Garmin G1000 ?

[mike_elliott]

21 hours ago, GeeBee said:

Here is my view. I actually sought out a G1000 with an STec 55X. Why? If you loose the AHARs on such an aircraft you still have an autopilot because the STec is a rate based unit that will continue to function despite loss of the AHARs and the associated attitude indicator. Cannot do that with a GFC 700 unit. so at a time of high stress and workload, with the STec equipped G1000, you still can use the autopilot. 

...and you have a turn coordinator hidden behind all that glass to drive the stec that can fail

[Jeff_S]

Here’s something to consider about the WAAS upgrade for the G1000/S-TEC folks (of which I am one). Not only do you get WAAS, but you get an updated version of the G1000 software which gives you some nice features that I use all the time. For example, when flying a descent or ascent to a target altitude, the MFD will display the location where you should hit that altitude...very handy when trying to get above or below an airspace while flying VFR, or when descending toward and airport. Do I hear “cross at or below x altitude”?

Also, the FltPlan view allows you to switch between Leg and Cumulative view so you can see how far to your end destination...very handy when announcing your distance to an airport when flying practice approaches in VFR. And perhaps most important, this version of software allows capture of the flight log data on the SD card in the upper slot of the MFD, which you can then import into Savvy Analysis or CloudAhoy to help with engine monitoring, flight skill tracking, etc. 

I’m sure there a few other things that it does as well. Oh, and one more thing: the official documentation may still say that this setup is not approved for coupled LPV approaches...but that doesn’t mean it won’t do them! 

[GeeBee]

21 hours ago, mike_elliott said:

...and you have a turn coordinator hidden behind all that glass to drive the stec that can fail

Yes, you do, but it is one more, not one less and that creates greater redundancy. You cannot argue with the AHARS goes Tango Uniform on a GFC-700 you are out of autopilot.....just at the time when you need it the most, unless you like hand flying cross panel in IMC. Personally if I had a GFC-700 I would look to install a backup such as a G5 or GI-275 in the backup instruments hole that I could switch the GFC-700 to in the event of AHARS failure. I would much rather have a dedicated gyro to the AP than have the AP dependent upon the PFD.

 

[MatthiasArnold]

Hi Matt,

I recently purchased an O2 GX with G1000 non WAAS and STEC55X.
Thanks to MooneySpace I was aware of the pros and cons of this setup.

However, I decided for this nice aircraft for several reasons:

• I'm a tech guy (Electronics Engineer, Computer Scientist, IoT consultant),
  • I really enjoy the high degree of information integration that G1000 provides!
• It was very low time (app 370h SNEW), with all its pros and some cons (see Mike Busch "Engines")
• It was (and is) very well equipped (TKS FIKI, Oxygen, AC, ..)
• I want this aircraft as my "forever" plane

As other's mentioned before it really come's down to personal taste and preferences..

I'm currently going through the adventure of WAAS upgrade. Imho it's even more challenging on the old continent (I live in Germany) than in the new world..

• Trying to source used GIA63W in the US (in progress, some obstacles, ..)
• Finding an avionics shop / MSC who already did some of the upgrades before (found one)

If your interested I can provide some additional information once I achieve some progress (or get stalled & frustrated..).

Regards,

Matthias

[mike_elliott]

20 minutes ago, GeeBee said:

Yes, you do, but it is one more, not one less and that creates greater redundancy.

Is there a second one that also drives the STEC? I was under the impression it was the SOLE driver of the Stec autopilot and why it is needed, albeit hidden. Please correct me if I am wrong.

[MatthiasArnold]

The "secondary" TC driving the STEC55X is hidden behind the MFD - I really started laughing when I detected it the first time:
 

[GeeBee]

5 minutes ago, mike_elliott said:

Is there a second one that also drives the STEC? I was under the impression it was the SOLE driver of the Stec autopilot and why it is needed, albeit hidden. Please correct me if I am wrong.

You are not getting it. So let me run you through the scenarios.

Scenario 1

You are flying along in IMC with a GFC-700. Your AHARs goes Tango Uniform. You now have no autopilot AND NO PFD. You are going to be hand flying the airplane. Your attitude will come from the AI across the panel. Your heading from the wet compass. You now have to look at an approach chart, tune radios and get the airplane down, all hand flying in IMC across the panel looking at the little AI. You will have to track an approach course with a wet compass hand flying from the little AI across the cockpit.

Scenario 2

You are flying along in IMC with an STec/G1000. Your AHARs goes Tango Uniform. You have now have no PFD. You however can continue to use the A/P and verify its performance with the AI across the panel. You can hold a heading by using the heading bug on the PFD and verifying it on the wet compass. You can easily reference the approach chart and descend the airplane on the autopilot, track the approach course with the A/P. in heading until you break out.

Scenario 3

You are flying along in IMC with an STec/G1000. The A/P will not hold the wings level and you suspect the gyro behind the panel has failed. You will be hand flying the airplane, but you will have the giant PFD right in front of you, not the little one across the panel. You will descend and shoot the approach manually using the BIG PFD right in front of you.

 

Now, out of those three scenarios, all of which have an attitude failure, which one would you rather NOT fly?

[mike_elliott]

I get what you are saying, but you are not answering my question. Ill repeat it..

"Is there a second one that also drives the STEC? I was under the impression it was the SOLE driver of the Stec autopilot and why it is needed, albeit hidden. Please correct me if I am wrong"

If there is not a second TC that also drives the STEC, your AP doesnt have redundancy, Agreed?

[GeeBee]

29 minutes ago, mike_elliott said:

I get what you are saying, but you are not answering my question. Ill repeat it..

"Is there a second one that also drives the STEC? I was under the impression it was the SOLE driver of the Stec autopilot and why it is needed, albeit hidden. Please correct me if I am wrong"

If there is not a second TC that also drives the STEC, your AP doesnt have redundancy, Agreed?

Absolutely, but the question is what is your next move after a single failure of its primary input. One is very difficult, the other is ordinary flying.

 

[mike_elliott]

Again, I see your point, which is made moot with the new Ultra's and their redundancy. They still have a single point of AP failure, as they all do. The Sturn 55 was a great AP in "the day" and sure beats not having one. Today, the Garmin is just that much better and not subject to the electric TC spinning up/failures of the older tech. A shame Genesys doesnt make the 3100 available as a drop in replacement for the 55 

[MatthiasArnold]

14 minutes ago, mike_elliott said:

A shame Genesys doesnt make the 3100 available as a drop in replacement for the 55

Absolutely!

[GeeBee]

Three points. 

I don't have a half million dollars to move the back up AI to the center of the panel.

I have hand flown several approaches on those "little" back up AI in the simulator. The last being on an A330 into Beijing. Not easy, not comfortable. If I got to hand fly the airplane during a failure, I want a BIG PFD in front of me.

[kortopates]

I would also point out that if we could equate the realistic failure statistics to the 3 scenarios @GeeBee outlined, Scenario 1, where a full AHRS failure is considered is not going to be the failure mode to be concerned with. It is the worst case scenario of the that configuration but but less likely that the others. First off, the Stec Turn-coordinator has a far greater chance of failing before a complete G1000 AHRS does. Now if our AHRS was a first generation Aspen AHRS I probably would have used the same failure scenarios. But the G1000 is AHRS is not vulnerable to a single input going bad which brings down your entire AHRS like the original Aspen did such as a loss of Air Data. To bring down the entire Garmin AHRS its takes total loss of both Air Data and both GPS's (see emergency procedures in the G1000 AFMS.) With any one individual loss we'll see degraded or partial AHRS capability.

And with at least 1 GPS we will still have ground track information for heading and desired track to to steer with out needing to resort to the compass. Buts its because of the more advanced Garmin AHRS that fails gradually that Garmin doesn't really need a second AHRS.

But still, in the vast majority of G1000 installations, you will have a GTX-345 that provide backup AHRS for your doomsday failure mode. It won't provide it to the panel or GFC700 but it will to your iPad and that along with  a backup portable GPS can get you down. Chances of needing that capability in low IMC conditions is pretty minute since it will require both a loss of Air Data, such as a pitot heat failure in icing conditions, and loss of both GPS's from perhaps jamming or interference testing. I've experienced loss from jamming 3 times now and every case it lasted no more than 20 minutes - thankfully only once was in IMC. 

Reversionary mode is a really slick and automatic with the Mooney G1000 implementation. For example with PFD failure, it automatically goes into the reversionary mode bringing up the PFD on the MFD. The downside of this though is that when you loose either the PFD or MFD you loose the GIA-63(w) associated with that screen - you're down to one even though it none actually failed - so just one Nav Com to work with. 

But there are far better backup options for the g1000 today rather than the limited Attitude gyro with Altimeter and Airspeed such as the ESI-500 which is like a mini Garmin or Aspen and includes navigation. I'd rate that as a  better option over a G5.

So as much as I like the STEC AP's independence on a traditional 6 pack panel, I'll  happily keep that GFC700 on a G1000 panel.

Edited October 20, 2020 by kortopates

[carusoam]

1 hour ago, mike_elliott said:

Again, I see your point, which is made moot with the new Ultra's and their redundancy. They still have a single point of AP failure, as they all do. The Sturn 55 was a great AP in "the day" and sure beats not having one. Today, the Garmin is just that much better and not subject to the electric TC spinning up/failures of the older tech. A shame Genesys doesnt make the 3100 available as a drop in replacement for the 55 

Mike,

was there a vid to go with this?

