g600 4 red x’s

[benyflyguy]

Friend has a g600. Notes about 2-3 months ago when started getting 4 red X’s usually a min or two into climb out. Only happens intermittently. Also only happens when plane parked outside on hot day for several hours.
4 red x’s Are airspeed, vertical speed, altitude and OAT.
Will get intermittent red X’s and then once over 12k it fixes itself.
Did happen on ground once as well.
One guy said might be because probes are on the side of aircraft (not bottom) and air temp probe is getting too hot??
Plan is to replace the air data computer but now wondering if probe placement has anything to do with it??? Or needs to be addressed??

 

[Dan Thomas]

Many instrumentation problems are due to loose or dirty or oily or wet connectors. In a glass cockpit there are plenty of connections to check before buying expensive components.

 

[benyflyguy]

Many instrumentation problems are due to loose or dirty or oily or wet connectors. In a glass cockpit there are plenty of connections to check before buying expensive components.

Thanks. everything was pulled out. Checked connectors and reseated everything.

 

[Ryan Klems]

Garmin's general advice for the GTP 59 probe is "kept away from heat sources, e.g. exhaust, engine cowlings, cabin exhaust valves, direct sunlight, etc." So that might not be the absolute best location, but not that bad, and if it was really an issue, I'd expect it to have been an issue all along. I wouldn't expect the OAT probe failure/erroneous data to take out all of the air data functions, really only TAS and such, and things that rely on it like wind display. It more sounds like the GDC is failing, losing power, data bus connection or something to that effect. What error messages are they getting?

 

[benyflyguy]

Garmin's general advice for the GTP 59 probe is "kept away from heat sources, e.g. exhaust, engine cowlings, cabin exhaust valves, direct sunlight, etc." So that might not be the absolute best location, but not that bad, and if it was really an issue, I'd expect it to have been an issue all along. I wouldn't expect the OAT probe failure/erroneous data to take out all of the air data functions, really only TAS and such, and things that rely on it like wind display. It more sounds like the GDC is failing, losing power, data bus connection or something to that effect. What error messages are they getting?

Just the 4 red Xs. No message

 

[jsstevens]

3 of the four are dependent on the static port. I have no idea if that helps, but it jumped out at me from the list.

 

[WannFly]

what he said, pitot-static leak?

 

[mondtster]

It has been my experience that even if the G500/600 system has a pitot or static system leak it will not produce any red Xs. The symptoms will be similar to those found in systems containing the old mechanical gauges.

I also have my doubts that this is related to the OAT sensor. I'd agree with the troubleshooting that has already been done, my area of focus would be on the air data computer.