Assuming you are not using my AddonV1-for-Osprey-Rel2 (so: use the standard MV22B-Rel2 package as-is) and use the default key commands for hoist operation (like Ctrl-U, J , and K ):
The only difference between the default FSX-Accel EH101, and the MV22B-Rel2 is, that in the MV22B you explicitely need to open the Hoist door first.
In the EH101 this is implicite (the hoist door opens automatically when you type "Ctrl-U")
So what you need to do in the MV22B:
1. Open the Hoist (bottom) door, by mousewheeling the Hook selectorknob in the overhead panel, to the ON position.
2. Type "Cntl-U" to extend the Hoist arm; this take appr. 10 sec (== fixed time in FSX-Accel).
3. Then Type "J" to arm the cable (in Spotplane view, you will see a short cable appear underneath the MV22B)
4. Type another "J" to lower the cable. Now you should see the red message text "Sling Hook Enabled" in your screen.
5. Type another "J" (or "K") to stop the cable
6. Type a "K" to raise the cable; if the cable is fully raised, the text message "Sling Hook Enabled" should disappear.
Steps 2-6 should work exactly the same as in the default FSX-Accel EH101.
If it doesn't: where does it go wrong ??
Rob