Lot
292 
Airmail, 1918, 16¢ green, nat. s.e., tied by purple "Air Mail Service 'Washington' Wash. N.Y. Phila., Jul 13, 1918" first-flight duplex on cover serviced by Eugene Klein, typed "Airplane Mail" endorsement, "Fee Claimed by Office of First Address" two-line handstamp, Philadelphia (7.15) arrival backstamp, Very Fine earliest date of use; with 2015 P.F. certificate. Scott No. C2 Estimate $300 - 400.
Scott has removed the listing of July 11 for a C2 First Day after being questioned by the catalogue editors in a footnote and generally disputed by specialists, this July 13 use is therefore the likely earliest recorded.
Realized: $575