Paul
 
A crossfill function would be nice to transfer the flight plan to and from the garmins.

Anyway,

I finally had the plane out of the hanger and all the bells and whistles came alive.

Ok I am impressed. The 8.4 is crisp and clear. Detail is fantastic. The AHRS and Mag didn't need calibration. They are dead nuts on with the garmins.:D

This is going to be interesting comparing the 3 on the ils.
 
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