.. do let me flesh out John's reply just a tad to make it a bit easier for you ..
(a)
FAR 23
(b)
AC 23-8 gives a lot of explanatory material for flight test activities in respect of FAR 23.
It's very important to read the relevant ACs to get a feel for what the Americans intend in their regulations.
Also, keep in mind that, for a given aircraft, one must read the relevant version of the regs .. the regs are a living document but the certification standard for a given Type usually is frozen in time ...