[ChiefPilot]

The question of whether or not fuel should be included when calculating gross weight for aerobatic purposes has been discussed several times. It usually goes something along the lines of "I have a letter from Van who said ..." or "Van's has approved ..." etc. but rarely is there any evidence of such a claim.

Fortunately, Van's Aircraft has taken an official position on this in a service letter: http://vansaircraft.com/pdf/letters/ServiceLetter-2015-11-20.pdf

From the service letter:

Bottom Line:
The weight of the fuel, whether it is in a wing tank or a fuselage tank, must be included in the aerobatic gross weight of all RVs.

 

[Saville]

That's that.

Makes perfect sense to me.

 

[Brantel]

Finally some official statement on the subject.