As a major early goal of the ERA project, NASA funded studies by Boeing, Lockheed Martin and Northrop Grumman of advanced subsonic transport aircraft. Lockheed Martin's concept a box-wing, biplane-like design with both swept-back and swept-forward wing sections, which were joined at their tips by vertical surfaces, was - in some ways - the most imaginative of all three designs. It relied on advanced composite materials and structures - for which the manufacturing technology has not been available until recently - to make its wing structure light enough to obtain the fuel-burn benefit that NASA's Advanced Vehicle Concept targets demanded.

Самолёты на фотографии: Aircrafts on the photo: Lockheed Martin ERA - СШАUSA - 2025

Graphic of Lockheed Martin's Preferred System Concept.

Самолёты на фотографии: Aircrafts on the photo: Lockheed Martin ERA - СШАUSA - 2025

Comparison between Lockheed Martin's Preferred System Concept and a 50% Scaled Test Vehicle.

Самолёты на фотографии: Aircrafts on the photo: Lockheed Martin ERA - СШАUSA - 2025

Three-view of the box wing design showing how unusual Lockheed Martin's concept is.

Самолёты на фотографии: Aircrafts on the photo: Lockheed Martin ERA - СШАUSA - 2025