172 g1000 (AHRS) (comm) problem

eric_ocean

eric_ocean

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osprey1
i have been newly checked out in a 172 sp g1000, i love the airplane....having learned in a low wing aircraft....the 172sp made it alot of fun....with the new caricteristics....
but the one thing is after just a few flights the attitude (ahrs)on the PFD, goes out on me...during the climb out....comes back on during the level flight...but lost again on base to final....and the comm went out aswell....has anyone else seen a problem like this?.....
also...i just cant believe there isnt a ball on the standby attitude (not to mencheon the location isnt the best)...its a great system i just think it could be i bit different...for me anyways...

PS...id also like to know how long the standby batt. would last in a alt. malfunction....i know it say 30 mins....but that sure seems to be a push...for such a demanding system on power.
 
eric_ocean said:
i have been newly checked out in a 172 sp g1000, i love the airplane....having learned in a low wing aircraft....the 172sp made it alot of fun....with the new caricteristics....
but the one thing is after just a few flights the attitude (ahrs)on the PFD, goes out on me...during the climb out....comes back on during the level flight...but lost again on base to final....and the comm went out aswell....has anyone else seen a problem like this?.....
also...i just cant believe there isnt a ball on the standby attitude (not to mencheon the location isnt the best)...its a great system i just think it could be i bit different...for me anyways...

PS...id also like to know how long the standby batt. would last in a alt. malfunction....i know it say 30 mins....but that sure seems to be a push...for such a demanding system on power.
Click to expand...

Have you tried switching the PFD info to the MFD (push the red button) to see if you have the same problem there?
I've never experienced what you said but we did have a comm problem once on Comm 2 (only on the PFD) and that turned out to be an issue in the software update.

As for the standby batteries, they seem to last just as long as the POH says. At least the times we've tested it.
 
yes sir....was the first thing i tried, was switching....no luck
 
Garmin and Cessna has been addressing complaints of the AHRS shutting down or rebooting. Last I heard, they can't reproduce it but their suspicion is it may be caused by cell phones left on.
 
KennyFlys said:
Garmin and Cessna has been addressing complaints of the AHRS shutting down or rebooting. Last I heard, they can't reproduce it but their suspicion is it may be caused by cell phones left on.
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I would be embarrassed as a company to even try to make a claim such as that.
 
jesse said:
I would be embarrassed as a company to even try to make a claim such as that.
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Your lack of faith is disturbing (said in his best James Earl Jones voice).

EMC (or in this case, a lack of EMC) is very much a potential issue. You're supposed to turn off all PEDs until they've been proven benign in your aircraft. And the FCC insists that your cell phone be off when airborne.

Cell phones may or may not be the problem, but I wouldn't rule them out just because it might be embarrassing.

Oh, and I AM an EMC engineer. I don't play one on TV, nor did I stay at a Holiday Inn Express last night.
 
Ghery said:
EMC (or in this case, a lack of EMC) is very much a potential issue. You're supposed to turn off all PEDs until they've been proven benign in your aircraft. And the FCC insists that your cell phone be off when airborne.
Click to expand...

I wholeheartedly agree that it could be the phone... After hearing the amount of noise my phone gives off in the car stereo, especially when it's about to ring... And it also will almost completely disable my trackpad if held in close proximity, and do all kinds of other crazy stuff to other electronics around it.

Maybe I should start shutting it off in flight.

FWIW, I haven't seen any problems with the 430W in flight with the phone on. :no:
 
Ghery said:
Your lack of faith is disturbing (said in his best James Earl Jones voice).

EMC (or in this case, a lack of EMC) is very much a potential issue. You're supposed to turn off all PEDs until they've been proven benign in your aircraft. And the FCC insists that your cell phone be off when airborne.

Cell phones may or may not be the problem, but I wouldn't rule them out just because it might be embarrassing.

Oh, and I AM an EMC engineer. I don't play one on TV, nor did I stay at a Holiday Inn Express last night.
Click to expand...

It's not that I'm saying it's impossible that the cell phone caused it. I'm saying that I would be embarrased to have to say that my technology or product was so sensitive. I would be embarrased to say that my products of which my customers put their life in--could fail and reboot over a simple cell phone.

