Problems wit AeroCruze 100 install (lack thereof)

[cappy48]

The Gyro Set does not always need to be done, but sometimes it helps if the internal gyro is off. It’s possible someone accidentally got into Gyro Set for a second or two during install and that threw it off. Either way, it’s a simple fix and is a great auto pilot.

Jesse is correct.. a simple fix..

If you hold the knob in too long while engaging the AP, it can accidentally slip into "Gyro Set" mode.

To reset you have to have the plane VERY level and stationary, push and hold for 45 + seconds, and it its done.

The test is .. fly straight and level for 10 seconds, then push the EMERG LVL button, The plane should continue flying level if the gyros are set correctly.

FWIW. I have been able to "Gyro Set" in the air on a very calm day...

Cap

 

[cappy48]

Just to update from my previous post, B/K has finally started shipping the install kits. I have received one and another has shipped. Apparently there was a problem with FAA approval on their “harness packaging”, which appears to have been fixed. I would still take a TruTrak over a Trio by a long shot.

All true..

Also...

Many parts were made "in house" at TT.

This stopped at the when BK came in, and they were sourcing new parts suppliers when the 'Rona hit.. It has been a perfect storm.

Latest heard was late last week when back orders were being shipped.. Aviall… that's another matter...

The "long shot" Jesse may be referring to is partially the time consuming and difficult installation of the Trio, And several have been removed for various performance reasons...

Cap

 

[cappy48]

Functionally, yes. Legally, as I understand it, it's a bit muddier as that config was not certification tested. So, it depends on how the shop feels about it.

I believe that there's a bit of a quirk in the STCs where if you install the GFC first and then swap out the GNS for the 440 it's legal, but if you have the 440 installed first, technically the GFC cannot be installed as it violates the install manual.

Flying cheezehead is correct.

Ant it is getting muddier still . Some have found that the GFC will respond to "Min speed" setting by pushing the nose down when it is turned OFF. (!)

The "Correct" Garmin navigator will "inhibit" this action below 200 ft. GPS altitude. Other navigators will not. Lots of forum conversation about it. Some have reverted to using the breaker as an OFF/ON switch until this is sorted.

Its confusing so far..

Cap

 

[Chris Ellington]

cappy48,

Thanks for the offer, I'll probably shoot you an email and take you up on it. I actually called BK last week to ask a question about the STC availability since they purchased TT and they quickly answered phone and answered question, so customer service is about as good as I've found in this business. after watching some youtube videos and other reviews, I'd probably lean towards the TT system. I work in manufacturing and understand a lot of these supply issues are affecting everyone right now so I wouldn't single them out for having delivery delays.

Chris..

I have lots of pix of our TT install. Send me your e-mail addy to Dave@biztechind.biz We installed it ourselves (I got one of the first if not the first Vizion shipped the morning they got the STC letter from FAA)

We documented the install, and test flights.. Will send it all if you wish.

Cap

 

[cappy48]

cappy48,

Thanks for the offer, I'll probably shoot you an email and take you up on it. I actually called BK last week to ask a question about the STC availability since they purchased TT and they quickly answered phone and answered question, so customer service is about as good as I've found in this business. after watching some youtube videos and other reviews, I'd probably lean towards the TT system. I work in manufacturing and understand a lot of these supply issues are affecting everyone right now so I wouldn't single them out for having delivery delays.

No Problem..

It is a good Autopilot.

It fit our mission perfectly. It has limitations if you are flying hard IFR a lot, but for VR and occasional IFR it's a winner at the price point. And... on the Piper forum, we have figured out a way to have it legally "assist" with approaches..

Everybody is getting hit with supply issues..

Cap

 

[Cherokee Lover]

****HELP**** Wondering if I could get some intel here for problems I am having with my newly installed Aerocruze 100?

As stated in an earlier post...when I first tested it the thing was all over the place in roll. It would overshoot the magenta line in GPSS and come back & forth to it like it was searching. When I set it to TRK mode it made an immediate left hand steep turn...didn't hold the current TRK. When I first turned it on the ground it would make a full left hand turn. I performed a "Gyro set" and that seemed to fix it for the next 1 hour flight (Manual says this should only have to be done once).

