My favorite cat that traveled so well in his crate disappeared and I rescued a cat at the shelter = less than one year old but not really a kitten. She hates the crate and howls I have seen some...
Feliway, a sheet over the crate, l-tryptophan, rescue remedy, are all readily available and things I have found useful for calming kitties down. There are probably others, but I would start with those.
You might also start reconditioning kitty with respect to the crate. Ztart by feeding in front of it, then just inside, all the way inside, inside with door closed... You can create a calmer association with being in a crate, which will help with travel.