Praise be to Allah.
If your turning a blind eye to excess baggage is done with the knowledge and permission of the company, and the company considers it as a means of attracting passengers, then there is nothing wrong with it. But if it is an individual effort on your part and is done without their knowledge and permission, then you should not do it, because it is not up to you to turn a blind eye with regard to the rights of others. (This response was read to Shaykh Muhammad al-‘Uthaymeen and he agreed with it).
With regard to inexpensive promotional gifts, such as diaries, calendars, coasters and so on, that carry company names and logos and are distributed as a form of advertising, if they are given to everyone and not just to you, then you can take them.
But if they are given only to you or they are very valuable, then you should not take them if they are given to you, because this is a kind of bribe. You have a regular salary from the company which you take in return for your efforts, so do not take anything from anyone else for your work. This also applies to anything else that is in the nature of a valuable gift, such as reductions. You should not accept these, and you should buy from people who do not know you. The guideline in this matter should be: if you were in a different position and were not working for this airline company, or you were a student, for example, or without work, would they still give you this gift or reduction, or not? On this basis you will know whether to accept what is offered to you. And Allaah knows best.