G1000 Approaches

[mpartovi]

Flew my IPC last night after a few cancellations with my CFII. The G1000 was AWESOME!!! I was pretty confident with my Instrument flying, but the G1000 made my approaches go flawlessly. The biggest obstacle I had to overcome was knowing what to do with ALL that info being presented!

Unusual Attitudes into an imaginary 5DME Arc JOT for the VOR A @ 1C5 went missed over JOT
ILS 9 @ ARR missed to a hold over JOT
GPS B @ 1C5 Partial Panel

...and we called it a night.

The G1000 makes IFR super-duper easy and those HUGE screens really help to visualize whats going on and help you stay ahead of the plane.

I recommend everyone at least give it a try...even if you're a die-hard steam gauge fan.

 

[Nav8tor]

Flew my IPC last night after a few cancellations with my CFII. The G1000 was AWESOME!!! I was pretty confident with my Instrument flying, but the G1000 made my approaches go flawlessly. The biggest obstacle I had to overcome was knowing what to do with ALL that info being presented!

Unusual Attitudes into an imaginary 5DME Arc JOT for the VOR A @ 1C5 went missed over JOT
ILS 9 @ ARR missed to a hold over JOT
GPS B @ 1C5 Partial Panel

...and we called it a night.

The G1000 makes IFR super-duper easy and those HUGE screens really help to visualize whats going on and help you stay ahead of the plane.

That's great! Glad to hear it went so well.

A couple of questions:
1)How much time did you have flying with the G1000 before your IPC?
2) How is partial panel accomplished? Was it done by reference to the back up steam gauges?

Lee

 

[mpartovi]

That's great! Glad to hear it went so well.

A couple of questions:
1)How much time did you have flying with the G1000 before your IPC?
2) How is partial panel accomplished? Was it done by reference to the back up steam gauges?

Lee

I would have to say I had almost 4 hours on the G1000 before my IPC. Most of which was from my biennial and DA40-180 checkout. The G1000 is like any other GPS...just on a BIGGER scale. GPS's are like books...theres nothin to them...they have chapters and pages. Just learn their "table of contents" and you should be all set. The transition from steam to glass was ALOT easier than i expected. I've heard that "video-game era" people have it easier as far as transitioning...but then again...I never played video games.

As for PP...we couldn't actually "fail" any instruments...so my CFII dimmed the PFD till it went black...then i just pushed the ONLY red button there is on the panel to switch to the MFD. I flew my approach from the right screen. The only time you want to engage the steam gauges is when you have TOTAL failure (which is very unlikely). And even then...once the copper wire that seals the "emergency switch" is broken...the G1000 is no long IFR approved...so you'd better be seein the sun.

 

[jdwatson]

Can one fly DME arc approaches with the G1000 ?
Like this one:
KMTN VOR/DME OR TACAN Z RWY 15

 

[TangoWhiskey]

once the copper wire that seals the "emergency switch" is broken...the G1000 is no long IFR approved

What copper wire on what switch? Is this something specific to the DA40's G1000 implementation?

 

[mpartovi]

Can one fly DME arc approaches with the G1000?

Unless I'm not seeing something I dont see why you wouldn't be able to fly that. Just select that particular approach from the menu and activate it and you should be set.

What copper wire on what switch? Is this something specific to the DA40's G1000 implementation?

Quite possibly...as i've never flown anything else with the G1000. The Cessna's may not have it...but if you want to flip up the red casing to start the back-up gauges...you have to break a very thin copper wire that's safety tied around it. Once this has been broken...the DA40 is no longer IFR approved.

 

[TangoWhiskey]

Quite possibly...as i've never flown anything else with the G1000. The Cessna's may not have it...but if you want to flip up the red casing to start the back-up gauges...you have to break a very thin copper wire that's safety tied around it. Once this has been broken...the DA40 is no longer IFR approved.

That is the difference. The backup instruments are always "live" in the Cessna, there is no need to 'activate' them. That concerns me... must have an electric attitude indicator? What happens if you turn the backup instruments on in an unusual attitude? Would the AI spin up quickly enough--and even if they did, would they show a valid "attitude"??

