[pavement]

Mostly, the use of a standard interface like firewire (IEEE 1394) seems to hint at economical choices being made somewhere in the supply chain, in that it probably allowed lockheed to source off-the-shelf parts, when wiring up the planes and loading software packages.

They didn't spend extra to develop or patent custom avionics superior to civilian technologies, or even try to lock secret intellectual property into the designs, to create a barrier around the fly-by-wire systems. This is a rare event when it comes to corporations interacting with government programs. Especially when fielding niche high technology line items with decades-long lifecycles.

Whether it was stipulated as part of the government program or one of lockheed's design decisions, there's a sense that the economical option provides breathing room for false compartments, without reducing superficial complexity.

[colechristensen]

Defense contractors talk a whole lot about COTS (commercial off the shelf) these days (and in the past few decades). It's a big deal to be able to not spend money reengineering something equivalent to an existing technology. It would take _years_ to create a new data comms interface (like FireWire, USB 1,2,3, ThunderBolt, etc etc) and why? The signaling physical layer and cabling design don't need to be redone do they?

They'll surely have reengineered cables and connectors to survive the aircraft environment, but who wouldn't rather buy a FireWire PHY from Mouser than design and manufacture something similar from the ground up?

Decisions like this will have happened at Lockheed and high up / early in the design phase. (i.e. it's not some subcontractor finding efficiencies but a fundamental block of the system design)