RK,
You might look at section 10 of the General Control Line rules. Depending on the competition event, a maximum width is listed. In my old rulebook, there is no category limiting the width for stunt. So then the question becomes is there a PAMPA Profile Stunt requirement? Or, in the case of local contests, is there a club rule set for profile stunt?
As examples, our club, the Valley Circle Burners limit the fuselage width to 3/4" including doublers.
3) Airplane: Any profile airplane is allowed.
a) The engine may be mounted in any configuration side-mounted, upright or inverted.
b) Doublers or triplers and cheek cowls are allowed, including faired spinners, but the fuselage must meet the “profile” definition of ¾” thickness by the trailing edge of the wing/flap hinge line
and the engine must be fully exposed from lugs to plug.
We have waived the fully exposed requirement in the case of nose rings, such as on the Brodak Oriental, in the past. We need to decide whether we want to make this a permanent rule change.
However, intentionally burying the engine seems to me to defeat the definition of a profile, and does not meet the fully exposed requirement. Of course, these requirements would only apply if you
were to enter it into a competition. For a sport plane, build it however it best satisfies your needs.
For another, the Northwest Sport Profile also limits you to 3/4" fuse width.
http://flyinglines.org/rules.profilestunt.htmlI have not seen any restrictions about the internal construction method. Based on a review of the rules, profile refers to external shape and dimensions, not whether it is a plank or built-up.
Whatever you decide, I hope you enjoy your project!
Dave
PS--I would have checked the current AMA rulebook, but their new improved website freezes up after I get in and start navigating. On the other hand, I can wander around in the members section magazine archives all day long...