On Jan 2, 10:10*am, J a c k wrote:

...the best course of action involves doing the right pilot-thing NOW,
declaring an emergency as soon as possible, and filing an ASRS report
promptly after the flight.

I would add a few points to amplify this basically sound logic:

1) Fly the airplane
2) Fly the airplane
3) Fly the airplane

If you need to go into controlled airspace without permission to
prevent destruction of your airplane and yourself, do not hesitate. Do
what you need to do to get back to a safe flying condition. If you get
back down bellow 18k promptly it might make sense to call ATC, but I'm
not sure what real purpose it serves other than meeting some FAR on
reporting youself appropriately and that need might be better served
through some other means than a radio call. Secondly, I'm not sure why
you'd hang out above 18k long enough to make the call before decending
via spoilers, but I guess it could happen. I think I'd be too busy
flying the airplane.

The airmanship point bears repeating in this case and in general.
Whenever you are flying near a limit (controlled airspace, Vne, severe
weather, terrain!) you need to exercise extra caution and presume that
conditions outside your control (lift, sink, gusts) could conspire
against you in the least favorable possible ways. I have seen many
people fly under these circumstances assuming that those conditions
will remain within (or close to) the ranges they have personally
experienced - I think it is prudent to assume something much less
favorable and keep margins appropriate to those assumptions. This
applies as much to assumptions about expected sink on final glide and
it does to assumptions about lift near 18,000'. One needs to be very
cautious about watching climb rate when above 17,000', particularly if
carrying any significant energy in the form of airspeed.

9B