[1] The SU-1 was developed as an attempt to improve the performance of the Franklin PS-2, by designing new wings for it as a student project.
[1] Testing showed that the Stevens Institute students were successful and the SU-1 has a glide ratio of 17:1, two points better than the PS-2.
It also has a slightly higher sink rate of 180 feet per minute versus the PS-2's 150.
[1] In 1983 Soaring magazine reported that two SU-1s were still in existence, one in serviceable condition and one in need of repair.
[1] In April 2011 one remained on the Federal Aviation Administration register.