 

[mpartovi]

That is the difference. The backup instruments are always "live" in the Cessna, there is no need to 'activate' them. That concerns me... must have an electric attitude indicator? What happens if you turn the backup instruments on in an unusual attitude? Would the AI spin up quickly enough--and even if they did, would they show a valid "attitude"??

Can't say I've tried them...or know much about the electric attitude indicators...but it does have a dial that says "pull to erect."

From what I understand...the only instrument thats not "live" is the AI. The switch to flip the Emergency Horizon "on" will power it for 1.5 hours.

 

[poadeleted20]

Can one fly DME arc approaches with the G1000 ?
Like this one:
KMTN VOR/DME OR TACAN Z RWY 15

Can you? Probably. Is it legal? Not unless there's a DME in the plane.

 

[ggroves]

The only time you want to engage the steam gauges

If this is correct, then this is a really POOR design. Practicing partial panel on the steam gauges should be a very frequent training exercise.

Garmin's own document on PTS testing using the G1000 gives 4 practice scenarios...2 of which require using the backup AI. Practicing failure of the AHRS cannot be accomplished.

http://nhwgcap.org/ops/AC_Info/G1000/garmin_g1000_guidance_letter.pdf#search='g1000%20failure'

TOTAL failure (which is very unlikely)

Hmmm..there is currently quite a debate on glass panel training. My fear is that it breeds WAAAYYY too much confidence, especially for new IR pilots. It is a nice system, there is no doubt about that, but....everything fails, at one point or another.

Cessna, Mooney, and Piper's backup steam gauges are active, all the time...for a reason.

Greg
CFII

 

[Joe B]

Can one fly DME arc approaches with the G1000 ?
Like this one:
KMTN VOR/DME OR TACAN Z RWY 15

That'll depend on the aircraft. According to the Garmin site the G1000 is "WAAS upgradeable". Without WAAS the GPS falls under TSO C129A which means AIM 1-1-19 f.(b)(6) apply: "Charted requirements for ADF and/or DME can be met using the GPS system, except for use as the principal instrument approach navigation source." That means you can't fly a DME arc. If the GPS is upgraded to WAAS then it falls under a different TSO, probably C146A, and can be used as the primary source of navigation in all phases of flight per AIM 1-1-20.

Regards,
Joe

 

[flyingcheesehead]

Unless I'm not seeing something I dont see why you wouldn't be able to fly that. Just select that particular approach from the menu and activate it and you should be set.

It is NOT legal to fly a DME arc using GPS, so the answer is no, UNLESS you have a "real" DME. The G1000 will interface with "real" DME boxes, as well as the KR 87 ADF (!) and will display their information on the PFD.

Quite possibly...as i've never flown anything else with the G1000. The Cessna's may not have it...but if you want to flip up the red casing to start the back-up gauges...you have to break a very thin copper wire that's safety tied around it. Once this has been broken...the DA40 is no longer IFR approved.

IIRC, the electric AI on the DA40 is always operational, the switch simply isolates it completely from the rest of the plane's electrical system.

Cessna actually has a vacuum pump simply to run the backup AI, and doesn't have the switch-and-wire setup being described here.

 

[biskeyboy]

Can you? Probably. Is it legal? Not unless there's a DME in the plane.

Originally Posted by flyingcheesehead
It is NOT legal to fly a DME arc using GPS, so the answer is no, UNLESS you have a "real" DME. The G1000 will interface with "real" DME boxes, as well as the KR 87 ADF (!) and will display their information on the PFD. .

so AOPA is wrong? or am I misreading this?
http://www.aopa.org/whatsnew/air_traffic/gps_in_lieu.html

"DME arcs associated with instrument approaches may be flown using GPS distance provided the DME transmitter, on which the arc is based, is identified in the GPS database (see Figure A). "

 

[TMetzinger]

IFR GPS systems used to be allowable in lieu of DME for a limited subset of operations, but those restrictions seem to be gone from the new AIM. (Joe's version earlier is no longer accurate, as there's no longer a 1-1-19.f.b.6.) Kent's previous advice is now also wrong, as the table 1-1-6 in the current AIM states that an IFR GPS can be used in lieu of DME (current database required).

