With first flight of the 14-X waverider scramjet scheduled in 2013, Brazilian military officials have revealed details of the country's first venture into hypersonic flight tests.

The 14-X is a 2 x 0.8m (6.5 x 2.6ft) vehicle designed to demonstrate speeds beyond Mach 6.0. If the design is sound, Brazil could scale up the vehicle to deliver mini-satellites into space, says Maj Roberto Follador, 14-X flight test director for Brazil's department of aerospace science and technology.

Air-breathing scramjets, in theory, can carry 15% of their mass as payload. In contrast, rockets must carry their own oxygen for combustion, and payloads comprise only 5% of their total mass, Follador says.

Brazil launched the 14-X programme in 2006, the centennial year of the first flight of the 14-Bis - Brazil's first powered aircraft.

The first captive-carry flight test had been scheduled between 2010 and 2012, but has slipped to 2013 and could be delayed further, Follador says.

For its maiden flight, the 14-X will be joined at the front of a two-stage VSB-30 rocket, he says. The S-31 motor first stage will boost the vehicle to M4.0 before separating. Then, the S-30 motor second stage will ignite, pushing both the motor and the 14-X beyond M6.0 at about 100,000ft altitude for around 4s.

The three scramjet engines powering the 14-X will not be ignited while joined to the S-30 motor on the first flight test, Follador says.

Instead, the vehicle's designers will examine the 14-X's aerodynamic characteristics and thermal loads inside each scramjet engine, he says.

In the next series of captive carry tests, the 14-X scramjet engine will be engaged while still connected to the front end of the S-30 motor second stage, Follador says.

The 14-X will separate from the S-30 motor only on a third series of flight tests, with the scramjets powering the aircraft beyond M6.0, Follador says.

To see images of the hypersonic 14-X design, visit Stephen Trimble's The DEW Line blog

Source: Flight International