B siyata d’shemaya, just had a class on Hillul Hashem. Definition giuven by the Rav –
H H = If people see someone who learned Torah and they think his behavior did not become more refined or, worse, became worse. Then, they project these behaviors on Torah. So, all you need to ask – how would someone who sees my actions think about them?
example from Chulin – R Pinchas b’ Yair forces the river to let him cross because he is on the way to a great(est) mitzva – pidyon shevuyim (while river claims it is also doing ratzon Hashem and does it right!). He then tells the river to let the next Jew to pass because he is carrying wheat for matzah (a less urgent mitzva). Then, he also tells river to pass for an Arab businessman who joined them on the trip. Gemora’s conclusion – miracle akin to splitting the sea is performed so that a non-Jew will not say that Jews abandoned him on the trip. So, be considerate to other people on a plane, that’s all I am saying.