An extremely important part of BOTH pilots duty is to listen to, correctly hear, and respond to radio calls. Even if you're not the pilot on the radios and are just sitting there, how do you know that your other pilot just heard that radio call correctly? How do you verify, when acting upon the ATC instruction, that you're doing the right thing if you can't guarantee both of you heard the correct instruction? All it takes is ONE incorrect interpretation, one incorrectly heard number, etc to get a violation on your record. Pilot deviations are hard enough to avoid when you're doing things right, much more when you've got an Ipod playing into your headset.
As a potential pilot of the other aircraft you're about to have a mid-air with because you have to listen to Green Day while in cruise, I'd like to ask you stop doing this. I'm sure your passengers would appreciate it too...
And for those of you who do it secretly so that the other crew member does not know you're doing it, you can know that for sure if I fly with you and catch you doing it, I'll be making a call to pro standards the second we land. I'm not going to put my career or safety in the jeopardy because of your unprofessionalism.
uke:
