John Clonts wrote:

FWIW, you can put the new card in the KLN-94 before the effective date.
The old data will be used until the
effective date. If you are using it at 0000 UTC on the effective date
(6pm CST) it will give you a message,
telling you to power off and back on to use the new data.

Which, IMO, stinks.

I was flying a night, IFR flight over Washington, DC, airspace, being
guided by GPS and the autopilot. Before you point it out: Yes, I got
caught with my pants down. I didn't have a current VOR tuned as a backup.

Upon acknowledging this message and rebooting the GPS, the GPS would not
lock onto the required number of satellites, so suddenly the GPS was an
overpriced paperweight.

I switched the AP to HDG mode, quickly reached for my charts, identified my
position on the chart, then tuned and twisted the navigable VOR station,
but not before I drifted about a mile east of course. Once the VOR was up,
I was able to get back on course and continue.

The GPS finally came back on line about 5 minutes after the episode
started. Needless to say I learned a very healthy lesson that night.

--
Peter