yes. but if you have done your transition training you prep for PFD/MFD failure and consequences. You have a backup 3 pack, 2 garmin 430’s, and an autopilot with which you could shoot a non-precision GPS approach.
Yes, once you have identified the source of the failure and isolated it. Until then you are sitting with the Masters off looking at dark screens and listening to your gyro spin down. It is important to have a plan B for that scenario.
I have a backup E-gyro with which I have practiced keeping the oily side down. But even in its absence, I believe I could kill the masters, identify and pull all essential bus breakers except the backup AI, and repower the essential bus before the backup gyro spins down. But I have practiced that sequence and keep my circuit breaker diagram in my kneeboard.
yes. but if you have done your transition training you prep for PFD/MFD failure and consequences. You have a backup 3 pack, 2 garmin 430’s, and an autopilot with which you could shoot a non-precision GPS approach.
Actually, with the PFD failed in IMC, you MUST declare an immediate emergency and land as soon as possible, and the approach itself is an emergency procedure. If you are in VMC when the failure occurs, you must remain in VMC and may not enter IMC in order to land unless you declare an emergency first.
Of course you ask – WHY? Well, according to the FAA’s GPS navigator certification standards, the 430 / 420 Garmins ARE NOT IFR CERTIFIED WITHOUT AN EXTERNAL CDI INDICATOR installed and operational. The HSI (or EHSI) and the second nav head in a six-pack plane provide independent redundancy for CDI information, but in PFD-equipped planes, THERE IS NO BACK-UP. Both “nav head” CDI pointers are contained in the PFD. When it goes T/U, you are no longer flying an IFR-certified aircraft and must act accordingly. You MAY NOT LEGALLY FLY a GPS approach in IMC and / or under IFR using the tape strip CDI on the navigator screen for course guidance. (Of course, you can’t fly any kind of navaid-based approach either, since the internal tape-strip CDI isn’t coupled to the NAV radio in any way.) Your only recourse is to declare the emergency and terminate the flight under the blanket authority covering in-flight emergencies contained in FAR 91.3.
BTW, there are many reasons for the prohibition on using the tape-strip CDI, two of which are:(1) lack of sensitivity / full-scale deflection resolution of the pointer and (2) no course guidance failure annunciation. (Interestingly, the Garmin 480 IS IFR-certified w’out an external nav head, since UPSAT originally had it certified using the more stringent WAAS TSO and provided an internal CDI display that meets the certification requirements, something Garmin has yet to do with the 420/ 430/ 530. Maybe the WAAS upgrade will include this capability…)
William:
Not exactly true. Your batteries will last a while but when you are turning eveything off you have to trn them off as well. Your AI is electrically driven and you will lose it in about 2 minutes if you have no juice. In IMC that is a big problem.
Brian,
What I was getting at was replacing the Cirrus S/B horizon with a certified horizon with an integral battery which lasts for around an hour…these are available right now.