One week later...I turned it on during pre-flight on the ground and it started its problems again. The control wheel made an immediate left hand turn. I did ANOTHER Gyro Set and flew it. It worked OK for about 20 minutes.

Then...while on a Mock LPV approach it overshot the lateral line (No turn anticipation) and lined back up. Just shortly after it coupled and descended it made a right hand turn and started heading in another direction like it had a mind of its own. After I broke off I leveled off and initiated TRK mode again. While in TRK it drifted way left and right. would NOT hold TRK worth a damn!

I downloaded all the manuals and verified the PA-28 settings on the controller AND the G430W settings. All settings were correct! I am thinking there has to be a software issue with the internal gyro???

Any suggestions??? Anybody else have these issues following installation???

 

[cappy48]

****HELP**** Wondering if I could get some intel here for problems I am having with my newly installed Aerocruze 100?

As stated in an earlier post...when I first tested it the thing was all over the place in roll. It would overshoot the magenta line in GPSS and come back & forth to it like it was searching. When I set it to TRK mode it made an immediate left hand steep turn...didn't hold the current TRK. When I first turned it on the ground it would make a full left hand turn. I performed a "Gyro set" and that seemed to fix it for the next 1 hour flight (Manual says this should only have to be done once).

One week later...I turned it on during pre-flight on the ground and it started its problems again. The control wheel made an immediate left hand turn. I did ANOTHER Gyro Set and flew it. It worked OK for about 20 minutes.

Then...while on a Mock LPV approach it overshot the lateral line (No turn anticipation) and lined back up. Just shortly after it coupled and descended it made a right hand turn and started heading in another direction like it had a mind of its own. After I broke off I leveled off and initiated TRK mode again. While in TRK it drifted way left and right. would NOT hold TRK worth a damn!

I downloaded all the manuals and verified the PA-28 settings on the controller AND the G430W settings. All settings were correct! I am thinking there has to be a software issue with the internal gyro???

Any suggestions??? Anybody else have these issues following installation???

OK... this is reach..

My WAG is a cold solder joint on or near the solid state gyro module on the Main circuit board. (In a previous life I was a electronics service technician, nothing to do with avionics)

Cap

 

[rtk11]

Not sure if this is helpful or not as I took this from the TruTrak Vizion installation manual that I received in 2019 (image below). Just wondering... all the settings on the TruTrak are confirmed? Baud rate set at 9600?

 

[Cherokee Lover]

Yes...the baud rate and all other recommended settings for a PA-28 are set in the controller per the install manual...and set on the G430.

I pretty much eliminated the G430 because it takes an un-commanded roll to the left as soon as I power it up on the ground...and turn the AP on. This happens before the GPS even has time to run up.

When I perform a gyro set it clears up...but the next day it does the same thing. i spoke with the BK rep and he was stumped as well.

 

[Cherokee Lover]

BK said they will send out a donor controller so they can take a look at mine. Just wondering if anybody else had a software issue with the controller upon install? There are no real issues being reported anywhere online that I can see.

 

[cappy48]

BK said they will send out a donor controller so they can take a look at mine. Just wondering if anybody else had a software issue with the controller upon install? There are no real issues being reported anywhere online that I can see.

I got the first one shipped and have been following the TT closely..

Among thousands of installations... (ya really! )

VERY few issues.. Some wonky control heads (rare) a few servos with issues, mostly installation issues (the third red wire in the harness and cable tensions not being set as per the manual. )

Software issues … In version #4 (first and only update so far.... new units since Jan 15 2020 are shipped with the new #4 version) the manual directed turn rate was increased, (now a rate one turn rate) the bug that prevented the static lag setting from being saved was squashed, and the TT now integrates with the Garmin G5 and Aspen E5.

Reliability has been very good. Most issues are at install (see above) very few reported issues after the systems have been in service for a while...

This info is not from warranty data or anything, just posts in the forums.. So it may be inaccurate..

FWIW!

Cap

 

[Cherokee Lover]

Appreciate the feedback Cap! Can I ask you another question?

