Crash Covers
Missing Franking 1942 Seattle, Wash. Terminal Annex Airmail to Meriden, Conn. with violet sl Delay Due To Air Mail Interruption At New York, N.Y. Apr 11 1942. AAMS 420411b.
Crash and other interrupted mail covers are handled like any other auxiliary marking with the additional of the reference number when available. You will be given the number. Note how the stamp missing from water damage is handled. By definition, crash cover are defective, so no condition notes are necessary.