Something went awry before I got to it... 

 

Best regards,

-a-

[carusoam]

1 hour ago, GeeBee said:

You are not getting it.

Kind of a strong statement considering the company in the room... 
 

MS is often a test of one’s writing skill, and control...
 

Speed without control is nothing.... -Pirelli

Control is everything....

Best regards,

-a-

[mike_elliott]

14 minutes ago, carusoam said:

Mike,

was there a vid to go with this?

Something went awry before I got to it... 

 

Best regards,

-a-

No it just shows the Ultra's  backup instruments in case you lose your primary attitude heading and reference source or your PDF and MDF go BK on you.

[GeeBee]

I've flown a lot of AHRS in my life, most notably on the MD airplanes. They are not as reliable as one would think. So much so, the airlines removed them at great expense went to full IRU's. 

The failure of some AHRS can come from lack of inputs such as pitot static and yes Garmin uses GPS inputs to overcome that failure point, but nothing, nothing in this world will keep AHRS working when those piezo electric sensors fail.

 

"Losing heading and attitude reference is one of the most debilitating failure modes. It forces you to use the standby attitude indicator, breaking your normal scan."

http://www.fredonflying.com/Articles/IFR_Refresher/1004-G1000-Failure-Modes.pdf

Do you really want to be out of normal scan, with no autopilot?

Nope, not me.  

When I am up to my butt in alligators, I don't need to start bleeding into the pool.

 

 

[kortopates]

42 minutes ago, GeeBee said:

I've flown a lot of AHRS in my life, most notably on the MD airplanes. They are not as reliable as one would think. So much so, the airlines removed them at great expense went to full IRU's. 

The failure of some AHRS can come from lack of inputs such as pitot static and yes Garmin uses GPS inputs to overcome that failure point, but nothing, nothing in this world will keep AHRS working when those piezo electric sensors fail.

 

"Losing heading and attitude reference is one of the most debilitating failure modes. It forces you to use the standby attitude indicator, breaking your normal scan."

http://www.fredonflying.com/Articles/IFR_Refresher/1004-G1000-Failure-Modes.pdf

Do you really want to be out of normal scan, with no autopilot?

Nope, not me.  

When I am up to my butt in alligators, I don't need to start bleeding into the pool.

Absolutely it can happen and does happen and Fred does an awesome job of going through the G1000 failure modes. And shortly after posting I did hear from another G1000 pilot whom told me about their personal AHRS failure so I won't disagree that total AHRS failures probably do happen more than we would expect. But we know its rare since its takes a lot before we entirely lose a Garmin AHRS unlike some of the less robust early GA offerings out there - but yes the doomsday scenario is still possible and much more so in a single engine GA aircraft like our Mooney's. But we can and should incorporate partial panel training in our currency training. But if I could, I would reference statistical odds of failures in our GA aircraft and would expect this is pretty far down the list but unfortunately we really only have reliable statistics from those failures that make the NTSB files. 

The good thing is that you do understand the failure modes and how it effects your panel capabilities, given your professional pilot background. The unfortunate thing as glass and avionics  has evolved into what the FAA refers to as Technically Advanced Airplanes, fewer and fewer  GA pilots really do understand their own aircraft specific system dependencies and failure modes until they experience one.

  

[GeeBee]

I will say this. I am more sensitive to AHRS failures maybe more than most. On my initial Captain's ride, with the FAA on the jump seat, coming out of RIC to ATL I had double AHRS failure that required a divert to GSO. I passed the ride because I made the right decisions about the necessity of a divert but the point is when it comes to AHRS, I like it better than gyros, but it is like my self driving car. I don't trust it.

As for practicing failures, I agree. My practice however indicates flying on a little standby instrument without an A/P is not where you want to be, or should be and I am willing to accept something less than a GFC-700 if it will keep the wings level in that kind of situation. The help does not have to be perfection, it just needs to work.

 

[MooneyMitch]

1 hour ago, kortopates said:

fewer and fewer  GA pilots really do understand their own aircraft specific system dependencies and failure modes until they experience one.

Could one apply this statement to Lion Air/Ethiopian Airlines MAX crashes?  Yes, I know the system tech. inadequacies too.

[kortopates]

24 minutes ago, GeeBee said:

I will say this. I am more sensitive to AHRS failures maybe more than most. On my initial Captain's ride, with the FAA on the jump seat, coming out of RIC to ATL I had double AHRS failure that required a divert to GSO. I passed the ride because I made the right decisions about the necessity of a divert but the point is when it comes to AHRS, I like it better than gyros, but it is like my self driving car. I don't trust it.

As for practicing failures, I agree. My practice however indicates flying on a little standby instrument without an A/P is not where you want to be, or should be and I am willing to accept something less than a GFC-700 if it will keep the wings level in that kind of situation. The help does not have to be perfection, it just needs to work.