Since I am new to an AP for approaches I do notice that when on the final LPV approach leg (& coupled) the nose of the plane appears to be making several shallow S-turns on its path to the runway. Some seem like 10-15 degrees. However, the CDI stays pretty centered (Lateral) and the glide scope stays just a tad high (Maybe 1/2 a deflection)...but on GS.

I am thinking that would be normal due to winds and/or thermals...but it seems to be easier/steadier with hand flying?

Would you say this is normal? Just asking because it looks kinda weird to me. At the end of the approach I am lined up with the runway...but always thought the autopilot would fly it smoother then me?

 

[cappy48]

Appreciate the feedback Cap! Can I ask you another question?

Since I am new to an AP for approaches I do notice that when on the final LPV approach leg (& coupled) the nose of the plane appears to be making several shallow S-turns on its path to the runway. Some seem like 10-15 degrees. However, the CDI stays pretty centered (Lateral) and the glide scope stays just a tad high (Maybe 1/2 a deflection)...but on GS.

I am thinking that would be normal due to winds and/or thermals...but it seems to be easier/steadier with hand flying?

Would you say this is normal? Just asking because it looks kinda weird to me. At the end of the approach I am lined up with the runway...but always thought the autopilot would fly it smoother then me?

OK, First, important to note that the AP is pretty dumb here, it is just following directions of the navigator. The only thing you can adjust is how it RESPONDS to what your navigator is telling it.

So... first, if the AP is NOT doing this in other flight modes, I would increase the OUTPUT sensitivity on the Navigator.. (I don't have a 430 so others may have to help here) I think the 430 has an adjustment. If the AP "S" turns a bit in other flight situations, increase the gpss or lateral sensitivity on the TT. (depending on what steering signal you are using).

I am not certain if the 430 disables the GPSS in approach mode or not.. Some guys who fly them may be able to assist here.

Will the AP fly the approach better than hand flying? It depends... but in hand flying, capable pilots are probably better. Pilots can anticipate corrections, APs cannot.. If the seat pushes your butt up, you KNOW there is a pitch down correction coming. the AP does not know this until the aircraft actually deviates from the GS... up! The AP (and navigator) can only RESPOND to deviations AFTER they happen.

As for the GS indication, if you (your CDI) are monitoring the ILS, differences are common, if you are monitoring the RNAV input, there may be a bias adjustment you can use, because the navigator is sending different data to the CDI and the AP. or the CDI indicator may need realignment.

FWIW! Good luck!

Cap

 

[Cherokee Lover]

Cap...you seem to be the most knowledgeable on this product so I hope I am not wearing out my welcome here, LOL...but have a few more questions if you don't mind?

The PA-28 installation manual has recommended settings for version PV.40. separating them by lateral and vertical.

I am having ZERO flight issues with vertical.

First...it says use LAT activity of 17. What would be the results if I went higher or lower?

Second...it says set the MICROACTIVITY to 10. Once again...what if I set it higher or lower...what would that cause? What is microactivity?

Third...it says to set the GPSS gain to 16. Once again...what's the effect of higher or lower? What is GPSS gain?

Last...under the vertical section...it says set static lag to 1. What is static lag?

Jim

 

[Cherokee Lover]

BTW...there are only 4 settings the manual (And my G430W) will accept when programming my GPS NAV unit. It has Baud rate and 3 others. The manual doesn't list any others and the G430 won't give me any other options. They are all set correctly. Any setting changes I need to make to correct my lateral issues have to be in the AP.

 

[cappy48]

Cap...you seem to be the most knowledgeable on this product so I hope I am not wearing out my welcome here, LOL...but have a few more questions if you don't mind?

The PA-28 installation manual has recommended settings for version PV.40. separating them by lateral and vertical.

I am having ZERO flight issues with vertical.

First...it says use LAT activity of 17. What would be the results if I went higher or lower?

Second...it says set the MICROACTIVITY to 10. Once again...what if I set it higher or lower...what would that cause? What is microactivity?