Forget your cell phone on and have the G1000 freak out as you smack into the side of a mountain confused. The only acceptable thing to say here is -- Fix it Garmin.

"Turn your cell phone off" is not an acceptable solution when you are talking about human error and the addition of passengers.
 
Then you don't understand how small the signal strength of GPS is, and the compromises manufactures have to make to produce products that are functional and yet don't weigh too much or cost too much or...

If a person is too stupid to turn off a device that he KNOWS radiates a significant amount of energy (when a digiphone switches to analog, for instance), then that person is too stupid to be a PIC. Aviation is all about attention to detail, and as we saw in another thread on here, one little thing can quickly become two little things, and then snowball.

Like Ghery, I'm an engineer with a lot of experience in this stuff. And I AM staying in a Holiday Inn Express.... so that makes me twice as right!:rofl:
 
TMetzinger said:
Then you don't understand how small the signal strength of GPS is, and the compromises manufactures have to make to produce products that are functional and yet don't weigh too much or cost too much or...

If a person is too stupid to turn off a device that he KNOWS radiates a significant amount of energy (when a digiphone switches to analog, for instance), then that person is too stupid to be a PIC. Aviation is all about attention to detail, and as we saw in another thread on here, one little thing can quickly become two little things, and then snowball.

Like Ghery, I'm an engineer with a lot of experience in this stuff. And I AM staying in a Holiday Inn Express.... so that makes me twice as right!:rofl:
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There is a huge difference between a cell phone causing GPS interference and the entire Garmin G1000 rebooting. The first sucks, but is acceptable. The second is not acceptable at all.
 
In the G1000, the AHRS gets data from the GPS, as well as the magnetometer and the Air Data Computer. Depending on what is and isn't available, you get different modes of degradation. That's the reason there's a standby gyro and a compass.

Not that it makes it any less irritating, but it should be an irritant to lose the PFD, not a life threatening emergency - you've still got an AI, altimeter, airspeed indicator and a compass.
 
Ghery said:
Your lack of faith is disturbing (said in his best James Earl Jones voice).

EMC (or in this case, a lack of EMC) is very much a potential issue. You're supposed to turn off all PEDs until they've been proven benign in your aircraft. And the FCC insists that your cell phone be off when airborne.

Cell phones may or may not be the problem, but I wouldn't rule them out just because it might be embarrassing.

Oh, and I AM an EMC engineer. I don't play one on TV, nor did I stay at a Holiday Inn Express last night.
Click to expand...

But it is still a chintsy answer. Since cellphone use at least three different air interfaces (2 are TDMA and one is CDMA), power levels below .6 Watts, and I would *THINK*, having had done a bunch of EMC testing myself, that when Garmin tested these things they would have been zapping them with common interefers at power levels higher than what is seen in the cockpit.

I dunno, that excuse sounds like a big SWAG to me.
 
my cell phone was certainly off...and thru the checklist i called "cell phones off"...but did not confirm that my passanger had turned theirs off....this was a mistake on my part...one i didnt even realize, till now!
 
I have had that problem too. My cell phone was off. I took off, went IMC, AHRS problem, was flying by the compass, and somehow, it fixed itself after about 5 minutes.
I asked a CFI about it, and he seemed to think that maybe I didn't turn something on in the proper order. It could be possible...I do boneheadedly seem to skip a thing or two in the written checklists from time to time.
 
I also agree that any attempt to attribute the failure of the AHRS and PFD to cellphone signal (or any other EMI short of a full-blown, nuclear-weapon EMP) is utterly unacceptable.

Every time I fly in to the Dallas area from the southwest, I fly right over the "antenna farm" at Cedar Hill, and the RFI there is strong enough to break the squelch on every radio in the airplane, and often, to make communications with Approach controllers difficult. I am confident that the signal levels there, at the aircraft's antenna, are vastly in excess of what any cell phone puts out. The signal level from the cellphone, at the airplane's antenna, cannot be much; and if the cellphone's signal is entering the system's electronics anywhere other than the antenna and are there causing trouble, the machine is either broken in some important way, or profoundly inadequate in its RFI shielding.

Losing the GPS signal is one thing - but having actual system shutdown for functions which require no signal external to the airplane whatsoever is "whole 'nother."


