Ops Limits and Maneuvering Speed
Gregg,
I've put the Van's recommended limits in the transition training manual (Part 3). There is also an extensive discussion of maneuvering speed, which isn't a fixed value, as well as how to compute Va for your airplane via flight test. There is also discussion regarding Vne (which is not an IAS) as well. A link is available on the safety page. As a rule of thumb, 4G's will keep you honest regarding limits whether applied symmetrically (straight pull) or asymmetrically (rolling pull) if you operate within designer's weight and balance limits and the airplane has been properly constructed and maintained IAW the plans. Both Va and Vne can be misunderstood and merit a bit of study to understand what they mean and how to apply them in real life--if you are already aware, than please disregard!
The weight and balance limits for the -4 may be found on Van's web site on the worksheets provided for that purpose. Maximum recommended gross weight is 1375 lbs. and the aft CG limit is 27.5% chord for aerobatic flight. The positive symmetric G limit at or below this weight is 6.0. Van's does not specify asymmetric G limits, however FAR 23 certification requirements specify an asymmetric limit of at least 66% (i.e., 3.96G's), so this is where the 4G rule of thumb comes from. Since Van's types are all-metal, they are susceptible to fatigue damage from over-stress, but due to their excellent handling characteristics, 3-4 G's is generally plenty for aerobatic work. If you operate at weights above design specifications, you are your own engineer and test pilot (which, in EAB is allowable if that is your intent and IAW the Operating Limitations).
Vne for the -4 is 210 MPH. Vno is 180 MPH.
If you don't already have a copy, the preview plans have a builder's manual with quite a bit of good information that can be helpful as well.
Cheers,
Vac
