crashing vs flaming

crashing is not a noun while flaming is a noun.

Word	Noun	Adjective	Verb	Adverb
crashing	No	Yes	No	No
flaming	Yes	Yes	No	No

As adjectives, crashing and flaming are synonyms defined as:

Other synonyms of crashing include bally, blinking, bloody, blooming, fucking.

crashing (noun)	flaming (noun)
	the process of combustion of inflammable materials producing heat and light and (often) smoke

crashing (adjective)	flaming (adjective)
informal intensifiers	passionate or quick-tempered
	informal intensifiers