NASA set to build quiet supersonic planes

For the first time in decades, NASA is set to develop an 'experimental plane' designed to fly faster than the speed of sound without producing the noise typical of supersonic flights.

The X-plane's mission is to provide crucial data that could enable commercial supersonic passenger air travel over land.

NASA has awarded a USD 247.5 million contract to US-based Lockheed Martin Aeronautics Company to build the X-plane and deliver it to the agency by the end of 2021.

"It is super exciting to be back designing and flying X-planes at this scale," said Jaiwon Shin, NASA's associate administrator for aeronautics.

"Our long tradition of solving the technical barriers of supersonic flight to benefit everyone continues," said Shin.

The X-plane's configuration will be based on a preliminary design developed by Lockheed Martin under a contract awarded in 2016.

The proposed aircraft will be 94 feet long with a wingspan of 29.5 feet and have a fully-fuelled takeoff weight of 32,300 pounds.

The design research speed of the X-plane at a cruising altitude of 55,000 feet is 1,512 kilometres per hour. Its top speed will be 1,593 kilometres per hour.

A single pilot will be in the cockpit, which will be based on the design of the rear cockpit seat of the T-38 training jet famously used for years by NASA's astronauts to stay proficient in high-performance aircraft.

The key to success for this mission - known as the Low-Boom Flight Demonstrator - will be to demonstrate the ability to fly supersonic, yet generate sonic booms so quiet, people on the ground will hardly notice them, if they hear them at all.

Current regulations, which are based on aircraft speed, ban supersonic flight over land. With the low-boom flights, NASA intends to gather data on how effective the quiet supersonic technology is in terms of public acceptance by flying over a handful of US cities, which have yet to be selected.

The complete set of community response data is targeted for delivery in 2025 to the Federal Aviation Administration (FAA) and the International Civil Aviation Organization (ICAO) from which they can develop and adopt new rules based on perceived sound levels to allow commercial supersonic flight over land.

The X-plane's uniquely-shaped hull design generates supersonic shockwaves in the way that it makes a quiet sonic boom.

Recent studies have investigated methods to improve the aerodynamic efficiency of supersonic aircraft wings, and sought to better understand sonic boom propagation through the atmosphere.

"We've reached this important milestone only because of the work NASA has led with its many partners from other government agencies, the aerospace industry and forward-thinking academic institutions everywhere," said Peter Coen, NASA's Commercial Supersonic Technology project manager.

Jim Less is one of the two primary NASA pilots who will fly the X-plane after Lockheed Martin/s pilots have completed initial test flights to make sure the design is safe to fly.

"This is probably going to be a once-in-a-lifetime opportunity for me. We're all pretty excited," Less said.