Sorrell Hiperbipe

Lore & Background

The Sorrell family originated from the state of Oregon, which was the last state to ban homebuilt aircraft. Hobie Sorrell petitioned Congress for experimental aircraft regulations, and his son Tim designed the Hiperbipe as part of a series of family-designed homebuilt aircraft. The SNS-7 (Sorrell Negative Stagger, Model 7) was intended to deliver full unlimited aerobatic performance while retaining cabin comfort.

The design uses mixed construction: the fuselage, tail, engine mount, landing gear mounts, interplane struts and flight controls are built from welded 4130 steel. The wings are made from wood with wooden stressed skin, and the landing gear is sprung steel tube. The engine cowling and wheel pants are fibreglass, and the entire airframe is covered in doped aircraft fabric, including the plywood-covered wings. The airfoil is a custom symmetrical design.

The SNS-7 is capable of advanced aerobatics, including vertical eight point rolls and inside and outside vertical eights. In 2015, Thunderbird Aviation acquired the tooling and manufacturing rights and began producing parts and basic kits.

Reader's Guide

The Sorrell Hiperbipe occupies a distinctive niche in homebuilt aviation as a negative-stagger cabin biplane designed for unlimited aerobatics. Its mixed construction—welded steel tube fuselage with wooden wings—reflects a pragmatic approach to amateur building, while the symmetrical airfoil and negative stagger layout contribute to its aerobatic capability. The aircraft's ability to perform vertical eight point rolls and inside and outside vertical eights demonstrates its performance envelope. The design's origin in the Sorrell family's advocacy for experimental aircraft regulations, particularly Hobie Sorrell's petition to Congress, ties the Hiperbipe to the broader history of homebuilt aviation in the United States. The transfer of tooling and manufacturing rights to Thunderbird Aviation in 2015 ensured continued availability of kits and parts. With 22 examples registered in the United States as of April 2010, plus a handful in Canada and the United Kingdom, the Hiperbipe remains a relatively rare but respected design among aerobatic enthusiasts and homebuilders.