Specific ground attack aircraft like A-10 and Su-25 have titanium 'bathtub' shells to protect pilots. Development of surface-to-air and air-to-air missiles made armor obsolete in modern fighter jets.

However, in 1960, a U-2 flown by CIA pilot Francis Powers was shot down by the USSR’s SA-2 surface-to-air missile (SAM ... flying at such fast speeds, titanium was selected as a material ...