A typical metal spar in a general aviation aircraft usually consists of a sheet aluminium spar web , with " L " or " T " - shaped spar caps being welded or riveted to the top and bottom of the sheet to prevent buckling under applied loads . Larger aircraft using this method of spar construction may have the spar caps sealed to provide integral fuel tanks . Fatigue of metal wing spars has been an identified causal factor in aviation accidents , especially in older aircraft as was the case with Chalk 's Ocean Airways Flight 101
Chalk 's Ocean Airways Flight 101
Chalk's Ocean Airways Flight 101
Spar (aeronautics)