Scaled Composites 401

The Scaled Composites Sierra (Model 401) is an American experimental aircraft, designed and produced by Scaled Composites of Mojave Spaceport, Mojave, California, introduced in 2017. The two examples built were constructed for an unnamed customer to demonstrate "advanced, low-cost manufacturing techniques" for the production of research aircraft for both industry and government.

First flight was on 11 October 2017.

Design and development
The Model 401 is a single-seat experimental prototype of broadly conventional configuration. The pressurized cockpit is enclosed by a bubble canopy and the plane incorporates a single jet engine and retractable tricycle landing gear.

A low-wing cantilever monoplane, it has lightly swept constant-chord wings with trapezoidal inner sections. It has a butterfly or V tail.

The aircraft is made from composite material. It has a 38 ft span wing and a fuselage also of 38 ft in length. Empty weight is 4000 lb and gross take off weight is 8000 lb. The engine used is a single Pratt & Whitney Canada JT15D-5D powerplant, producing 3045 lbf of thrust.