If the cellphone signal (or any other normal electronic device emission) is truly the cause of the AHRS and/or PFD failure, then the system in simply not airworthy and should be re-engineered. If not, they need to stop making excuses and trouble-shoot the beast.

I personally believe that, if cellphone signals could cause the PFD to fail, we would have heard a LOT more about it by now. It was me, I'd consider that aircraft day VFR only, until they find a cause and implement a fix.
 
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Just wondering... I guess FAR 91.21 doesn't matter at all? Sure, it does not apply to Part 61 VFR, but still? I'm sure it was written for a reason.
 
flyingcheesehead said:
I wholeheartedly agree that it could be the phone... After hearing the amount of noise my phone gives off in the car stereo, especially when it's about to ring... And it also will almost completely disable my trackpad if held in close proximity, and do all kinds of other crazy stuff to other electronics around it.

Maybe I should start shutting it off in flight.

FWIW, I haven't seen any problems with the 430W in flight with the phone on. :no:
Click to expand...

Blackberries are the worst for this... we can always tell, on a conference call, when somebody with a Blackberry starts sending or receiving a message. Buzzing and modem-type sounds on the line.
 
flyingcheesehead said:
I wholeheartedly agree that it could be the phone... After hearing the amount of noise my phone gives off in the car stereo, especially when it's about to ring... And it also will almost completely disable my trackpad if held in close proximity, and do all kinds of other crazy stuff to other electronics around it.

Maybe I should start shutting it off in flight.

FWIW, I haven't seen any problems with the 430W in flight with the phone on. :no:
Click to expand...

Blackberries are the worst for this... we can always tell, on a conference call, when somebody with a Blackberry starts sending or receiving a message. Buzzing and modem-type sounds on the line.
 
I have a few hundred hours behind the G1000, the only time I had a failure to date was in IMC at 1:00am in the morning. I lost all vacuum pump, real fun. It was interesting, we'd spent so much time worrying about training for a G1000 failure, I had to think about what happens if the standby fails first.

As far as the AHRS, I think it's largely a function of it tumbling. I will say that over the years, the G1000 with it's regular software updates has added valuable features, and become a even more stable. I've not experience the AHRS deficiency in the climb thought, that is unacceptable. Aircraft needs to go to Mx.
 
HIGHwing said:
I have a few hundred hours behind the G1000, the only time I had a failure to date was in IMC at 1:00am in the morning. I lost all vacuum pump, real fun.
Click to expand...

Uhhh... So you had a *standby* failure, not a G1000 failure then, right? G1000 doesn't run off vacuum. Cessna, in their infinite wisdom :dunno: decided to put a vacuum pump in for the standby instruments, rather than the electrical that everyone else uses.

Hmmm... Which is lighter and/or cheaper, a second alternator (which would provide backup for the G1000 as well as the round gauges), or a vacuum pump?
 
flyingcheesehead said:
Uhhh... So you had a *standby* failure, not a G1000 failure then, right? G1000 doesn't run off vacuum. Cessna, in their infinite wisdom :dunno: decided to put a vacuum pump in for the standby instruments, rather than the electrical that everyone else uses.
Click to expand...
That's what the battery is for. A guaranteed thirty-minute battery life should be enough to get anyone down. I'm sure it would last much longer but I've not seen anything published.

Hmmm... Which is lighter and/or cheaper, a second alternator (which would provide backup for the G1000 as well as the round gauges), or a vacuum pump?
Click to expand...
Let's go with a vacuum pump.

Saturday, I got the pleasure of left seat in a Columbia 400. It has a full G-1000 suite including the integrated autopilot. I've not heard of any issues with the system in that bird and none were known by the rep.

This was the same plane Neal Boortz flew during his last book tour. The 400 is a pretty sharp plane. And, the tail is on straight! :)
 
I took a new 182 to the FlyBQ with the G1000/GFC700 setup. Very nice, and the VNAV worked as advertised. Given a choice between an ILS or an LPV in the future, I will take the LPV if minimums are comparable - no "waviness", just a solid approach all the way down.

The Columbias have the alpha keypad for the G1000, which is a step in the right direction. I look for a small alpha keypad with a small display for flight plan input and modification, much like the FMC on jets. Because the G1000 is modular this will probably not be too hard to implement.
 
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