A friend called the other day to say that he knew of someone who had received a violation for not having a current VOR check as required by FAR 91.171. Incase you’re a little foggy, that’s the reg for VOR equipment check in IFR operations. To quote:
“(a) No person may operate a civil aircraft under IFR using the VOR system of radio navigation unless the VOR equipment of that aircraft—
(1) Is maintained, checked, and inspected under an approved procedure; or
(2) Has been operationally checked within the preceding 30 days, and was found to be within the limits of the permissible indicated bearing error set forth in paragraph (b) or (c) of this section.”
Now suppose that the aircraft in question is equipped with a WAAS-approved GPS unit? Since WAAS units are approved for sole source IFR navigation, as long as you do not use the VOR function of the WAAS receiver or another VOR radio, a check shouldn’t technically be required. That said, we highly recommend that you make the check anyway and please log it somewhere.
If you are using the VOR function of the WAAS receiver or any non-WAAS GPS unit (which is not approved for sole navigation under IFR) the check is required.
The check doesn’t count unless it is logged but the reg doesn’t specify where it has to be logged or that it has to be carried board the aircraft. But, if asked, you will need to be able to send it to the FAA inspector if requested.
Might be time to update this rule. I wonder if the guidance to FAA inspectors is keeping pace with technology?
Stalls at Altitude – Part II
Comments regarding Air France 447 continue to dominate the news and blogosphere. Thanks to all who commented on this blog. I am reminded of a few observations by Captain Bob Buck, who wrote the classic book, Weather Flying. He noted that attempting to top a thunderstorm was not smart as the aircraft would likely be close to its operational ceiling. One good bump could precipitate a stall. There will be much discussion on what the pilots saw or didn’t. It is perplexing to me why one would climb in those circumstances. The investigation will tell us more.
Finally, those of us who fly glass cockpit aircraft should be thinking about how to handle such aberrations when the infallible magic fails. Obviously, it happens.