IFR with a VFR GPS

Steven P. McNicoll wrote:

Primary navigation (the VFR GPS) is no longer reliable, the aircraft is
IMC, and the pilot is unaware that the unit is no longer reliable. Those
are not properties of a problem?

I don't think so. If the aircraft drifts off course the controller will
nudge it back and the pilot will then be aware that the unit is no longer
reliable. No problem.

The controller's attention might be elsewhere (have you never been sent
right through a localizer?). That said, my Garmin 196 does warn me
when it loses reliable reception, though it's not proper RAIM.


All the best,


David

wrote in message
oups.com...

The controller's attention might be elsewhere (have you never been sent
right through a localizer?).


There's no similarity. There's a window of a few seconds for the turn to
intercept the localizer. It would take at least several minutes for the
controller to notice an enroute aircraft drifting off course unless the GPS
was erroneously calling for a significant turn. If it did that the pilot
should notice the error before the controller.

The controller's attention might be elsewhere (have you never been sent
right through a localizer?). That said, my Garmin 196 does warn me
when it loses reliable reception, though it's not proper RAIM.

Reliable reception is not equivalent to integrity. You can have great
reception and one bad signal that drives your position off hundreds of
miles. And yes it is rare (10E-5/hour). BUt aviation integrity is at
the 10E-7 rate.

Ron Lee