Display of Radio Call Sign (Registration Number) in Cockpit

What regulation requires the display of the radio call sign (aircraft registration number) in clear view of the pilot?

ANSWER: There is no regulation that requires the call sign or registration number to be displayed in the cockpit. It has become an industry standard to do this so the pilot can recall the number as necessary.

If you wish, you can create a placard with the call sign or registration number and afix it to the panel in view of the crew.