EMMA KELLY / PERTH

Comparative vacuum technology able to detect and measure sub-1mm cracks in metal

Structural Monitoring Systems (SMS) will install its comparative vacuum monitoring (CVM) technology on a Northwest Airlines McDonnell Douglas DC-9 in early February as part of a US Federal Aviation Administration certification programme for the structural integrity system.

The Perth, Western Australia-based company will at the same time install its system on a Singaporean air force Northrop F-5 fighter in a project already under way with the installation of the sensors on the service's Aermacchi S211 jet trainers.

SMS's CVM system comprises an inert sensor adhered to the aircraft or embedded in the fuselage, a vacuum source to apply and control a low vacuum and a fluid flow measuring device. The sensor can detect sub-1mm cracks in metal surfaces, measure the crack, monitor bonded surfaces and the state of bonded joints, and measure crack initiation and propagation.

SMS is about to embark on the final stage of the programme with Northwest, with the sensors to be installed on the aft pressure bulkhead of the DC-9 for flight tests. The work, which has been driven and funded by Boeing and Northwest, is expected to be concluded in three months, says Robin Dean, SMS managing director.

The partners are already in talks regarding a possible Boeing 747-200/400 programme, while Boeing is also interested in using the technology to address an MD-80 landing gear fatigue issue and discussions have taken place with Qantas and Boeing about the 737.

The company is also discussing involvement on the 7E7 programme, with Boeing looking to embed sensors in the structure of the aircraft.

For the past two years, Airbus has been using the CVM technology to qualify new materials for the A380, particularly for determining the fatigue life of glare, says Dean. Airbus's objective is to include the technology on all new aircraft by 2008, he adds.

Civil aircraft manufacturers have identified the technology as a means to address the high costs associated with frequent inspections required for ageing aircraft - which can account for 10-15% of the operating costs of old aircraft, says Dean.

Source: Flight International