I liked that scene in Dumbkirk where the stricken and out of fuel RAF airplane flies for miles and miles with a dead engine due to no fuel. Such realism. Such authenticity. Those airplanes are made of iron and steel and they do not glide. They flounder, they go nose down and they crash.
Also not authentic that there was anything "heroic" about Dunkirk. Had Hitler not been a complete moron, and let the Luftwaffe and Army fight over who would get the glory of the capture for 2 whole days, he would have captured 400,000 British/French troops.