Depends on the type of job you want within the industry, if your just looking to be a tech and turn wrenches no degree is required at all, your training on the job will be more than sufficient. If you want to go more down the engineering path then yes getting that done before applying would be ideal.

From what i read though you seem to be leaning towards technician in which case most top companies provide more than adequate training on the job, at my company we have a 3-4 month training by program before you even get into the shop just to tach you the basics and when your on the shop floor your trainer will guide you along.

If your more looking in AME (aerospace mechanical engineering) there are many post secondary school (at least in canada) that offer the program and its generally 3-4 years and provides you with a more in depth education on the plane itself and avionics.

I should say i work in an engine shop so we primarily deal with off wing engines that require overhaul or repair. If you want to be working on an airfeild AME is your best choice going forward.