AHRS consist of magnetometers, microelectromechanical systems (MEMS) accelerometers, and MEMS gyroscopes on all three axes. They are no CPU based, have no RAM or disk…they are not software driven.
The G1000 panels are CPU base but the firmware in them is a decade old. When you do your monthly updates you are not changing the basic operating system or the firmware you are updating sectionals, plates and other reference material than changes on a monthly basis.
These systems are not IOS or Windows based systems. They are embedded…they do not get a ‘software crash.’
Hmmm… a very basic misunderstanding of hardware and software. Nowadays even an AHRS module will contain a processor (with software running on it 
) to implement stuff like temperature compensation, and of course the comms interface.
And while you could have a device such as say a G1000 working perfectly for 10 years, it is completely possible for a new database to crash it, by exposing something which was in there all along but never got exercised. This issue is common as muck, as they say…
Peter wrote:
And while you could have a device such as say a G1000 working perfectly for 10 years, it is completely possible for a new database to crash it, by exposing something which was in there all along but never got exercised. This issue is common as muck, as they say…
Also, you do update the firmware from time to time. (Or you should, anyway.)
The glass versus steam gauges debate is endless, not just here but on all aviation boards. The big jets to do not fly with steam’s. Why? If glass was not reliable it would not get certification. If glass was prone to breakdown the big commercials would not be using those panels. And they are setup with redundancy, unlike steams.
The G1000 and it’s non-certified peers (Dynon & G3x) are in many ways more sophisticated than the glass in 20 year old passenger jets. But taken together once you fly with a glass panel you will never want to fly with steams again…..
Anything will break at one point. Glass cockpits, spaceships, computers, your fridge at home … I wonder why that is so hard to accept.
From my own experience I would lean towards thinking that an all electric airplane (like my SR22) is generally a bit more reliable than vacuum pumps. Maybe it’s because I had three vaccump pumps fail on me in the past, once in IMC (in my IFR training). But i have no statistics to prove it, and probably they don’t exist.
It is critical to understand that with any of our airplanes there can be a critical and dangerous failure in the systems. That’s why we practice flying on the backup instruments and why we should develop strategies to deal with eve the most critical failures.
If glass was not reliable it would not get certification. If glass was prone to breakdown the big commercials would not be using those panels
Isn’t that a bit easy? Airliners have different budgets (for money AND for room for multiple sets AND for electrical power AND for crew training, the pilots being professionals). In G/A criteria are quite different.
Also, it is not a black/white discussion of reliable/unreliable. Every machine, each gimmick, has a certain degree of dependability. Some better, some worse.
Jan_Olieslagers wrote:
Airliners have different budgets
And the gear has to meet higher standards.
Commercial jets are using the SAME glass as the G1000. The major difference is for multi-jet engine management. Again, these systems are far more reliable given the redundancy of dual panels, dual AHRS, and dual radios. And many even bother to duplicate GPS nav on a tablet as a backup to the backups.
USFlyer wrote:
Commercial jets are using the SAME glass as the G1000.
What’s that supposed to mean?
Again, these systems are far more reliable given the redundancy of dual panels, dual AHRS, and dual radios.
You can have dual radios, GPSs, AIs, etc. Even without an integrated suite. Triple or quadruple, really, if you want.
And many even bother to duplicate GPS nav on a tablet as a backup to the backups.
Yes, because integration is limiting your options and there are failure modes that impact a lot more gear than with separate boxes. Having something completely independent is nice. If glass is so dependable, why are there standby instruments? GPS is simply a matter of preference as they’re everywhere these days, even dedicated units are affordable and quite a lot of people prefer them to paper maps as a backup.
USFlyer wrote:
AHRS consist of magnetometers, microelectromechanical systems (MEMS) accelerometers, and MEMS gyroscopes on all three axes. They are no CPU based, have no RAM or disk…they are not software driven.
This is incorrect. They definitely contain software, and microprocessors. These are used for filtering and combinging data from severial sensor to one single output.
USFlyer wrote:
The G1000 panels are CPU base but the firmware in them is a decade old. When you do your monthly updates you are not changing the basic operating system or the firmware you are updating sectionals, plates and other reference material than changes on a monthly basis.
As an owner you are not allowed to do firmware updates. Dealers can do firmware updates, and these are quite common, an all modern avionics.
USFlyer wrote:They are embedded…they do not get a ‘software crash.’
Being embedded doesn’t mean the software can’t crash. They do have the advantage that the hardware interface are often known.
AHRS/ADHRS are embedded devices part electronics (discrete device chips) and part mechanical (gyros etc). They do not have a general CPU, RAM, disk. The firmware is chip based and not updated by anyone except the manufacturer. That would require removal of the device and shipment back to the factory…
The PFD/MFD on the other hand are CPU based and do have solid state disks, local networking, and store updates made via USB or SD cards which contain charts, plates, bug fixes, and feature adds.
