Andrew Doyle/LONDON

AN INSPECTION tool using neutron radiography will allow non-destructive testing for corrosion in aircraft structures to be carried out more quickly and effectively than with X-ray or ultrasonic techniques, according to developer Oxford Instruments.

The tool, called the Neu-SIGHT, uses a high-intensity beam of neutrons to detect areas of corrosion in aluminium. While neutrons pass freely through aluminium, they are blocked by substances containing hydrogen, such as aluminium hydroxide, a typical corrosion product found in aircraft structures.

According to Nigel Boulding, neutron-applications manager at Oxford Instruments, the Neu-SIGHT should speed up inspections because it can be used on large sections of the aircraft, avoiding the need to strip down assemblies simply to check for corrosion.

"It is very similar to X-raying," says Boulding, "but, instead of photons, which interact with 'heavy' elements, Neu-SIGHT generates neutrons, producing a shadow radiograph of hydrogen-bearing materials. It can pick up the early stages of corrosion in fairly sizeable bits of the aircraft structure."

A neutron-radiography demonstrator is operational at Oxford Instruments, developed in conjunction with Birmingham University and Rolls-Royce & Associates of the UK, and work is now focused on building a truck-mounted mobile version.

"Because of the high capital cost of the system, we intend to take it to the market as a service," says Boulding. "If they can save a day's downtime in a D-check, the airlines will come to us because it will save them money," he adds.

Source: Flight International