1-2-3 was revised, and makes it clear that an RNAV system based on GPS (including standalone GPS systems compliant with AC90-100 - now 90-100A which includes C129 IFR GPS systems) can be used to fly a DME arc. See 1-2-3.c.5. The restriction on not using GPS to substitute for a navigation aid providing lateral guidance for the final approach segment is still present in 1-2-3.c.3, but they took DME out of that paragraph, leaving in VOR, NDB and compass locators.

It's still far from the plain english I'd like to see, but it's clear to me that if the G1000 system will load a procedure from the database, you can fly it.


As I read this, you can absolutely fly a DME arc with IFR GPS unless that arc is part of the final approach segment, and even then it might be permissible, depending on how you parse 1-2-3.c.5.

 

[TangoWhiskey]

GPS can be used in lieu of DME. DME arcs associated with instrument approaches may be flown using GPS distance provided the DME transmitter, on which the arc is based, is identified in the GPS database. I've flown the VOR RWY 14 approach into KACT, from OVFAC IAF, using the G1000 (no DME in the plane); it's in the database, draws the arc on the screen, and flies it just fine:

http://204.108.4.16/d-tpp/0801/00439V14.PDF

 

[sba55]

IIRC, the electric AI on the DA40 is always operational, the switch simply isolates it completely from the rest of the plane's electrical system.

Yeah. The OP might want to check if the backup AI really isn't working as that might be a failure of the AI.

I have about 50 hours in a DA40 180 and I don't believe that you had to "activate" the backup AI. There was that emergency switch, but that's to power the backup instruments (no vacuum system, so all electric) using a small battery.

Also, you can fail instruments with the G1000 by pulling circuit breakers. You can even reset them while in flight.

-Felix

 

[gprellwitz]

Also, you can fail instruments with the G1000 by pulling circuit breakers. You can even reset them while in flight.

-Felix

I've been told that pulling the circuit breaker is not the recommended way to simulate instrument failures. Among other things, I think it disables the transponder, too, depending on the plane. Check the POH and trace the electrical diagram.

 

[sba55]

I've been told that pulling the circuit breaker is not the recommended way to simulate instrument failures. Among other things, I think it disables the transponder, too, depending on the plane. Check the POH and trace the electrical diagram.

Obviously, there isn't just on circuit breaker for the G1000-related systems. I don't remember the details, but one could fail just parts of the system while leaving others intact. I found it to be a good way to simulate partial failures, and partial panel. I don't think the transponder is much of an issue (unless you're in an area where you need it, of course).

When doing a checkout, I'd say it's required to do this at least once so that one can experience the recovery in flight (can be tricky in turbulence).

-Felix

 

[TMetzinger]

There are now overlays for the G1000 PFD, that hook over the volume knobs and give you the representation of a failed component, so you can "fail" the AHRS, or the ADC, or the magnetic sensor, etc, without pulling any breakers.

 

[Teller1900]

There are now overlays for the G1000 PFD, that hook over the volume knobs and give you the representation of a failed component, so you can "fail" the AHRS, or the ADC, or the magnetic sensor, etc, without pulling any breakers.

Seems like if they're going to keep making glass for training fleets they should make an "instructor mode" that allows the instructor to fail selective portions of the display without having resort to breakers. It may not be possible at all, I've never flown glass, but it seems like a good idea to me.

 

[TMetzinger]

They looked at it for the glass Boeings too back in the day, and I believe the issue was that you didn't want to put software with "instructor" modes into a fleet airplane. Putting it in a sim is another matter. I'm sure that the Mustang sims have failure modes for the G1000. The desktop sims for the G1000 also have the ability to fail LRUs. Practicing with the desktop sim, then going out with the overlays, is supposedly pretty effective.

