Grumman E-1 Tracer (English Wikipedia)

"WING-FOLDING MECHANISM OF THE GRUMMAN WILDCAT - An American Society of Mechanical Engineers Historic Mechanical Engineering Landmark". asme.org. American Society of Mechanical Engineers. May 15, 2006. Archived from the original on October 21, 2015. Retrieved April 29, 2017. The innovative wing folding mechanism (STO-Wing), developed by Leroy Grumman in early 1941 and first applied to the XF4F-4 Wildcat, manufactured by the Grumman Aircraft Engineering Corporation, is designated an ASME Historic Mechanical Engineering Landmark.

aviation-history.com

Dwyer, Larry (19 February 2014). "The Aviation History Online Museum - Grumman F4F Wildcat". aviation-history.com. The Aviation History Online Museum. Retrieved April 2, 2016. The F4F-4 was the first version of the Wildcat to feature a Grumman innovation, the Sto-Wing. The Sto-Wing used a novel approach using a compound angle folding-wing that was unique to Grumman...It was a successful design that was later used on the F6F Hellcat and TBF Avenger.

Lednicer, David. "The Incomplete Guide to Airfoil Usage". m-selig.ae.illinois.edu. Retrieved 16 April 2019.

"E-1 Tracer | National Naval Aviation Museum". www.navalaviationmuseum.org. Archived from the original on 2014-05-02.

"E-1B Tracer". Naval History and Heritage Command - National Naval Aviation Museum. Retrieved 2024-04-08.

Jackson, David D. "Surviving Grumman S2F Tracker Information Repository." s2ftracker.com. Retrieved: 29 October 2011.
"USA E-1B Tracers". Archived from the original on 2015-07-16. Retrieved 2015-05-21.
"United Aeronautical Corporation Tracer Photos". Archived from the original on 2015-05-30. Retrieved 2015-05-21.
"Archived copy". Archived from the original on 2015-07-11. Retrieved 2015-05-21.{{cite web}}: CS1 maint: archived copy as title (link)

"WING-FOLDING MECHANISM OF THE GRUMMAN WILDCAT - An American Society of Mechanical Engineers Historic Mechanical Engineering Landmark". asme.org. American Society of Mechanical Engineers. May 15, 2006. Archived from the original on October 21, 2015. Retrieved April 29, 2017. The innovative wing folding mechanism (STO-Wing), developed by Leroy Grumman in early 1941 and first applied to the XF4F-4 Wildcat, manufactured by the Grumman Aircraft Engineering Corporation, is designated an ASME Historic Mechanical Engineering Landmark.
"USA E-1B Tracers". Archived from the original on 2015-07-16. Retrieved 2015-05-21.
"E-1 Tracer | National Naval Aviation Museum". www.navalaviationmuseum.org. Archived from the original on 2014-05-02.
"United Aeronautical Corporation Tracer Photos". Archived from the original on 2015-05-30. Retrieved 2015-05-21.
"Archived copy". Archived from the original on 2015-07-11. Retrieved 2015-05-21.{{cite web}}: CS1 maint: archived copy as title (link)