Aurora - Secret Hypersonic Spyplane

From this, the next logical step was to achieve hypersonic speed. The definition of hypersonic isn't as clearly defined as supersonic, but aerodynamicists consider that the hypersonic realm starts when the air in front of the vehicle's leading edges "stagnates": a band of air is trapped, unable to flow around the vehicle, and reaches extremely high pressures and temperatures. The edge of the hypersonic regime lies at a speed of roughly one mile per second - 3,600mph or Mach 5.4. What is regarded by many as the most successful experimental aircraft program in USAF history, the X-15 rocketplane was created in response to a requirement issued by NASA (then NACA) for an air-launched manned research vehicle with a maximum speed of more than Mach 6 and a maximum altitude of more than fifty miles.

The X-15 program, which involved three test aircraft, went on to exceed all goals set and provided valuable data which has been used on many high speed/altitude aircraft of today, including NASA spacecraft, and most likely, the Aurora aircraft.

In the early 1960s, Lockheed and the USAF Flight Dynamics Laboratory began a hypersonic research program which would provide data on travel at hypersonic speed as well as more efficient shapes for hypersonic vehicles. From this program came the FDL-5 research vehicle, which beared an amazing resemblance to the North Sea Aurora sighting of Chris Gibson. Building on both the FDL-5 Project and Aurora, the aircraft which may have been seen over the North Sea could have been Northrop's A-17 stealth attack plane. Possible forms of hypersonic propulsion that Aurora could be using include: Pulse Detonation Wave Engines, Pulsejet Engines, Advanced Ramjets

Hypersonic Requirements

There are three reasons why the North Sea sketch drawn by Chris Gibson is the most persuasive rendition of the Aurora vehicle. Firstly, the observer's qualifications, with which he couldn't identify the aircraft; which would have been instantaneous if the aircraft was known to the "white world". Second is the fact that the North Sea aircraft corresponds almost perfectly in shape and size to hypersonic aircraft studies carried out by McDonnell Douglas and the USAF during the 1970s and 1980s. The third factor is that the North Sea aircraft looks unlike anything else. No aircraft other than a high-supersonic vehicle, or a test aircraft for such a vehicle, has ever been built or studied with a similiar planform. At hypersonic speeds, traditional aerodynamic design gives way to aero-thermodynamic design. In order for a hypersonic vehicle to remain structurally intact at such high speeds and stresses, the vehicle must produce minimum drag and be free of design features that give rise to concentrations of heat. The aircraft design must be able to spread the heat over the surface of the structure.