Impact resistant aircraft leading edge structures and aircraft including the same
Aircraft empennage structures have impact resistance satisfying transport aircraft certification requirements (for example, FAR part 25 and/or other international certification requirements). The structures may be specifically embodied in leading edge structures that are preferably in the form of one-piece components formed from fiber-reinforced composite materials (e.g., reinforcement fibers such as glass fibers, aramid fibers and/or carbon fibers embedded in a polymeric matrix such as an epoxy resin). The leading edge structures will most preferably include an arcuate skin and longitudinally extending internal reinforcement which is generally Y-shaped and includes a planar rib element and a pair of planar divergent reinforcement arms. The rib element may be positioned so as to be coplanar with a longitudinal bisecting plane of the leading edge structure. A forward end of the rib element may thus be integrally attached aft of an apical end of the skin, whereas an aft end of the rib may be integrally attached to each of the reinforcement arms. According to certain embodiments, rigidity and thus impact resistance may be facilitated by providing the apical end of the skin with a greater cross-sectional thickness as compared to the attachment ends of the skin.
1. An impact-resistant aircraft leading edge structure comprising:
an arcuate skin and a longitudinally extending internal reinforcement integrated together as a one-piece component formed of a fiber-reinforced composite material, wherein
the skin has an apical end and a pair of attachment ends, and wherein the apical end has a greater cross-sectional thickness as compared to the attachment ends; and wherein
the longitudinally extending internal reinforcement includes a planar rib element and a pair of planar divergent reinforcement arms, wherein forward sections of the reinforcement arms have a greater cross-sectional thickness as compared to aft sections thereof.
2. An impact-resistant aircraft leading edge structure as in claim 1 , wherein the fiber-reinforced composite material includes one or more types of reinforcement fibers selected from the group consisting of glass fibers, aramid fibers and carbon fibers.
3. An impact-resistant aircraft leading edge structure as in claim 1 , wherein the fiber-reinforced composite material includes glass fibers embedded in an epoxy resin.
4. An impact-resistant aircraft leading edge structure as in claim 1 , wherein the composite material is electrically non-conductive.
5. An impact resistant aircraft leading edge structure as in claim 1 , wherein a forward end of the rib element is integrally attached aft of the apical end of the skin, and wherein an aft end of the rib element is integrally attached to each of the reinforcement arms.
6. An impact-resistant aircraft leading edge structure as in claim 1 or 5 , wherein the rib element is positioned so as to be coplanar with a longitudinal bisecting plane of the leading edge structure.
7. An aircraft leading edge structure comprising:
an arcuate skin having an apical end and a pair of attachment ends, wherein the apical end has a greater cross-sectional thickness as compared to the attachment ends; and
a generally Y-shaped longitudinally extending internal reinforcement integrally attached to the skin, wherein
the longitudinally extending internal reinforcement includes a planar rib element and a pair of planar divergent reinforcement arms, wherein forward sections of the reinforcement arms have a greater cross-sectional thickness as compared to aft sections thereof.
8. An aircraft leading edge structure as in claim 7 , wherein the skin and the Y-shaped internal reinforcement are formed as a one-piece component from a fiber-reinforced composite material which includes one or more types of reinforcement fibers selected from the group consisting of glass fibers, aramid fibers and carbon fibers.
9. An aircraft leading edge structure as in claim 7 which is formed as a one-piece component from a fiber-reinforced composite material.
10. An aircraft leading edge structure as in claim 9 , wherein the composite material is electrically non-conductive.
11. An aircraft leading edge structure as in claim 7 , wherein a forward end of the rib element is integrally attached aft of the apical end of the skin, and wherein an aft end of the rib element is integrally attached to each of the reinforcement arms.
12. An aircraft leading edge structure as in claim 7 or 11 , wherein the rib element is positioned so as to be coplanar with a longitudinal bisecting plane of the leading edge structure.
13. An aircraft leading edge structure as in claim 1 or 7 which has impact resistance according to requirements of Part 25 FAR and/or other international transport aircraft certification requirements.
14. An aircraft which includes at least one aircraft leading edge structure according to claim 1 or 7 .
15. A method of providing impact resistance to an aircraft, comprising installing on a leading edge of the aircraft a leading edge structure as in claim 1 or 7 .