I think that the questions depend on the type of training, modular or integrated, and the course your looking for. Some general questions may be:
- number and type of aircrafts in fleet
- aircraft's equipment
- number of flight instructors
- "type" of flight instructors, full time or part-time hired.
- instructor's availability
- number of students enrolled
- Time taken to complete the training
- Avg time required after finishing the training to take the skill test (in my case, I'm waiting to take the ppl skill test since May!)
- Ground school total hours, in case of modular ask for time and day of lessons
- Total cost of the course, always ask for hidden cost like training material such as books, plotters, charts, additional landing fees. Check if the skill test is included as well as the theory and written test.
- Ask on what type of aircraft you will be flying and if you can switch or try other types during your training.
- Ask if they're open all days of the week. My school is closed on monday and thuesday. I didn't ask, so I didn't know when I started
- if maintenance is done by the school personnel or by other staff locally based. From experience I've seen that schools doing their maintenance on other airports from where they are based take a longer time to have their aircrafts back in fleet after maintenance done, and if this school as a few planes they may be all out of service and you could be unable to fly for maybe a week or even more...
That's it. If I'll have other question then I will add them to this post.