NOVELTY - Primary flight structure comprises a load bearing composite shell defining at least the exterior of a helicopter fuselage, the fuselage defining at least a central fuselage section and tail boom, where the central fuselage section is adapted enclose at least one of an engine or drive train.    USE - The primary flight structure and methods are useful for forming helicopter fuselage having at least center section and tail boom section; building helicopter; and for joining two surfaces of a flight structure (all claimed).    ADVANTAGE - The process or method provides advantages such as accurate shape reproduction when such items are to be produced. The accurate reproduction of item shapes provides the advantage of being able to replace items on the fuselage without requiring any specific attention to the fitment of that item. Accurate fitment allows manufacturing cost and time to be greatly reduced.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are:    (1) an enclosure adapted to provide protection for one or more fuel cells, the enclosure comprising at least four upstanding panel members spanning between an upper and lower internal surface of a substantially enclosed composite fuselage or outer shell of a flight structure, at least two panel members having a surface extending laterally relative to the interior of the fuselage or outer shell of the flight structure interior and attaching to the internal surface of the fuselage at least in an upper and lower region thereof, and at least two panel members extending longitudinally to the interior of the fuselage or outer shell of a flight structure interior and attaching to the interior surface of the fuselage at least in an upper and lower region thereof, the panel members defining an enclosed space;    (2) a method of forming a helicopter fuselage having at least a center section and tail boom section, comprising providing at least two molds, a first molds having an inner shape substantially corresponding to a port section of a desired outer fuselage shell profile and a second mold having an inner shape substantially corresponding to a starboard section of a desired outer fuselage shell profile, applying fabric layers into each of the first and second mold to form a port fuselage section and a starboard fuselage section, and infusing a resin into the layers of fabric to create a composite structure;    (3) a method of building a helicopter comprising providing a fuselage outer skin or shell, the shell comprising at least a fuselage center section and tail boom, the fuselage outer skin or shell delineating openings and defining a substantially enclosed space, and inserting members into the fuselage through at least one of the openings;    (4) a crashworthy seat assembly for an aircraft comprising a seat base component, the seat base having a lower surface adapted to attach to the aircraft, and a seat pan component where the seat pan is adapted to attach to the top of the seat base, the seat component formed of a composite laminate structure;    (5) a fastening providing a mechanical and chemical attachment between at least a first and second opposing surface, each of the surfaces having holes extending from an opposing side to a non opposing side, the fastening comprising an adhesive layer located between the first and second surface and extending through at least some of the holes, the adhesive layer having a head located on each non opposing side of the first and second surface;    (6) a method of joining two surfaces of a flight structure comprising providing at least two opposing surfaces of a flight structure to be joined, providing holes in each surface that extend from an opposing side to a non opposing side, providing a layer of adhesive between the opposing surfaces, where the adhesive is of a type that chemically or mechanically bonds to the surfaces, the adhesive being of a liquid form or at least paste, positioning the surfaces together such that the adhesive flows or is otherwise forced through at least some of the holes from the opposing side to a non opposing side, and the adhesive forming a head on the non opposing side, and curing the adhesive; and    (7) an aircraft surface with an appendage attached by a fastening mechanism providing a mechanical and chemical attachment between the aircraft surface and appendage, the mechanism comprising a mechanical and chemical attachment between at least a first and second opposing surface, each of the surfaces having holes extending from an opposing side of each of the aircraft surface and appendage to a non opposing side, comprising an adhesive layer located between the first and second surface and extending through at least some of the holes, the adhesive layer, when cured, having a head located on each non opposing side of the aircraft surface and appendage surface.