This exterior inspection checklist from the 366th Tactical Fighter Wing's 1971 'DaNang Inflight Aid' manual details the forty-step walk-around inspection F-4 Phantom pilots performed before every combat sortie from Da Nang Air Base. Covering everything from tire pressure and hydraulic accumulators to armament safety pins and drag chute security, this methodical preflight routine was a critical safeguard for aircrews flying demanding missions over Vietnam. Project: 218454