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GFC500- It's here!!!


81X

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10 minutes ago, Bob - S50 said:

Ya, but if you do that won't you lose the ILS signal from the GTN too so there won't be anything for the AP to fly?

#facepalm.  You’re right, and there’s no switching to #2. 

Edited by 81X
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A bit premature, but here are a couple numbers you might want to squirrel away since they are different than you will find in the AFMS.  This comes from a Garmin rep who responded to my question on Beechtalk.
 
At least for the J model (not sure about the K but I assume it is the same):
 
The AFMS says that if the AP is coupled and the speed drops below 80 KIAS you will get an Underspeed warning and the AP will pitch down to regain airspeed.  The actual number is going to be 69 KIAS.  So the slowest speed you can fly on final with the AP coupled will be 69 KIAS.  I plan to fly a bit faster than that to avoid unanticipated nose down pitch.
 
The AFMS also says that ESP (stability protection) will kick in if you have: climbed above 500 AGL, are still above 200 AGL, are hand flying (AP not engaged) and the speed drops below 75 KIAS.  If that happens the pitch servo will apply a pitch down force to regain airspeed.  The actual number will be 65 KIAS.  That means you'll need to keep your speed above 65 KIAS until under 200 AGL to avoid an unanticipated nose down pitch force.  Shouldn't be too much of a problem.  However, it could be.  If I am flying solo and landing with less than 35 gallons, I'd be shooting for a speed less than 65 KIAS on final.  I'll have to make sure I'm under 200 AGL (probably about 1/2 mile final) before I slow to my final speed.  So I'm going to start practicing using 70 KIAS on final until inside 1/2 mile and then slow to my final speed.
 
The other option will be to disable ESP prior to entering the pattern.  You will be able to do that with the G5.  Push the knob, rotate to select ESP, push to disable.  ESP will automatically return to enabled when power is cycled on the G5, so if you want it off you'll have to do that on every flight.
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On 3/28/2019 at 8:07 PM, aviatoreb said:

Huh - so its just buttons?

I would not be surprised - it's only about 1.5" deep.  I could live without the GFC500 controller and have all the features built into the G3X.  But the 'emergency' blue button for straight and level is something you can brief your passenger about.

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I know that the G500 pitch and bank information comes from the G5. I'm wondering though if it has outputs to drive the flight director display on an Aspen PFD and if it will accept lateral mode inputs from the Aspen PFD.

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  • 1 month later...

Looks like the 500 got officially approved on the J/K per the Garmin website!  

Still flawless performance after clocking in about 15 hours!  One other really cool feature worth noting is that when you are on alt hold and change the baro setting, the AP goes to the new accurate altitude. Pretty neat!

Edited by 81X
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I took a look at Garmin's website and it looks like they will be starting work on the Pre-J models within the next 12 months.  I am happy to hear this.  I originally thought they were stopping with just the J's and up.  I have been flying my C model for over 12 years without an autopilot, not even the PC wing leveler.  It has been fun shooting approaches to minimums without an autopilot after 4 hour IMC cross countries but it is time for me to cave and get something and it is nice to hear Garmin is working towards that.  Thanks for this pirep.

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If the G5 is the brains then how come I do not have flight director guidance.  Why do I need a GFC autopilot for that?  Dual certified G5's and a GTN should be enough info to give guidance.

Isn’t FD historically a function combined with an autopilot?


Tom
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19 minutes ago, Jim Peace said:

If the G5 is the brains then how come I do not have flight director guidance.  Why do I need a GFC autopilot for that?  Dual certified G5's and a GTN should be enough info to give guidance.

Although I was hoping for the same thing, I suspect it has a lot to do with needing the control panel to select the desired modes.  While they could have built in some logic to allow different modes under different conditions, history has taught us that the vast majority of people these days don't bother reading the manual.  Without a control panel, it would be up to the pilot to know what mode the FD was in based on the rules of logic.  And if the pilot didn't bother learning what those rules were, an FD could be leading the pilot some place different than they thought.

