[Wing] Consumer satisfaction?

[Rob Prior]

George McNutt wrote:
>     individuals who seem to think that their MD-RA training manual
>     supercedes the CAR's.

Hi George,

I'd be interested in knowing which parts of the training manual 
supercede which CAR's.

>     (1) Gross weight increase,
 >
>     This
>     seemed to be a case of the MD-RA worrying about their own liability
>     and ignoring what the CAR's said about the subject.

According to the calculation in Appendix A of Chapter 549 of the CAR's, 
the maximum permissible wing loading of an RV-6A (using dimensions from 
Van's website) is about 16.5 lb/ft^2, corresponding to a gross weight of 
about 1800lb.  That exceeds Van's reccommended numbers by 200 lb and 2 
lb/ft^2.  Do you feel qualified to second guess the designer, even if 
"everyone else is doing it"?

Remember, the CAR's are meant to be generic, they weren't written 
specifically for RV's.  They list the *limits*.  They don't list what is 
reasonable or prudent for any one design (or for any one specific, 
modified, aircraft).  Only the designer can be doing that.

Frankly, i'm surprised Van's was ever willing to write letters 
authorizing increased gross weights at all.  Do those letters come with 
reduced G limits?  They should...

-RB4