Scan Frequency

[Jaybird180]

During cruise flight in IMC (and in the freezing zone) how long should it take to perform a complete scan inside and outside the aircraft? Is there such thing as too fast? Too slow?

Does the scan time vary during phases of flight? Perhaps eliminating something from the scan to increase frequency on remaining items (intentional fixation)?

Why in my reading (unless I missed it) in the FAA pubs is the mag compass not part of the 6-pack scan? Isn't it useful for detecting a failed DG? Is it unnecessary because you presume the probability of vacuum failure and simultaneous electric TC failure is infinitessimally small?

 

[wabower]

If you fly in conditions that might result in airframe icing, an easily visible OAT probe or other similar shaped device (in my case the AOA probe) can be your best friend since ice will form and be more visible and easier to gauge than on larger surfaces like wing leading edges. On twins, the tips of the prop spinners are a good tell-tale.

My routine is to start the cruise portion of each flight with a thorough check of all systems and indicators, then set one of the on-board timers for 20-minute count-down. When it beeps I check everything again, including precession, and continue on the same interval for the remainder of the trip. For the 19+ minutes between the checks I just do the normal stuff to FTFA.