AVIONICS SMOKE is detected in the outflow(exhaust flow), so it is more difficult to tell which radio/computer is being fried, but it may not put smoke into the cockpit, as it is only being detected in the avionics exhaust flow.
I hope this isn't a stupid question, and I realize that it may be unaswerable in any specific sense--how long might one expect between the initial smoke message, and the point at which shutting off the electrical supply wouldn't help? In other words, how much time does a crew have to consider the possibilities and react before a fire would become self sustaining?
Makes one wonder if all non-aircraft runway operations should include a bulldozer among the equipment - to ensure the runway can be cleared on three minutes notice.
I know this aspect of the incident hasn't had much discussion, but if anyone is interested, I can comment about the performance of a milling machine such as the one involved here. Among those of us who play in the dirt rather than the sky, the consensus of opinion is that to try and take it directly into the grass would probably have resulted in it getting stuck before it was far enough off for the runway to be considered "clear". (Unlike much construction equipment, they're not intended to be run off-pavement.) Also, with a top speed in the neighborhood of 10 mph, 3 minutes wouldn't be a unreasonable expectation to reach the nearest taxiway.