I don't think we'll ever see software failure simulation in flying airplanes. How'd you feel if there was a hidden "disable" switch or mode in your Beech systems?

 

[flyingcheesehead]

I've been told that pulling the circuit breaker is not the recommended way to simulate instrument failures. Among other things, I think it disables the transponder, too, depending on the plane. Check the POH and trace the electrical diagram.

Actually, Garmin's document entitled "Guidance for Designated Pilot Examiners and Certified Flight Instructors on using Garmin G1000 Equipped aircraft for Instrument Rating Training and Practical Examinations" specifically states to pull breakers, specifically the ones for the AHRS, Air Data computer, and PFD in various combinations to simulate various failures. [EDIT: OK, a newer version of the document posted here now says that the preferred method is via display dimming (page 17), but still tells how to do simulated failures via breakers (page 18) and that Cessna does not want breakers to be used to simulate failures (page 19).]

As for the transponder, it'll still work in Mode A (no altitude reporting) mode: "*Note: When the ADC is failed, pressure altitude data is no longer available to the transponder. This will result in the transponder only being capable of Mode A (no altitude reporting) capability. Therefore, failing the ADC should be avoided in Class B and C airspace or within the Mode C veil of Class B airspace, without the required coordination with the appropriate air traffic control facility. "

 

[gprellwitz]

Actually, Garmin's document entitled "Guidance for Designated Pilot Examiners and Certified Flight Instructors on using Garmin G1000 Equipped aircraft for Instrument Rating Training and Practical Examinations" specifically states to pull breakers, specifically the ones for the AHRS, Air Data computer, and PFD in various combinations to simulate various failures. [EDIT: OK, a newer version of the document posted here now says that the preferred method is via display dimming (page 17), but still tells how to do simulated failures via breakers (page 18) and that Cessna does not want breakers to be used to simulate failures (page 19).]

As for the transponder, it'll still work in Mode A (no altitude reporting) mode: "*Note: When the ADC is failed, pressure altitude data is no longer available to the transponder. This will result in the transponder only being capable of Mode A (no altitude reporting) capability. Therefore, failing the ADC should be avoided in Class B and C airspace or within the Mode C veil of Class B airspace, without the required coordination with the appropriate air traffic control facility. "

Our being largely a Cessna shop and being within the Mode C veil probably explains why I'd heard the "do not pull the circuit breaker" line. I think that the template is the best way, short of a flight training device.

I was going to say that the FTD is the best way but, while I might make that argument with steam gauges, I'm not sure it holds anymore for glass, since they provide a clear indication of failure modes, unlike the slow spindown we have with the vacuum-powered stuff.

 

[flyersfan31]

G1000 approaches are MUCH easier.

Heck, just flying in actual with a G1000 is easier. I spent over 2hrs last weekend handflying in actual in my airplane. It was a piece of cake. Spent less than 1hr handflying a Seminole yesterday with a hood on and I was sweating. Scan, scan, scan -- oops, what's that AI doing? -- scan, scan, scan -- now you want me to fiddle with radios? -- scan, scan, oops, scan.....

I flew the VOR/DME with arc into KLNS while I was doing the insurance-related dual in my airplane. Just for grins we did it with the autopilot on to see how it would work. Piece of cake. I should be so good flying an arc...

 

[poadeleted20]

so AOPA is wrong? or am I misreading this?
http://www.aopa.org/whatsnew/air_traffic/gps_in_lieu.html

"DME arcs associated with instrument approaches may be flown using GPS distance provided the DME transmitter, on which the arc is based, is identified in the GPS database (see Figure A). "

You can use a TSO C129a GPS to fly any DME arc assigned by ATC or in a published procedure except when that arc is part of the final approach segment as it is in the abovementioned VOR-DME or TACAN Z Rwy 15 approach at Martin State. This comes from AFS-410, who write the FAA's book on how to execute instrument procedures. That said, I don't know of another SIAP with a DME arc as part of the final approach segment -- every other DME arc I've ever seen on an SIAP was outside the FAF, like the Waco approach linked above, which is OK to fly per 410's guidance.