 

Wow, that's a hell of a check ride! Double AHRS failures with (I assume) both check pilot and FAA guy onboard! That must have been intimidating to begin with but I guess you were too busy dealing with the issues to worry about them much  

I hear you on the "It just needs to work" statement. I felt very much the same way about the GFC-500 AP when we learned it was dependent on GPS to fly approaches. I very much would prefer the GFC-600 solution (pretty much the retrofit version of the 700) but that is both much more expensive and not available (yet). I still don't know but have warmed up considerably to the limitations of the GFC based on the probabilities. These are not easy tradeoff's give the $.

[kortopates]

19 minutes ago, MooneyMitch said:

Could one apply this statement to Lion Air/Ethiopian Airlines MAX crashes?  Yes, I know the system tech. inadequacies too.

Yes, but they don't really seem comparable. WRT to GA technology the information is generally available to pilot and the learning the system and failure modes is the responsibility of the pilot, but the pilots of the MAX crashes where not only victims of unanticipated single source of failure but also were not afforded training on the new system due to no fault of their own but of the manufacturer - at least as best as I recall. 

[MooneyMitch]

29 minutes ago, kortopates said:

Yes, but they don't really seem comparable. WRT to GA technology the information is generally available to pilot and the learning the system and failure modes is the responsibility of the pilot, but the pilots of the MAX crashes where not only victims of unanticipated single source of failure but also were not afforded training on the new system due to no fault of their own but of the manufacturer - at least as best as I recall. 

Yes, but, flying the airplane into the ground with full power seems a little odd to me. 

I blame technology and I blame lack of pilot skills....... my simple opinion on a highly complicated issue 

[GeeBee]

1 hour ago, MooneyMitch said:

Yes, but, flying the airplane into the ground with full power seems a little odd to me. 

I blame technology and I blame lack of pilot skills....... my simple opinion on a highly complicated issue 

If you have ever engage the stab trim brake on a Boeing, it is more complex than you think. To give you an example, after a long transoceanic flight as we were going feet dry near Lands End, I got a "Stab Out Of Trim" warning. The autopilot was not trimming the stab so it made up for it with the elevator servo pulling stick back. It pulled back enough that it engaged the stab trim brake. The only way to disengage the brake is to move the stick forward so the brake disengages then retrim the stab. At FL 390, a move of stick forward is going to create some real vertical speed. I had to sit everyone down, get a block altitude assignment. We went a little light in the seat as I pushed the stick forward sufficiently to release the brake, then retrim the stab. 8000' of loss.

If you were one of those poor souls in a Max and you see the stab trimming forward without significant speed drop, you pull back on the elevator. At that point the stab trim brake engages, because you have stick movement opposite to trimming action. The airplane is nose high and you don't want to reduce power significantly because you are near V2. You have no choice but to go forward stick to try and unlock the stab. Then you go lawn dart.

The 707 and 727 had stab trim brake unlock where you could unlock the stab trim brake without moving the elevator. That was removed on subsequent models.

The Max is an excellent example of the threat to sole source data to flight control systems. Before you install fancy "self landing systems" a switching box to the backup attitude indicator for the autopilot would mitigate a greater threat. Garmin, are you listening? 

[MooneyMitch]

47 minutes ago, GeeBee said:

If you have ever engage the stab trim brake on a Boeing, it is more complex than you think. To give you an example, after a long transoceanic flight as we were going feet dry near Lands End, I got a "Stab Out Of Trim" warning. The autopilot was not trimming the stab so it made up for it with the elevator servo pulling stick back. It pulled back enough that it engaged the stab trim brake. The only way to disengage the brake is to move the stick forward so the brake disengages then retrim the stab. At FL 390, a move of stick forward is going to create some real vertical speed. I had to sit everyone down, get a block altitude assignment. We went a little light in the seat as I pushed the stick forward sufficiently to release the brake, then retrim the stab. 8000' of loss.

If you were one of those poor souls in a Max and you see the stab trimming forward without significant speed drop, you pull back on the elevator. At that point the stab trim brake engages, because you have stick movement opposite to trimming action. The airplane is nose high and you don't want to reduce power significantly because you are near V2. You have no choice but to go forward stick to try and unlock the stab. Then you go lawn dart.

The 707 and 727 had stab trim brake unlock where you could unlock the stab trim brake without moving the elevator. That was removed on subsequent models.

The Max is an excellent example of the threat to sole source data to flight control systems. Before you install fancy "self landing systems" a switching box to the backup attitude indicator for the autopilot would mitigate a greater threat. Garmin, are you listening? 

I’d be most curious if any other MAX pilot (s) experienced the situation of the two crashed 737’s, and obviously overcame the issue. Anyone know first hand of such?