On the Eaglesoft Beechjet overhead panel, one of the deice switches is labled INSTAS. It's not described in the manual and google turned up nothing. Anybody know what that is?Also, there is an annunciator labled AHRS BAT. It's not described in the manual either. Anyone know what it is?thanks

AHRS BAT would most likely be a warning that the the attitude heading reference system is using battery power only. Your attitude and heading instruments are on limited power supply.

Thanks. I learned something new.

I'm still trying to figure out what Deice INSTAS means. Is it like an emergency instant deice system?

Instrument Air System.

>Instrument Air System.ok. I'm googling for that, but not getting much that is helpful. Can you elaborate a bit? thanks.

I guessed, it may not be correct -It means the deice for the system providing outside air to your flight instruments - The altimeter, vertical-speed indicator, and airspeed indicator. On a light airplane, this would be called pitot heat. On some airplanes, the static port(s) are also heated.If you also have seperate pitot heat switches, I'm wrong.

There are seperate pitot and static heat systems. But INSTAS does sound like it's an acronym for instrument air system, so I do think you're on to something.There was a guy over on the eaglesoft forum who said he had time in a beechjet. I asked this question of him several days ago but he hasn't answered.Oh well, I'll just keep researching.