A masters in liberal arts may be what you want. You'll still be driving a truck after you graduate, but you may advance to driving a taxi or even a limousine. You have work experience and you have a degree. It makes you an ideal candidate for an MBA program. Take the GMAT, and if you get a decent score there are hundreds of programs that will accept you. Your age does not matter. You'll be taking classes with many people younger and older than you. A good full time program will take two academic years. Part-time can take 3-4 but you can continue working. There are accelerated programs that take less time.
Explore the Official MBA Guide. It's a comprehensive free public service with more than 2,000 MBA programs listed worldwide. It allows you to search for programs by location (US, Europe, Far East, etc.), by concentration (finance, marketing, aviation management, health management, accounting, etc.), by type of program (full-time, distance learning, part-time, executive, and accelerated), and by listing your own criteria and preferences to get a list of universities that satisfy your needs. Schools report their accreditation status, tuition cost, number of students, class sizes, program length, and a lot of other data. Schools provide data on entrance requirements, program costs, program characteristics, joint degrees, and much more. You can use the Guide to contact schools of your choice, examine their data, visit their web site, and send them pre applications. You can see lists of top 40 schools ranked by starting salaries of graduates, GMAT scores, and other criteria.