RV-7A - Weight & Balance concerns. Is it the right plane for us?

jrs14855 said:

The new format for ops limitations require only Vso, Vx, Vy and the weight and cg where these numbers were obtained. There is a paragraph about "throughout the normal operating speed range" or words to that effect, which would IMPLY testing to Vne, among other things.

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The problem I have is the above post where you say that only Vso, Vx, Vy and the weight and cg where these numbers were obtained need to be tested. This is simply not true because of the statement in paragraph (38) stating that you certify that the aircraft is controllable throughout it's normal range of speeds and throughout all maneuvers to be executed.

The operating limitations come directly from FAA Order 8130.2H and it IS regulatory.

You can finish this conversation alone. Have a nice day.

Mel said:

The problem I have is the above post where you say that only Vso, Vx, Vy and the weight and cg where these numbers were obtained need to be tested. This is simply not true because of the statement in paragraph (38) stating that you certify that the aircraft is controllable throughout it's normal range of speeds and throughout all maneuvers to be executed. [...]

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I lost a bit track of the disagreement between you and jrs14855, it appears however that you are talking past each other.

He stated, as a response to my (apparently false) assumption regarding the testing of stall speeds, that Vso, Vx, Vy are the only numbers which need to be determined during flight testing, while he also clarified that the plane must still be operated throughout all speeds and maneuvers.

Again, please excuse my ignorance, but I believe that you both are saying the same thing...

Testing

Normal range of speeds is a rather arbitrary requirement. My interpretation is the most wide ranging, that normal range of speeds should include testing from Vso to Vne and the entire range in between. Were it a one off design it the standard protocol is a dive test to 110% of Vne.
One question is whether each example of such a well proven design as the various Vans aircraft need to be tested to Vne. One option for those intimidated by Vne testing is to simply placard a reduced Vne, which could easily be changed by subsequent owners simply by placing the airplane in phase 1 for a short time and retesting.
My airplane is not a Vans. Based on a personal conversation with the designer I am comfortable routinely operating the airplane at Vne in smooth air. This is also influenced by several examples of the design that have been routinely operated 25% above the recommended Vne. Also on the fact that the designer set Vne on his personal airplane 25 m/h above the Vne shown on the plans. My airplane on a standard day at 75% power is right at the "standard" Vne and the power has to be way back for even a slight descent.
Just an aside, apples to oranges, but turbine powered airplanes are normally operated at Vne in descent, even in light turbulence. Aircraft originally certified with turbine power have a green arc on the airspeed all the way to Vne. These aircraft are designed and tested to a slightly higher "gust loading" requirement than typical piston powered light aircraft. The comments on turbine aircraft apply only to lower altitudes where mach limits do not apply. In many cases at high altitude it is not practical to operate at the mach limit. However some of the new generation corporate jets cruise at the mach limit.

N941WR said:

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One other thing, the -7 and -9 do share the same fuselage, with minor differences for the spar.

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For the archives, I'll also point out the seat and seat ribs are slightly different as well. There may be some more subtle differences in structural elements but I haven't compared them enough. Nominal exterior dimensions are identical of course