The 1927 two-place Sikorsky UN-4 (ATC 2-23) were modified Curtiss JN-4D fuselage with a Sikorsky-Gluhareff high-lift wing. A number were built, including C2044 and 5469.
Powered by a 90hp Curtiss OX-5 engine, the wing was adapted for other types, as well—Travel Air, Standard, etc.
All Aero 