Ryan NYP Retractable Periscope Exterior Housing Detail (Plate #3115) (1927)

Close-up photograph plate 3115 of the exterior periscope housing and prism aperture beneath the wing root on the left fuselage. — Ryan NYP Retractable Periscope Exterior Housing Detail (Plate #3115) (1927) · Donald A. Hall Estate Collection

An archival master engineering photograph (negative plate #3115) capturing a detailed macro view of the exterior periscope housing on the left side of the Spirit of St. Louis. Located beneath the forward wing root fairing and behind the damascened aluminum nose cowl, the photograph details the periscope aperture slot and prism fairing engineered by Donald A. Hall and fabricated by the Ryan crew. Because the massive 425-gallon fuselage fuel tank sat directly in front of the pilot's cockpit, blocking all forward vision, this periscope system provided Lindbergh with his sole direct forward line of sight during flight.