What next, you ask? Well, how about an airplane that fixes itself! Science fiction, the fourth dimension or reality? Modern aircraft are increasingly using composite materials in their construction, and these composites have some unusual characteristics. For example, over time they will develop small cracks or tiny holes. Researchers are developing a resin that "bleeds" when damaged or under stress, which forms a scab over the hole or crack, effectively repairing itself. Dr. Bond (Ian, not James!) says "We're also developing systems where the healing agent isn't contained in individual glass fibres but actually moves around as part of a fully integrated vascular network, just like the circulatory systems found in animals and plants. Such a system could have its healing agent refilled or replaced and could repeatedly heal a structure throughout its lifetime. Furthermore, it offers potential for developing other biological-type functions in man-made structures, such as controlling temperature or distributing energy sources." The composite material is made from hollow fibers which are filled with epoxy resin, so when a hole or crack appears, the resin leaks out and seals the break returning it to 80 or 90 percent of its original strength. The epoxy is colored, making it easy for mechanics to spot the repairs and make a permanent fix once the aircraft returns to base. Imagine a fighter aircraft damaged in a dog fight repairing the bullet holes from the enemy aircraft and returning to base already repaired! So truth may be stranger than fiction. Until next time keep your wings straight and level Hersch! JetAviator7 ps: Don't forget to sign up for our newsletter "All Things Aviation" here!