Ask HN: As an engineer, how do I interview a manager?

I'm working as a software developer at a startup, and it's been decided that we need a couple managers. As a technical lead, I'm one of the first to go when interviewing those who may end up being my manager.

I only really feel capable of judging fit: can I work with this person, would he fit personality-wise with the company, etc. What are some questions I should ask and areas to cover to try to determine if I think he'd be a good manager?