when I started working as a flight attendant i was a bit worried about the scar i have on my hand. it goes ocer the whole top of the hand and is about 10cm in length. At that time it was quite visible as it was a bit red.
I covered it with camouflage make up (for example
http://www.apresmakeup.com/faq.asp). The one I used was a creamy paste that was "dusted off" with powder to make it waterproof. it really wored well.
Hope this is the information you were looking for
enjoy your job as a flight attendant
Christina