Third...it says to set the GPSS gain to 16. Once again...what's the effect of higher or lower? What is GPSS gain?

Last...under the vertical section...it says set static lag to 1. What is static lag?

Jim

No worries Sir.. happy to help if I am able..

OK... first down load this manual for the setup of the EXPERIMENTAL version of the TT Vizion. It has an explanation of the action of the various setting parameters, whereas the PMA version manual does not.. VERY helpful!

https://www.bendixking.com/content/.../Vizion-380-385-Series-Operating-Handbook.pdf

The short version..

Lateral Activity.. higher makes it react sooner and stronger to lateral deviations of course, lower will make it slower to respond.

Micro activity... will make up for slack or "looseness" in the control system. Higher will cause the server to move further to take up " slack" in a cable system before the surface moves, (sort of like an "active wider neutral" ) lower will be used for pushrod systems (like in RVs) that have little or no "slack" ( for instance, if you have Mattson gap seals on the ailerons, you might set it a unit lower, ( they give the plane a higher roll response with no increase in friction, with K2U gap seals, you might wish to up it a bit to overcome the friction of the metal seals.)

GPSS gain will (higher) increase the response to lateral course deviations in GPSS mode. (If your navigator uses GPSS steering in the approach mode, increasing this may lessen the "S" turns you mentioned. If it does not, increasing the "lateral activity" may help. Increasing this may help the "S" turns on approach, but could make it too sensitive in normal (non GPSS steering ) courses.

Static lag (increase) will dampen oscillations in vertical, but make it less sensitive to alt deviations... Careful with this one, talk to TT / BK before making large changes here.

Very few have "tweaked" these setting away from factory suggested, and then not by much. (my vertical activity is upped to 19)

TT must have flown the heck out of this in testing, because almost Cherokees fly "out the door" with the factory settings just fine...

Good luck!

Cap

 

[Cherokee Lover]

Awesome!!! Thanks Cap!

I will wait until the controller is replaced to determine if I need any of these changes. It's unusual because I set my aileron cable tension perfectly before the install...but I do have the Knots 2U gap seals. Might need to adjust microactivity...but I will play with it if needed?

Question...do you agree that the control wheel shouldn't make a full left turn upon power up while on the ground? As you stated earlier I shouldn't have to set the "gyro set" for every flight. There has to be something wrong with the internal gyro. After the "gyro set" it starts off working fine for about 30 minutes...then starts acting up again. After I perform the "gyro set" the control wheel stays steady...until the next day.

 

[Cherokee Lover]

 

[Cherokee Lover]

Cap...the Vision 380-385 discusses gyro trim. I am assuming this is not available on the PV.40 since it goes into "gyro set" not "gyro trim" when you press and hold the knob? Correct?

 

[cappy48]

Awesome!!! Thanks Cap!

I will wait until the controller is replaced to determine if I need any of these changes. It's unusual because I set my aileron cable tension perfectly before the install...but I do have the Knots 2U gap seals. Might need to adjust microactivity...but I will play with it if needed?

Question...do you agree that the control wheel shouldn't make a full left turn upon power up while on the ground? As you stated earlier I shouldn't have to set the "gyro set" for every flight. There has to be something wrong with the internal gyro. After the "gyro set" it starts off working fine for about 30 minutes...then starts acting up again. After I perform the "gyro set" the control wheel stays steady...until the next day.

Correct... It should absolutely NOT turn hard left at power on. There is definitely an issue in the gyro circuit. The gyros are active at power up, and stay "on" in other functions as a "back up" and an SA (Situational Awareness) check at all times .

I am optimistic that a good functioning controller will have you in good order.

You can mess with the micro activity all you wish The plane will go from being "twitchy" and servos buzzing to being very sloppy responding.. like the AP is trying to drive an old truck with a worn out steering box..

 

[cappy48]

Cap...the Vision 380-385 discusses gyro trim. I am assuming this is not available on the PV.40 since it goes into "gyro set" not "gyro trim" when you press and hold the knob? Correct?

I am not sure about this...……. I have not checked this on Version 4.

Good question..

I will ask the man that knows...

Cap

 

[AeroLudite]

FWIW, my installation was right after Cherokee Lovers.
My unit has been flawless since install. However;
My G430 needed an updated operating system to be compatible with the AE100.
That’s why my installation cost a little more.Secondly, my procedure is to power up the avionics (G430) first. Then power up the AE100. After boot up it goes to OFF mode. I then do the altitude sync. I wait till it shows GPS feed active, (flashing +). It never jerks, tweeks or anything. When DG is synced to magnetic compass, the hdg on the AE100 is within 5deg of dg.

It does get a bit “goofy” below 200’ agl on a LPV Apch! but suspending the approach and activating the missed, it climbs if altitude is pre selected. Amazing piece of equipment. (Yeah, I know it’s not APPROVED for under 700agl, but given the variables, it’s understandable.
I’m still learning it. Little things like after a climb to altitude, getting the Altitude into “HOLD” rather than sel or “0”.
Manual could use some simplification, cleaning up, and reorganized format.
Also a quick reference card would be wonderful. Once I get better versed on it, I may make my own.
Photo of flying the RNAV-GPS at KPIM.

I think Cherokee Lovers problem is with the control head. I encountered a similar problem with a STec 55X. With a donor controller, the problem went away. Went back to STec 3rd time. Finally, dealer sent it back and told them it was his unit and got it replaced. Problem solved!

 

[Cherokee Lover]

Cap...the manual also lists the setup in the G430 Main Arinc Config page. It says to set SPEED to "LOW" on this page. Do you know why it's set to low and not high?

 

[flyingcheesehead]

Some have found that the GFC will respond to "Min speed" setting by pushing the nose down when it is turned OFF. (!)

That's a feature... Envelope protection. It's there to keep you from inadvertently stalling in a moment of inattention. It'll also nudge you nose up if you're approaching Vne and nudge you toward level if you're approaching 45/60 degrees (configurable) of bank. It can be turned off for doing maneuvers where you intend to be close to the edges of the flight envelope.

The "Correct" Garmin navigator will "inhibit" this action below 200 ft. GPS altitude. Other navigators will not.

That's an important issue to take note of... Thanks! That's also a good reason not to try to legally wiggle around the requirement for a Garmin navigator when installing a GFC 500.

 

[cappy48]

I am not sure about this...……. I have not checked this on Version 4.

Good question..

I will ask the man that knows...

Cap

OK.... 'Pologies are due here for this late reply... Cappy screwed up.

Was asked this question on another form, and posted Andrews response there, but not HERE! (Cappy hangs head and shuffles feet... )

Again sorry...

Here it is
---------------------------------------------------------------------

Yes, both products have the “Gyro Trim” capability for use only in the Bank Angle select mode. This is covered in section 8.3 of the AeroCruze 100 / PMA Vizion manual:


8.3 Gyro Backup Mode

This mode is the lateral mode available when the RS232 signal from the GPS is lost. It allows selection of a bank angle in either the left or right direction up to 30° of bank. This mode is essentially a wing leveler. Rotate the KNOB to select the desired bank angle. Figure 8.3a shows the gyro backup mode screen.




Figure 8.3a

Altitude select, altitude hold, and vertical speed select modes are still accessible when no GPS signal or fix is available. Figure 8.3b shows a 10-degree left bank and altitude hold at 7000 feet. (see section 5.4.2 for ALT HOLD)




Figure 8.3b


If the autopilot is drifting left or right with 0° selected, the gyro trim needs to be adjusted. Press and rotate the KNOB to access the gyro trim screen. Adjust the gyro trim in the appropriate direction in 0.2°/min increments. Figure 8.3c shows the gyro backup mode screen and the gyro trim screen.

Note: the autopilot may momentarily switch to the AP OFF screen while performing the press of the KNOB, rotating the knob left of right will bring the normal display back into view and the autopilot will not disengage.




Figure 8.3c




Andrew Barker

Vice President - Sales

Experimental & Americas Aftermarket
BendixKing


From: mariners_@rogers.com <mariners_@rogers.com>
Sent: Thursday, July 30, 2020 4:37 PM
To: Barker, Andrew <Andrew.Barker@Honeywell.com>
Subject: Re: [External] Aerocruise


Passed on Andrew...thanks!



