FIELD: aviation; devices protecting flying vehicle engines against penetration of foreign matter. SUBSTANCE: on-board protective device includes lower movable panel mounted in air intake body. Panel is rigidly secured on rod of drive at distance c = 0.005 to 0.01 m from leading edge of air intake; it may perform translational motion in horizontal direction and oscillatory motion at angle of α = 30 to 60 deg. and oscillation period T = 0.5 to 4.0 s. Length llow of panel and height B of midsection of air intake are made in the following relationship: 
= 0.05 to 1.2. Width blow of panel and width L of midsection of air intake are made in the following relationship: 
= 0.8 to 0.9. EFFECT: reduced probability of sucking vortex core inside air intake together with foreign matter. 3 dwg _
