The
Stinson L-5 'Sentinel' flew a wide variety of missions during WWII: photo reconnaissance, resupply, evacuation of wounded, message courier, VIP transport, and artillery spotting. The Army ordered this model in quantity, designating it first as the O-62 ("O" for observation), then as the L-5 ("L" for liaison) when the type designation was changed in 1942.
Behind the L-5 looks to be a Stearman PT-17.