In general, the operational life of a civil aircraft ranges from twenty to thirty years depending on operational demand and profitability. A few World War II C47s
Figure 15.37. Anti-icing subsystem using boots
(b) RJ family rain-repellent system
(Courtesy of BAE Systems)
Figure 15.41. Civil aircraft turnaround servicing locations
(Dakota) are still flying. Thousands of aircraft already have been grounded and thousands more will be grounded forever in the immediate future. Their storage occupies much land and aircraft disposal is not the same as for automobiles. The disposal of older aircraft is a serious problem.
Metal sold as scrap can be recycled but increasing amounts of composite material are accumulating. Disposal of composite materials is difficult because they serve no useful purpose as scrap – attempts are being made to make them recyclable. Avionics black boxes and microprocessors contain toxic materials; the fluids in display units also are toxic. It is expensive to rid the environment of toxic materials. Incineration plants are specifically designed to keep the efflux clean.
More research is continuing to find suitable materials that are less toxic and also can cost effectively be disposed of. This is a concern of material scientists; however, aircraft designers must stay current with materials technology and make proper selections.