IMHO no they are not safe.

My guns travel as luggage ( in pelcan type case or tuffpak ) 4-6 times per year. ( Hungary, South America, Georgia and Oregon)

The cases come off the planes pretty well scuffed up. I can not imagine a small Negrini, Browning or Americase faring well.

You will likely pick them up from baggage claim scratched, scuffed and dented. Hopefully the firearms inside will travel well.

With the Pelican case or TuffPak there is no question.