Lost my HSI (G1000) in IMC yesterday

[Tim]

I flew the one hour flights to/from Raleigh Durham in IMC yesterday and got some X-ing out of the HSI on several occasions. Each time it was while I was being vectored to the LOC in the clag.

Each time the HSI came back after a (seemingly endless) short delay, 10-30 seconds. Of course, it confused the trusty KAP140.

Has anyone else seen something like this in the air? Did you get it fixed? How did you fix it? It's got me wary of instrument approaches in hard IMC. Thanks. Tim

[Rick]

Tim,

Just to clarify - there was a big red X across the entire HSI, not just the HDG setting like we sometimes get during runup? I'm sure you must have had your hands full, but did you notice anything else X-ed out at the same time, or just the HSI? Any alarms about h/w failures, etc?

I will check the G1000 Maintenance Log and see if anything was recorded when this happened.

[Chris]

I flew the one hour flights to/from Raleigh Durham in IMC yesterday and got some X-ing out of the HSI on several occasions. Each time it was while I was being vectored to the LOC in the clag.

Each time the HSI came back after a (seemingly endless) short delay, 10-30 seconds. Of course, it confused the trusty KAP140.

Has anyone else seen something like this in the air? Did you get it fixed? How did you fix it? It's got me wary of instrument approaches in hard IMC. Thanks. Tim

Our plane is at the avionics shop today for this exact issue. It has only happened a couple of times in the air, and never in IMC for us. The belief is that it just needs to be recalibrated, but they are also checking to see if a ferrous bolt was accidentally swapped with a non-ferrous bolt the last time the magnetometer was removed.

I'll update once I know the results of today's service.

[Tim]

Tim,

Just to clarify - there was a big red X across the entire HSI, not just the HDG setting like we sometimes get during runup? I'm sure you must have had your hands full, but did you notice anything else X-ed out at the same time, or just the HSI? Any alarms about h/w failures, etc?

I will check the G1000 Maintenance Log and see if anything was recorded when this happened.

The HDG bug was X'd out and the points of the compass disappeared. The Localiser remained, as did the glide slope but the LOC was in the 12 & 6 positions as on a clock face.

[Fred]

Tim,

Just to clarify - there was a big red X across the entire HSI, not just the HDG setting like we sometimes get during runup? I'm sure you must have had your hands full, but did you notice anything else X-ed out at the same time, or just the HSI? Any alarms about h/w failures, etc?

I will check the G1000 Maintenance Log and see if anything was recorded when this happened.

The HDG bug was X'd out and the points of the compass disappeared. The Localiser remained, as did the glide slope but the LOC was in the 12 & 6 positions as on a clock face.

Somthing as simple as the OAT sensor will red x your AHRS. I had this issue and the av guy told me a times its the AHRS LRU, and somtimes it just a matter of reloading the flight computer software which dispays all the sensor data on the PFD.

[Tim]

I wonder if those are things that can be done in flight, while on approach?

[Rick]

I wonder if those are things that can be done in flight, while on approach?

Which things? Reloading the software, or recalibrating the magnetometer? I would recommend AGAINST trying either of those in flight!

[Tim]

I wonder if those are things that can be done in flight, while on approach?

Which things? Reloading the software, or recalibrating the magnetometer? I would recommend AGAINST trying either of those in flight!

... somtimes it just a matter of reloading the flight computer software which dispays all the sensor data on the PFD.

I was wondering if that meant a reboot of the system, which could perhaps be done in flight but perhaps it means reloading from the SD card, which obviously can't. Sorry if it's a stupid question, just exploring the options.

[Rick]

I wonder if those are things that can be done in flight, while on approach?

Which things? Reloading the software, or recalibrating the magnetometer? I would recommend AGAINST trying either of those in flight!

... somtimes it just a matter of reloading the flight computer software which dispays all the sensor data on the PFD.

I was wondering if that meant a reboot of the system, which could perhaps be done in flight but perhaps it means reloading from the SD card, which obviously can't. Sorry if it's a stupid question, just exploring the options.

I'm sorry, Tim - I wasn't trying to imply anything. I had just read the other thread about updating to V22, and had that in my mind (obviously something nobody would/could try on approach). It's too early in the morning for me to try to make humor. I withdraw my post!

[Fred]

I wonder if those are things that can be done in flight, while on approach?

Which things? Reloading the software, or recalibrating the magnetometer? I would recommend AGAINST trying either of those in flight!

... somtimes it just a matter of reloading the flight computer software which dispays all the sensor data on the PFD.

I was wondering if that meant a reboot of the system, which could perhaps be done in flight but perhaps it means reloading from the SD card, which obviously can't. Sorry if it's a stupid question, just exploring the options.

Tim, the flight computer software installed with the G1000 is the brains of the the senor data being collected. Your NAV (Loc and ILS) work fine becuase thankfully they are direct measurements from the radios and not the flight computer.

ANY problem with the AHRS, Moving MAP, or AutoPilot are based on the data recieved from the flight computer. The flight computer determines if the inputs are with-in tolerance; if not, red x the instrument. If your X's only occured with the AP engauged on approach I would check your OAT sensor; the temp is one of the vaules used when on AP among other things.

When I had my similar issue the G1000 certified tech said is was likey the flight computer software got corrupt, or the AHRS LRU really was out of spec. Since they more or less troubleshoot and do warrenty work they swapped out the AHRS LRU and reinstalled the flight computer software.

Fred