Now if you could install the control panel without any servos to save maybe $4000 in parts and even more in installation costs just to get a FD, that might work (and sell).

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How does the GFC500 work with holding altitude without a pitch trim servo? I was just browsing Lafayette Avionics web site and it’s about 20.5 AMU installed for the GFC500 with dual G5’s and the 3 AMU pitch trim option.

I’m a novice to many things aviation but could I just get a pitch trim autopilot? I feel capable enough to take the ship to altitude. The real PITA is keeping it AT a specific altitude from wandering. Is that what an STEC-30 is? Basically a pitch trim autopilot?


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1 hour ago, ArtVandelay said:


Isn’t FD historically a function combined with an autopilot?


Tom

perhaps on older classic equipment but on my dual installation I can select on my ADI an altitude in the top right hand corner.  The G5 knows my current altitude being that it is tied into my pitot static system.  So that is good for pitch.  As far as exceeding limits my POH numbers, Vx Vy Vne etc could be input with a simple software update.

As far as course it has my current heading from the flux capacitor so difference between the heading bug and current heading should give it enough for lateral commands and it also has GPSS steering built in so it should work for NAV functions as well......

There is certainly enough information going back and forth between the G5's and my GTN650 to provide FD info.

I think on experimental versions the FD is there,,,,someone correct me if I am wrong

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1 hour ago, tigers2007 said:

How does the GFC500 work with holding altitude without a pitch trim servo? I was just browsing Lafayette Avionics web site and it’s about 20.5 AMU installed for the GFC500 with dual G5’s and the 3 AMU pitch trim option.

I’m a novice to many things aviation but could I just get a pitch trim autopilot? I feel capable enough to take the ship to altitude. The real PITA is keeping it AT a specific altitude from wandering. Is that what an STEC-30 is? Basically a pitch trim autopilot?


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All you need is a pitch servo and roll servo for the GFC to fly the plane.  The pitch TRIM servo just allows for manual electric trim (activated by your thumb) and auto trim (as commanded by the autopilot).  Without the pitch TRIM servo, the system gives you a visual indication that trim is needed and in what direction.  You then spin the wheel to trim as required.

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53 minutes ago, Jim Peace said:

perhaps on older classic equipment but on my dual installation I can select on my ADI an altitude in the top right hand corner.  The G5 knows my current altitude being that it is tied into my pitot static system.  So that is good for pitch.  As far as exceeding limits my POH numbers, Vx Vy Vne etc could be input with a simple software update.

As far as course it has my current heading from the flux capacitor so difference between the heading bug and current heading should give it enough for lateral commands and it also has GPSS steering built in so it should work for NAV functions as well......

There is certainly enough information going back and forth between the G5's and my GTN650 to provide FD info.

I think on experimental versions the FD is there,,,,someone correct me if I am wrong

Yes, it would know your altitude, and it could even know when you want to change altitudes because your altitude bug would not match your current altitude.  But how would it know at what speed or rate you wanted to climb/descend?  Climb at Vx?  Vy? 115KIAS?  200 fpm?  500 fpm?  And which one do you want?  I plan to use IAS for climb until my rate drops to 500 fpm, then VS until my IAS drops to 100, then IAS for the rest of the climb.  How could I tell that to the flight director?  In the descent I'll usually use 500 fpm.  But I might need something different if I'm using VNAV.  How do it know?

As for the course, yes it could fly GPSS, but how would it know when you wanted to fly a heading instead?  Say, for example, ATC gave you a short vector for traffic and then returned you to your route?

How would it know that you wanted VNAV?

Part of the procedure for an ILS or LPV is, after you have intercepted the glidepath, you set the altitude bug to missed approach altitude.  Could they make that workable without an APP button activation followed by a glidepath intercept?  Sure.  But it would probably require different procedures than it does with the control panel.  Could they count on people taking the time to learn the in's and out's?  Hell no.  And it would require two different manuals.  Could they count on people reading the correct manual?  Hell no.

