I was following the recent Seawind 3000 crash in DeLand FL and noted that the aircraft was pretty much consumed by the fire. For rebulding N19WT, I am planning to go with three, external, RS-232 serial output, data recording systems:
My plan is to use one of my ordinary laptops to record the data to a USB stick but then I read about the fire destroying the Seawind 3000.
- Dynon 10A - electronic flight information system
- Grand Rapids Tech EIS 2000 - engine monitoring system
- fuel injection ECU - engine fuel injection system
I'm now thinking the USB stick should be in a fire-resistant, water resistant, housing with just a USB extension cable to reach the laptop. As long as the data is saved to the USB stick and it is reasonably protected against fire and water, there would be a record of what happened. So I started looking for ruggedized, fireproof and water proof housings and there isn't much out there.
As a quick hack, I'm thinking a short, steel pipe with two caps. The cable would exit via a small slot cut into the pipe or one of the caps and everything inside wrapped in glass cloth possibly micro-epoxied. The idea is to have enough thermal protection to resist a short-lived fire. Adding a voice recording file, it would pretty much have everything found in a real blackbox.
Unknown is how much heat needs to be removed from a USB stick in normal operation . . . otherwise the housing becomes a fatal, oven for the USB stick. However, a thermal fuse (aka. low temperature solder) could provide a thermal path that in a fire would melt, reducing the heat flow to the USB stick. There are other one-way thermal systems (aka., bi-metal links) that could allow heat flow out but isolate fire generated, high-temperatures from cooking the USB stick. Without power, most electronics can handle fairly high temperatures.