In addition, you can't ever get cleared to fly that particular approach under IFR since it interferes with both the final to the BWI 15's and departures off the BWI 33's. Nor can I imagine you'd want to fly it for real, as its minima are much higher than the GPS and LOC approaches to MTN's Rwy 15.

 

[poadeleted20]

I've been told that pulling the circuit breaker is not the recommended way to simulate instrument failures.

It's how Garmin recommends doing it. See Garmin's G1000 Guide for DPE's and CFI's which you can find on the FAA's web site as well as Garmin's. Simply turning down the left-side PFD and using the right-side unit does not meet the FAA's expectations of what is to be demonstrated on the "Failure of Primary Flight Instrument" task for IR practical tests and IPC's with G1000-equipped airplanes. They really want to flight with the AHRS failed, which is significantly more difficult. Using that overlay template mentioned by TM would be a good AMOC for pulling breakers.

 

[TMetzinger]

Oh, one other comment - on the whole "Pull the emergency switch and the DA40 is no longer IFR" issue.

It's an EMERGENCY, so you do whatever you have to do to keep the airplane under control.

This rule simply means you cannot depart on an IFR flight if the switch has been used previously and the subsequent inspection of the electrical system and batteries (and resafetying of the switch) hasn't been accomplished. There's nothing magical about the switch - it simply provides an isolation from the main buss and an emergency battery in the event you've exhausted regular battery power and still need the standby instruments.

 

[KennyFlys]

G1000 approaches are MUCH easier.

Heck, just flying in actual with a G1000 is easier. I spent over 2hrs last weekend handflying in actual in my airplane. It was a piece of cake. Spent less than 1hr handflying a Seminole yesterday with a hood on and I was sweating. Scan, scan, scan -- oops, what's that AI doing? -- scan, scan, scan -- now you want me to fiddle with radios? -- scan, scan, oops, scan.....

I flew the VOR/DME with arc into KLNS while I was doing the insurance-related dual in my airplane. Just for grins we did it with the autopilot on to see how it would work. Piece of cake. I should be so good flying an arc...

That's why I've been pushing to learn instruments on needles, first. And, definitely by hand.

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20070111X00043&key=1
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20061227X01848&key=1
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20070111X00044&key=1

These three accidents took place over Christmas weekend of 2006. During that same period, I was on a long XC where my biggest bout with IMC was while comfortably tied down at CGI. I had a bit of restricted ground contact on the return trip. But, every change was small and they as constant as necessary. I also had not only plates for the airports I stopped at, I had them for several airports along the way. In the third report, I have to wonder if he even had the plate in hand. According to a witness statement in the report, he certainly ignored the small corrections concept.

If one can fly proficiently by needles, they'll be that much better with the resource of GPS with use of a glass HSI. But, even in the G-1000, both GPS units can fail, the GPSS become inop or lose RAIM. For that reason, ya still need to know needles by nothing more than a VOR needle on that HSI.

I'm glad you're getting that experience. It will pay off someday. If there's one thing I don't want government employees doing, it's going to investigate why a fellow pilot died.

 

[KennyFlys]

It's how Garmin recommends doing it. See Garmin's G1000 Guide for DPE's and CFI's which you can find on the FAA's web site as well as Garmin's. Simply turning down the left-side PFD and using the right-side unit does not meet the FAA's expectations of what is to be demonstrated on the "Failure of Primary Flight Instrument" task for IR practical tests and IPC's with G1000-equipped airplanes. They really want to flight with the AHRS failed, which is significantly more difficult. Using that overlay template mentioned by TM would be a good AMOC for pulling breakers.

While I agree the best way to truly simulate a component is to disable it or cover it entirely as is done on analog gauges, I had recalled Garmin being not in favor of the former. Actually, it was a Cessna specific guide recommending not pulling the breakers. That was a discussion in the school at the time when I was completing instrument training.

Here is what is in Rev B of the Instrutor/DPE Guide. The same lines are in Rev A on the FAA site:

In the current book, it has this section on Page 17.