Question


Is "Gyro Trim" available on both the experimental Vizion and the certed model on version 4?


I seem to remember using it before but can't seem to engage it again and another TT user has asked as well...

Dave

--------------------------------------------------------------------------------------------------------------------------

IMPORTANT DETAIL!!! (That I and others missed.... )

Gyro "TRIM" is only available when there is NO GPS signal. To adjust the GPS must be discoed with a switch or turned OFF . "NO GPS" must be displayed in the TT Head window.

Cap

 

[cappy48]

FWIW..

BK is now working with a 3rd party STC "house" to push ahead the Mooney version of the AeroCruise (TT) product..

Nav

 

[Cherokee Lover]

FYSA...I had to send my control head back to BK for the 2nd time. Still having issues with GPSS steering not tracking correctly. Had the issue ever since install back in May. Changing GPSS gain and Lat activity had no impact.

I just spoke with Tech at Mid-Continent (BK subs all repairs to them) who conveyed to me that BK confessed that the had GPSS issues being reported on approx 1 in 4 of the new installs within the last 18 months. They claim their engineers are working a software fix. In the interim they are swapping my main board and re-loading the software.

Makes me feel good that I am not crazy...LOL

 

[cappy48]

Hmmm.... something not computing here..

I sent your post on to Andrew, he responded right away.. puzzled as well...

Gona PM you his Email address.. He would like to hear from you on this.. Will you send him some details?

Cap

 

[Cherokee Lover]

I sent him a note.

BTW...for all the forum members on here discussing TT and BK...I read about all the concerns regarding BK taking over TruTrak. I have to admit that I haven't encountered ANY issues with BK (Or their repair sub Mid-Continent) regarding supportability or customer service.

Yes...I am having an issue with my GPSS...but every time I contact the BK tech rep they are very responsive and helpful. They even offered to ship out a new servo if this board didn't fix the issue. Not many companies would do that!

I still love this auto-pilot...and if I had to go back in time I would buy it again! Everything I read and everybody that I talk to that has this system have never seen this problem. I guess like 99.9% of them work flawlessly right out of the box?

I am sure its just a minor glitch and they seem extremely willing to stand behind their product.

 

[AlphaMike]

I have the TT vision in my c182p It holds a heading very well and GPSS is spot on! My issue is with altitude hold. Its hit or miss. Sometimes it will overshoot by as much as 300’ then start porpoising 100’ up and down. I can turn the TT off and then back on again and it seems to settle down. I’ve changed the Vertical activity quite a bit more then the “stock” numbers for the plane and it’s gotten much better, but I still have to watch it closely, especially in turbulence. My 182 has a PPONK engine and a STOL kit so I would expect the standard settings might need some adjustment. The TT was installed just before I bought the plane and the installer is on the other side of the country from me. I’ve talked to support a few times and they have always been good to work with.

 

[Cherokee Lover]

I have heard of a few folks having issues with altitude hold....but NEVER with roll, TRK, or GPSS. I guess mine was the anomaly. I am sure it will be fixed here shortly.

I tell you this though...I did about a dozen mock LPV coupled approaches (VFR conditions) down to about 500'. Even though I had some lateral issues during other parameters...when it coupled it was no kidding flying like it was on a rail! It had me perfectly lined up with the runway and my CDI needles were dead on! This sucker gets down to business when on the final leg of the approach...that's for sure!

 

[AlphaMike]

I 100% agree! I’ve shot a bunch of LVP approaches and once it switches to coupled it locks in and does a great job on the approach. The other time I have an altitude issue is when flying a hold or PT. Mine has a hard time holding altitude in a hold.

 

[cappy48]

I sent him a note.

BTW...for all the forum members on here discussing TT and BK...I read about all the concerns regarding BK taking over TruTrak. I have to admit that I haven't encountered ANY issues with BK (Or their repair sub Mid-Continent) regarding supportability or customer service.

