The FBI is investigating a rash of sexual assaults on airplanes in the last year. The feds don’t keep statistics on how common this crime is, and say most cases go unreported. The feds say most sexual assaults on airplanes happen on longer, nighttime flights, when the cabin is dark and many passengers are dozing off. On a Honolulu-to-LAX flight, a state lawmaker from Hawaii unzipped a woman’s pants while she was sleeping, and rubbed her crotch, according to court records. The FBI says passengers should immediately report all crimes that occur on airplanes, and that they also provide victim support services.