Work experience is an asset. As you have mentioned that you have not interest in the field you studied, you have to choose some other filed in which you have an interest.
But to get a job you should have a basic academic qualification they need or the relevant work experience.
The details like when you graduated, where you are employed now and what is your age now are not available in the question. So a specific answer is not possible. We can give general suggestion.
If you like aviation and have experience then choose the same for your further career. However if you are on a job now, think twice to quit. Quit only on getting a better job. You may also try to get more update education by joining some relevant courses in the field of your interest.
But it will be easier for you to stick to those field somehow connected with your basic course(mechanical engineering). You can choose jobs related to sales, marketing, supervisory and management in the connected area.
You can also try jobs in openings where the needed qualification is any graduation, like banking, general administration etc if age criteria permits. In aviation also there may be similar sections and departments where you can join.
Take a proper decision considering your age, how much years passed after you graduated and at what level you are now placed, what is your situation in family and personal life.