Yes...I am having an issue with my GPSS...but every time I contact the BK tech rep they are very responsive and helpful. They even offered to ship out a new servo if this board didn't fix the issue. Not many companies would do that!

I still love this auto-pilot...and if I had to go back in time I would buy it again! Everything I read and everybody that I talk to that has this system have never seen this problem. I guess like 99.9% of them work flawlessly right out of the box?

I am sure its just a minor glitch and they seem extremely willing to stand behind their product.

---------------------------------------------------------------------

I was one of the first to get the TT. ands I hit the "roll servo arm issue". When I called about it they had just got off the phone with another customer with the same problem!

They were all over it! Pictures were sent, some phone time and a "work around " was found within a few hours and the alternate arm redesigned with a week. Unfortunately the first batch of arms from their supplier were ALL defective. Changed supplier. New arms overnighted to customers as soon as they arrived.. (I think BOTH arms are shipped with app units now incase needed..)

They were never able to nail down the issue to a type or serial number pattern within the PA-28s.

Although a hiccup, It sure gave me an insight into how TT looked after these issues.

No issues here since BK, but my software upgrade through BK went timely and well. Mid-Continent were great to deal with. Best customer service by far of any company represented in my panel.

No one can bat 1000, but so far no complaints here.

Customer service is relatively easy when things go well, but the real test of a supplier comes when something skids off the turn. Then the cream really rises to the top...

Cap

 

[cappy48]

I have heard of a few folks having issues with altitude hold....but NEVER with roll, TRK, or GPSS. I guess mine was the anomaly. I am sure it will be fixed here shortly.

I tell you this though...I did about a dozen mock LPV coupled approaches (VFR conditions) down to about 500'. Even though I had some lateral issues during other parameters...when it coupled it was no kidding flying like it was on a rail! It had me perfectly lined up with the runway and my CDI needles were dead on! This sucker gets down to business when on the final leg of the approach...that's for sure!

-----------------------------------------------------------------------------------------------------

A pilot with a IFD 440 and a TT mailed me last year about his test. 3 Coupled approaches, (VFR of course) , 6 K Xwind component in an Archer. He managed the throttle flaps and trim. All three times he discoed the AP at 5 ft. over the centerline , checked descent and flared. He felt the plane was "stuck" to the GS and LOC. He was especially impressed how accurately the plane corrected and returned to the centerline within some wind gusts..


Cap

 

[cappy48]

I have heard of a few folks having issues with altitude hold....but NEVER with roll, TRK, or GPSS. I guess mine was the anomaly. I am sure it will be fixed here shortly.

I tell you this though...I did about a dozen mock LPV coupled approaches (VFR conditions) down to about 500'. Even though I had some lateral issues during other parameters...when it coupled it was no kidding flying like it was on a rail! It had me perfectly lined up with the runway and my CDI needles were dead on! This sucker gets down to business when on the final leg of the approach...that's for sure!

---------------------------------------------------------

Mine would loose some alt in the 180s at the ends of the hold, but would climb back up to recover. I cranked up the vert activity to 19 and almost no deviation now. (1976 Warrior)

 

[AlphaMike]

I’m up to 24 now on the vertical activity. Started at 17. It’s gotten better but isn’t perfectly consistent. Sometimes it’s good and I only lose 100’ or so in a turn and starts to recover and other times I have to disconnect it and hand fly to recover. I’m going to make another bump up on the VA to 26 and see how it reacts. It seems like it’s just slow to react to altitude. If I set altitude 7000 and a climb rate at 800 fm it doesn’t just start the climb right away. There’s a solid 20 second delay then it slowly starts to climb and eventually will get to 800fm. That’s at 110 knots. I find if I start the climb myself, then turn on the AP it holds the climb rate better. As far as holding altitude in a turn I’ve been adding a little power and some trim just to help it but it still loses 50’ or more. It’s definitely worse if there’s some turbulence. If it’s super smooth air it does better.

