GRAHAM WARWICK / WASHINGTON DC

Company is developing devices with embedded microprocessors to eventually be used in assembly of aircraft interiors

Textron Fastening Systems is developing intelligent fasteners that have embedded microprocessors remotely controlled by software-driven tools, and sees applications in controlling the assembly, disassembly or reconfiguration of aircraft interiors. Textron companies Bell and Cessna are already studying potential aerospace applications.

Using technology developed by Sydney, Australia-based TZ, Textron is developing applications initially for the automotive industry. These include tamper-proof fastening systems for airbag modules.

Other potential uses include the remote assembly of circuit cards and their later disassembly for recycling, says Seshu Seshasai, executive vice-president of technology. The smart fasteners have embedded microprocessors running a "firmware" operating system. The individually addressable microchip responds to a remote tool and controls a smart-material actuator that engages or disengages the fastener. No external force is required, says Seshasai. Textron is using shape-memory material that bends when a current is applied, activating the fastener.

In addition, smart fasteners are capable of controlling other fasteners with no intelligence, via a network, allowing a component to be assembled or disassembled with one action. This could be used to provide tamper-proof access panels, for example. The complete assembly or disassembly sequence would be controlled by software in the smart tool, which could be a hand-held computer.

The Troy, Michigan-based company sees an early aerospace application of the technology being to allow the rapid reconfiguration of aircraft interiors, such as overnight changes between passenger and cargo configurations requiring the rapid removal and installation of seats and cabin liners. The ability to customise the cockpits of general-aviation aircraft quickly by removing and installing panels and instruments is also being looked at, says Seshasai. Intelligent fasteners could also be used for access control and record keeping in aircraft maintenance, Seshasai says.

Fasteners with embedded sensors and processes can report on their operating environment and record any maintenance actions, such as when they were last activated and by whom, while software in the smart tool can restrict access to aircraft components to mechanics with appropriate qualifications. Intelligent fasteners can also be linked to the onboard network to report on the health, status and security of the aircraft.

Potential aerospace applications are "all at the drawing board stage", says Seshasai. "We have a few special applications we are working on with Bell and Cessna." Although individual microchip-equipped fasteners will be three to five times more expensive than their conventional counterparts, overall there will be savings from simplifying the design and reducing the time required for assembly, he says.

Source: Flight International