Sprey claims that the glue, made of classified chemicals, emits toxic gasses when the jet is travelling at Mach 1.6 (around 1,200 miles), contrary to the U.S. Air Force’s claim that the Raptor’s operating speeds on high altitudes might be the cause of the problem. Apparently the glue has to be constantly re-applied to the jet’s “stealth coating” during maintenance, thereby increasing the risk of the pilots.
Diisocyanates, which are found within the polyurethane glues that comprise the stealth coatings, can reportedly cause both severe lung and neurological problems. Sprey added that the Air Force has overlooked the problem because it it could find the toxins in the blood of the pilots. Also, he claims that the Air Force doesn’t want to look into the problem because it requires rebuilding the expensive jet.