After tragedies involving airplanes, news reporters will highlight the details associated with finding the "black box" more properly referred to as Flight Data Recorders and Cockpit Voice Recorders (the black box is in fact two different pieces of hardware). These two pieces of equipment are vital in determining what led up to the incident. What is unfortunate about the use of FDRs and CVRs in an air craft is the challenge of finding these pieces of hardware after an event. Imagine if there was a technology platform that would augment the black box, something that fully embraces how small and robust electronics are. They could be nicknamed "white envelopes" (you are now welcome to groan at this terrible attempt at a joke). White envelopes would be a small collection of chips that would receive the same telemetry as the FDR and CVR, but instead of being in a single location, the white envelopes could be spread out through out the aircraft. Now after a crash, pieces of debris can provide critical data that would improve the likely hood of finding the actual black box.
Currently black boxes mass in at around 4.5 kgs (10 lbs for those of us who landed on the moon) and generally two are required in commercial aircraft ( either an FDR and separate CVR or two boxes that have combined FDRs and CVRs). The mechanical robustness of a black box is incredible, according to the NTSB an FDR needs to survive 3000+ Gs, being submerged in 20,000 ft of water, and being cooked at 1100 C for 30 minutes, that is frickin' nuts levels of hardcore engineering, part of the reasoning for this super robustness, you only have two eggs in roughly the same basket, the plane. White envelopes could be far less robust, dozens or hundreds of small recorders don't need to be as survivable, a decent number of them are unlikely to face the same level of extreme circumstances.
The design challenges of the white envelope will be pretty tremendous, yeah you don't need to survive being baked at 1100 C but you still need to be passably strong, also what data is acceptable. In the United States the transcripts of the audio on the CVR are generally extremely restricted, do you still include the audio? Do the white envelopes record all of the sensor data provided by the aircraft? (which can mean you are potentially recording hundreds of sensors multiple times a second) These are questions that engineering teams would need to discuss. A minimum viable product might be around the size of multiple playing cards stacked on top of each other, this small volume would hold one or more memory cards (micro-SD would make the most sense under current technologies(in the opinion of the author, if you disagree please explain why other options make more sense)), wireless data recorders, and an on board controller. The controller would ensure that sensor data is actually coming from the plane's computers. In addition to this primary chip set, you would need small power packs, the reason for the power packs being separate from the data recorders stems from the mindset of maximizing system flexibility while minimizing the mass added to the plane. For white envelopes inside the cabin of the air craft, power could come from any number of electrical systems, so why generate power. Depending on where engineers decide white envelopes should be added to the plane that will dictate what the power packs would look like, ideally they would have a small battery and some kind of micro generator.
Hopefully this idea or something like it, could help in improving our ability to understand what happened after the loss of an airplane much more quickly.
Any questions of feed back please feel free to write a note
Interesting idea! As someone in aerospace field, one thing I'd add regarding potential placement of sensors/recorders is to consider embedding such technology into the critical structural members of the airframe itself.
ReplyDeleteBackground info: current innovation trends in commercial aerospace sector are focused on additive manufacturing techniques for designing and rapidly building airframes. The benefits here being reduction in overall mass with conservation of relevant material strength. In the short-term, these techniques focus on creating aircraft components using smart composite materials by way of 3D printed, laser cutting, automated fiber placement, etc. In the long-term, the holy grail is seemingly fully 3D printed composite aircraft. Additionally, there's massive innovation drives in development of smart composite structures that have embedded sensors and self-healing components or materials. For example, embedding channels in 3D printed structures through which you can pump a special type of fluid that can be released upon a specific impact type and heal cracks or fracture in the material.
Application:
With these additive manufacturing techniques in place, it should be fairly feasible to do something such as embedding additional sensoring and/or recording devices you're pointing out right into the structure that's meant to survive all crash loads already. There's critical external airframe members such as structural bulkheads along fuselage sections; the wing boxes; wing-to-body fairing joints; landing gear; aircraft doors, etc. Then there's critical internal aircraft components such as seats and other cabin components. All of these types of components are rated for the highest load cases of all the flight envelopes, in terms of safety when it comes to crash-worthiness standards meant to keep precious cargo alive (humans). Some of them are literally designed to keep the aircraft together. Additionally, a case can be made to surmise that these types of components are among the most common whole pieces of debris found after crashes.
Just a thought!
-Angelica
I had not even thought of the implications of truly embedding the "white envelope" into the structure, I was thinking that engineers would look for un-used voids in the structure of the plane. That being said, I like the concept, the deeper challenge for that kind of embedded system would be system life expectancy and reliability, removable units could be placed in the 99-ish% reliability design requirement, those that are physically integrated into the lattice of a carbon fiber wing would need to be that much more robust, that being said you would be that much more likely to find them, as there is a very low likely hood of elements being dislodged.
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