NeilMcLeod said:
I've done the 40 hours met the requirements for the log book endorsement but my flight test continues. I'm surprised that there isn't more dicussion about flight test and flight characteristics especially at the edges of the envolope.
Yeah, a full flight test program takes a lot more than 40 hours. I am continually amazed at the folks who talk about "flying off the 25 hours". I wonder how well they know the edges of their aircraft's envelope, and how many things they do the first time with a passenger on board.
You are right, there is hardly any discussion in this part of the forum at all. But I'm happy to talk flight testing all day long. I am starting a trip back home today, and won't get there until Friday PM, so I'll only have internet access at a couple of times in that period.
NeilMcLeod said:
For one, how are people doing testing at gross weight and aft cg. I put 100 lbs of sand in the baggage and 100 lbs in the passenger seat which was as much as I was comfortable strapping in. That gets me 60 lbs shy of gross with full fuel but nowhere near aft. Less fuel moves the cg aft but not much. For practical flight test purposes I can't get much further aft than 85 in. (aft limit 86.82) With 5 gals of fuel and a 369 lb passenger (!?) I can almost get to aft cg and gross wt.
Van's recommended weight/CG envelope is big, to try to offer a useable envelope no matter which engine and prop you have. It looks like you have no need to clear the envelope all the way back to 86.82". Figure out what aft limit you need and stop there. Change your POH to show that as your aft limit. If the heavy weight/aft CG part of the envelope is not useable in your aircraft, then you can draw a weight/CG envelope that has an angled line at the top right corner, and only worry about testing to the edges of that envelope.
Do you have a way to tie down the ballast in your baggage compartment?
NeilMcLeod said:
What surprised me was how much different the plane flew with a relatively aft cg and near gross wt.. It's true that it flys much nicer light but also it is nicer at mid to slightly foreward cg. I'm not sure I'd like it at all at the aft limit. I like the way the plane flys for the most part but not everthing is perfect. For example with the new big rudder and fin on the 7 I think the rudder pedal forces are very high, too high for my liking any way.
The stick forces in pitch will get lighter as the CG moves aft. That is, you'll need less stick force to produce a given manoeuvre in pitch, and the aircraft will become quite sensitive. It won't trim at a desired speed as nicely, as a tiny bit of stick force will move it off the trimmed speed. Is this the sort of thing you were noticing, or did you spot some other characteristic?
At aft CG the stalls might be a bit sharper, and more forward stick might be needed for recovery. The spin characteristics may be worse too.