The tasks listed in this section cover flight by reference to instruments. According to the PTS,
the examiner is expected to evaluate the applicant’s use of the backup instruments with both a
full panel and a partial panel.
In the case of G1000-equipped aircraft, failures can be simulated in two ways. The preferred
method is to use the dimming controls on the G1000 System combined with selecting display
Reversionary Mode using the button on the Audio Panel. Using the dimming controls and the
Reversionary Mode is straightforward. Table 4 shows typical configurations using the display
dimming function to simulate failures.
The other, less desirable, method consists of pulling various circuit breakers. Table 5 gives​

recommendations on simulating various partial panel configurations by pulling circuit breakers.

Discussion continues on Page 19. They further site AC

Recommendations for Failure Simulation
(Cessna NAV III)​

Cessna does not recommend pulling circuit breakers as a means of simulating failures on the
Garmin G1000. Pulling circuit breakers—or using them as switches—has the potential to
weaken the circuit breaker to a point at which it may not perform its intended function. Using
circuit breakers as switches is also discouraged in Advisory Circulars 120-80, 23-17B, and
43.13-1B. Additionally, a circuit breaker may be powering other equipment (such as avionics
cooling fans), and pulling such a circuit breaker could affect the safe operation of other​

equipment.

AC 120-80 (Page 11):

c. May crewmembers use a CB as an on/off switch?

Since CBs are designed to open an electrical circuit automatically at a predetermined overload of current, they should not be used for day-to-day operational functions because they would not be performing their intended function, which is protection against overloads. Circuit breakers, even those suitable for frequent operation, should not be used as a switch to turn protected items on or off. Exceptions to this procedure should be published and included in an air carrier’s approved maintenance programs and flight operations manuals.

AC 23-17B (Page 275, First Paragraph)​

For part 23 applications, the definitions of a switch and a circuit breaker are as follows: 1) A switch is a device for opening and closing or for changing the connection of a circuit; 2) A circuit breaker is a device designed to open and close a circuit by non-automatic means and to open the circuit automatically at a predetermined overload of current, without injury to itself when properly applied within its rating. Thus, circuit breakers used for operational functions are not acceptable because they are not performing their intended function, which is protection against overloads. Circuit breakers, even those suitable for frequent operation, should not be used as a switch to perform procedural functions.​

The last reference is 8110.14.13-1B. I'm unable to find it. Ron, I'd bet you'll know where to find it. You'll also recall circuit breakers were pretty much the common means for turning systems off and on in Navy aircraft. Any time we did avionics maintenance on the ground, we would hit at least a couple dozen breakers every time. While those were another shop's responsibility, I can't recall ever having a problem with a breaker failing.​

While it seems to be ok with other manufacturers, Cessna apparently would rather it not be done and I'm betting it's a recommendation that extends from discussion with liability underwriters and lawyers.​

I do have to agree, circuit breaker are not the ideal means to train. And, if schools such as ours with a large number of students... should we ever get glass cockpits, I fear the abuse equipment and circuit breakers may suffer. As Kent said, the preferred is dimming but that's not a true partial-panel failure.​

A true partial-panel failure in a G1000 leaves a considerable number of possibilities to explore and learn how to deal with as a proficient pilot.

Cessna and other manufacturers need to find an alternate means for instructional flgiht such as altenate switching beside the CB (Matt mentioned this earlier). Or as mentioned, develop a set of overlays or blinders that can cover certain display areas on the PFD and MFD.​

My 2.75 cents-worth... ​

 

[poadeleted20]

Your points are well-taken, Ken, but if someone only trains in the G1000 by dimming one PFD and using the other, that person will be unprepared for an AHRS or ADC failure. I much prefer TM's cutout overlay to block the portion of the PFD that would be red-X'd if the AHRS or ADC failed.

