Originally Posted by
CVG_DL
I travel weekly on KLM and the occasional trip back to the US on Delta and AF.
Yes, it's definitely too big for KLM. The "56 cm" you're looking at is 56 x 45 x 25 cm. It's that extra 10 cm depth (45 vs. 35) which is going to be too big for KLM.
(Just to note that the 55 x 40 x 20 case is actually going to be too large for KLM. They quote a limit of 55 x 35 x 25 cm, so you're 5 cm too large in one dimension, but giving up 5cm in the other.)
I don't know how strict KLM & Delta are with hand baggage.