A 3 years research project regarding early damage detection and reparation on aircraft's has finished on April 2008. At the end of the study aerospace engineers at Bristol University, with funding from the Engineering and Physical Sciences Research Council (EPSRC) came up with an idea which will make aircraft's safer and lighter.

The self-repairing technique is based on a simple principal: the aircraft has a vascular network, somehow similar to the circulatory systems of human beings, so when a bruise of crack in the body of the airplane appears, the resin compose inside the artificial vessels will bleed out, repairing the crack.
This technology could repair a crack even during flight, but is not meant to replace conventional controls and repairs. In fact, by mixing the resin with dye, those cracks are easier to see during a ground inspection, and if necessary further repairing measures will be taken.

The new technology will also result in lighter airplanes, which means fuel savings, reduced carbon emissions and lower costs for airlines and passengers. The self-repairing planes will be available for commercial use in about 4 years.