Now could they do it with just the control panel and not the servos?  Sure.  Get the flight director now and add servos as funds allow later.

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29 minutes ago, Bob - S50 said:

As for the course, yes it could fly GPSS, but how would it know when you wanted to fly a heading instead?  Say, for example, ATC gave you a short vector for traffic and then returned you to your route?

It would know that I wanted heading when I toggle off of GPSS and the heading bug becomes active.

There are a few bugs that would have to be worked out but it is totally doable with some software changes.  My Stec 30 with ALT hold works perfect.  I dont want to have to spend so many AMUs just to get a FD.  Big picture is I have not needed a FD in the 4 plus years of ownership,,,I guess I will not have one for a while.....

I have the new software on my GTN for VNAV....I cant even get that to work right for VNAV guidance during enroute.  I get a TOD point on my GTN screen but it comes and goes with no guidance on my G5.

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4 minutes ago, Jim Peace said:

It would know that I wanted heading when I toggle off of GPSS and the heading bug becomes active.

There are a few bugs that would have to be worked out but it is totally doable with some software changes.  My Stec 30 with ALT hold works perfect.  I dont want to have to spend so many AMUs just to get a FD.  Big picture is I have not needed a FD in the 4 plus years of ownership,,,I guess I will not have one for a while.....

I have the new software on my GTN for VNAV....I cant even get that to work right for VNAV guidance during enroute.  I get a TOD point on my GTN screen but it comes and goes with no guidance on my G5.

Based on that, I assume you have VNAV enabled in the GTN (since you see a TOD).  Have you checked the altitudes in the flight plan to ensure at least one of them is green (a constraint)?  And I assume you know the VNAV guidance is magenta (>) along a vertical scale just to the left of the altitude tape?  And I assume you've set the altitude bug to the constraint altitude or lower?

I'm guessing you need the control panel to tell the G5 that you want to use VNAV.

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All autopilots calculate commands to the servos based on modes selected and inputs from sensors. All a flight director does is display the same pitch and roll commands on the attitude indicator. The fact that Garmin chose to put most of the smarts in the G5 rather than the mode controller doesn’t change the basic functionality nor should it affect certification or Garmin’s pricing. 

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2 hours ago, tigers2007 said:

How does the GFC500 work with holding altitude without a pitch trim servo? I was just browsing Lafayette Avionics web site and it’s about 20.5 AMU installed for the GFC500 with dual G5’s and the 3 AMU pitch trim option.

I’m a novice to many things aviation but could I just get a pitch trim autopilot? I feel capable enough to take the ship to altitude. The real PITA is keeping it AT a specific altitude from wandering. Is that what an STEC-30 is? Basically a pitch trim autopilot?


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It will use the elevator servo alone to hold alt if it has no pitch trim servo, and display on the G5 to trim up or down to relieve pressure on the elevator servo.    If you (or an automatic pitch trim servo) don't relieve the elevator pressure on the pitch servo while it is holding alt, if you need to turn off the autopilot for some reason you'll get a sudden pitch change since the A/P will release control of the elevator.

 

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13 hours ago, gsxrpilot said:

Exactly what I'm thinking... and a better autopilot :ph34r:

 

13 hours ago, LANCECASPER said:

I bet it would be a lot less expensive to do the STEC 3100.

I just went on to the STEC website and the 3100 is not certified for Mooney aircraft yet according to their website.  It is apparently in the works but not yet certified.  However, according to the website the cost to change from an STEC 30 to a 3100 will probably be far less than changing out to a GFC500.

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For us Cebtury IIb owners seems like the GFC is the way to go.  Trutrack being limited to >700 AGL or whatever is a deal killer for me.  No other good option out there save keeping the CIIb and adding an alt hold at half the cost and 2/3 the labor of the GFC.  Any other options?

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