 

[Teller1900]

They looked at it for the glass Boeings too back in the day, and I believe the issue was that you didn't want to put software with "instructor" modes into a fleet airplane. Putting it in a sim is another matter. I'm sure that the Mustang sims have failure modes for the G1000. The desktop sims for the G1000 also have the ability to fail LRUs. Practicing with the desktop sim, then going out with the overlays, is supposedly pretty effective.

I don't think we'll ever see software failure simulation in flying airplanes. How'd you feel if there was a hidden "disable" switch or mode in your Beech systems?

In a way we do. The power switches for the EFIS tubes and DPUs are on the CA's side of the pedestal panel. The reversionary controls can essentially "fail" one side's EFIS displays. The "VG Fast Errect" button will cause a temporary data failure on that side...looks the same as if an AC Bus were to fail. Doesn't bother me any. We know what all those things do and we don't use them unless we have to.

From what I hear, though, the VG Fast Errect was a great way to simulate a DPU failure in the days before sims. It kills the AHARS for a few seconds while it cages the vertical gyro. It doesn't hurt anything or have side effects like pulling the DPU breaker can (power surge can easily fry the delicate inner-bits of the DPUs) or shutting the AC Buses/inverters (lose half the engine instruments, TCAS/TSPDR, both AHARS, etc), and it fixes itself in 40-50 seconds if the pilot doesn't do a X-Data Tsfr or DPU Tsfr in a timely manner.

I say this fully admitting that I know NOTHING about how the G1000 works, but why isn't it feasible to have a button that kills the attitude reference or heading reference gyro and puts that beautiful red X across the screen? Or if nothing else, just superimposes the X on working gauges? If people don't want it on their personal Skyhawks, make it an option that flight school can have to stop wearing out their breakers. I realize I'm probably oversimplifying this, but I'm genuinely curious.

On a side note, 3-M makes those static cling things for laptops that limit the viewable angle...why not have the same thing for the G-1000 (but have it black out a straight-on view instead of an off center view)?

 

[KennyFlys]

Your points are well-taken, Ken, but if someone only trains in the G1000 by dimming one PFD and using the other, that person will be unprepared for an AHRS or ADC failure. I much prefer TM's cutout overlay to block the portion of the PFD that would be red-X'd if the AHRS or ADC failed.

Actually, I agree with you. I guess I wasn't clear on that one. My final observation is there needs to be an alternate means of cutting power; perhaps an option installed only on a training aircraft. Or, possibly an STC that allows use of the breakers for training but with a mandate for the breakers to be replaced during the annual inspection.

But, the cheaper means would be an overlay that will stand up to the abuse of repeated use and not require one to put their fingerprints all over the screens.

 

[gismo]

The last reference is 8110.14.13-1B. I'm unable to find it. Ron, I'd bet you'll know where to find it. You'll also recall circuit breakers were pretty much the common means for turning systems off and on in Navy aircraft. Any time we did avionics maintenance on the ground, we would hit at least a couple dozen breakers every time. While those were another shop's responsibility, I can't recall ever having a problem with a breaker failing.​

​

Klixon breakers are rated for 5000 cycles and AFaIK this applies whether the action is electrically (overload) or mechanically (used as a switch) triggered. The datasheet say what level of reliability this is related to but typically this means that there's a 99.9% chance that any CB will survive that many operations.

Based on that it seems unlikely to me that the occasional use of a CB for disabling the AHRS would significantly shorten the life of a CB but I suppose that in an airplane used almost exclusively for instrument training it could become an issue. Ironically, Klixon's toggle breakers which are initended to be used as a switch, the rating is the same 5000 cycles.

 

[poadeleted20]

Given the FAA's refusal to allow cutout switches for the vacuum system to provide realistic vacuum system failure training in flight, I don't see them allowing the same for the ADC or AHRS in the G1000 or Avidyne. Good thing that Frasca, et alia, make nice G1000 and Avidyne panel simulators and FTD's where you can see nearly for real, although it is unfortunate that those machines are so expensive it's hard to find one in which to train. Until then, we'll have to settle for the hang-on templates to cover the significant portions of the PFD just as we rely on suction cups for the AI and HI.