- Engine limitations
For an O-320 with a Sensenich 74-DM-56 prop the redline is 2700rpm.
Approved spin recovery drill
There's basically nothing in my own POH about this (or anything much else either), although it does say the entry speed for spins is the stall speed! I've also looked in the Univair POH for the PA18-150 and it doesn't mention spins, although spins are approved in the utility category.
I've never spun mine.
- Flap limiting speed
85mph = 74 knots in the Normal Category
Incredibly, the Vne is 133 knots, which is almost unimaginable. Also, it looks like you can solo it from front or rear seats, not that I fancy the latter.
If you want more in the way of answers, I'd post the question over in the Cafe Supercub discussion folder at
www.supercub.org. You'll find very little information in the POH which is notoriously sketchy -- just a few speeds and limitations really. I suppose at least that means nothing is forbidden!
QDM