 

[cappy48]

I’m up to 24 now on the vertical activity. Started at 17. It’s gotten better but isn’t perfectly consistent. Sometimes it’s good and I only lose 100’ or so in a turn and starts to recover and other times I have to disconnect it and hand fly to recover. I’m going to make another bump up on the VA to 26 and see how it reacts. It seems like it’s just slow to react to altitude. If I set altitude 7000 and a climb rate at 800 fm it doesn’t just start the climb right away. There’s a solid 20 second delay then it slowly starts to climb and eventually will get to 800fm. That’s at 110 knots. I find if I start the climb myself, then turn on the AP it holds the climb rate better. As far as holding altitude in a turn I’ve been adding a little power and some trim just to help it but it still loses 50’ or more. It’s definitely worse if there’s some turbulence. If it’s super smooth air it does better.

--------------------------------------

Hmmmmm.... Thinking.. Try reducing the static lag to "0".

My experience is with the Pipers so a bit blind here.. In Pipers, the "stiction" on the yoke tubes is suspect as is the cable tension on the pitch cables... Most vertical issues are solved by lubing the yoke tubes and setting the cable tensions correctly..

Maybe?

Also, any suggestions on the Cessna Forums? Lots of TT APs installed in Cessnas….

Cap

 

[AlphaMike]

Thanks for you help crappy! Static lag is at 0. I’m sure it’s just a matter of getting all the settings dialed in. I doubt it’s a cable or rigging issue because it flys the glide slope perfect yet if I set it for a regular decent it does the same thing that it does in a climb. I believe when it’s fallowing the GS it’s more sensitive and reactive. I just need to find that sweet spot in the settings. That’s one of the minuses of having a heavenly modified aircraft. You can’t just plug in and use standard numbers. Some stuff you just need to figure out what works. My VX, VY speeds are different, my stall speeds are way different, my climb rate is way different, from POH numbers. It would be impossible for TT to know what should work on my plane out of the box.

 

[cappy48]

Thanks for you help crappy! Static lag is at 0. I’m sure it’s just a matter of getting all the settings dialed in. I doubt it’s a cable or rigging issue because it flys the glide slope perfect yet if I set it for a regular decent it does the same thing that it does in a climb. I believe when it’s fallowing the GS it’s more sensitive and reactive. I just need to find that sweet spot in the settings. That’s one of the minuses of having a heavenly modified aircraft. You can’t just plug in and use standard numbers. Some stuff you just need to figure out what works. My VX, VY speeds are different, my stall speeds are way different, my climb rate is way different, from POH numbers. It would be impossible for TT to know what should work on my plane out of the box.

----------------------------------------------------

Hi Mike!

Understood and your logic is sound..

On the TT , alt targets and hold are referenced to static pressure and that is where static lag and Vert Activity tweaks come into play. But when "coupled" the AP takes direct steering inputs from the navigator with NO reference to the static source, so very a different response from the AP. It just "flies the needles" like you would hand fly the ILS. Try upping the static lag... What is the factory recommended setting for the Cessna?

Hear you on the mods..

We have the Mattson seals and VGs on our Cherokee, and it is a different aircraft. POH does not apply!

Some things have to be tweaked... Like yours, our V speeds are all different...

Cap

 

[AlphaMike]

----------------------------------------------------

Hi Mike!

Understood and your logic is sound..

On the TT , alt targets and hold are referenced to static pressure and that is where static lag and Vert Activity tweaks come into play. But when "coupled" the AP takes direct steering inputs from the navigator with NO reference to the static source, so very a different response from the AP. It just "flies the needles" like you would hand fly the ILS. Try upping the static lag... What is the factory recommended setting for the Cessna?

Hear you on the mods..

We have the Mattson seals and VGs on our Cherokee, and it is a different aircraft. POH does not apply!

Some things have to be tweaked... Like yours, our V speeds are all different...

Cap

just wanted to update. I’ve finally got my TT dialed in! It took a lot of messing around with the settings but it now seems to hold altitude very well. Ended up with static lag set to 0. Recommended setting is 2. And the vertical activity is now at 28. Recommend setting was 17. My plane is no we’re near stock so it makes sense I had to modify some of the settings. I’ve made several flights In smooth and bumpy air and it’s pretty dang solid! I’m very happy with my TT now!