Interconnect for Black Box Technology in Aerospace Applications

As demands made on black boxes in aerospace applications become more complex, their overall capabilities increase and the interior space tends to become increasingly restricted

Designers may have a tendency to overlook the interconnects, or delay this element of design, with the result that the box can become an inefficient user of space, a major reliability factor and/or a cost driver.

• The use of smaller wire sizes for the inter-box highway
• The use of a ‘header’ as a one time connection principle
• The choice of connectors with pin protection
• ‘Hinged lid’ assembly techniques
• Grommets as a viable alternative to two part connectors

Designers offen specify larger wire sizes due to the requirement for reduced voltage drop and the - dated -concept that ‘larger implies stronger’. However, strength is not the key issue but flexibility can be increased by reducing the overall strand size within an individual wire core. For example, seven strands of 0.125mm diameter, which is equivalent to 28 AWG, will be more flexible than seven strands of 0.15mm diameter (26 AWG), providing that the same jacket is used.

The best design spreads the load equally among all the wires. Ribbon cables offer this advantage.