Originally Posted by
Fursty Ferret
I really think that if you're fitting one of these you should go back to step one and think about how you're recording clearances while in the aircraft.
Easy for those of us flying Airbus etc - we just dial the new clearance straight into the FCU. Or we use the MCDU scratch pad. And we also have a PM who can write clearances on the PLOG, and we even have tables to write on!
If you are single pilot, hand flying a basic machine, it is not so easy.
The snag with the thumbwheel type of device is that it can take up to five presses to select each new digit - ideally you need to be able to press the exact numbers first time. I would still go for two basic calculators mounted somewhere to record headings and altitudes.
Think about the visibility of the displays in the dark and check if they power save - they could turn off at an inopportune moment !