Hacker News Reader

Comment by mschuster91 | Hacker News Reader

I think it's time for the FAA/JAA to make a regulation that blackbox batteries have to last 3 months or longer. Should not be too much of a cost to retrofit, compared to stuff like live FDR transmission via satellite.

View on HN

It's hard to design for outlier data. This is the most unusual search in modern aviation history. It is the outlier. With a couple of exceptions, all crash zones are found within days.

What makes you think that increasing the battery by a couple of months will deal with the next extraordinary case? What you're suggesting isn't even an order of magnitude more, though 30 days is already a couple of orders of magnitude more than what is needed 98% of the time.

Hindsight is 20/20.

Or just automatically eject floating GPS beacons on impact. You only need one good ping to the satellite to define the crash area.

This is not the first time this has happened. After Air France there should have been some added location method, it took two years to find the black box.

This. It's crazy that it doesn't already work this way.

Don't even wait until impact... it should just be the first part that (intentionally) falls off the plane when a critical sink rate threshold is crossed.

Sinkrate is a bad indicator. If this thing flew until it ran out of fuel, it could have had a reasonable decent that would fall into acceptable sinkrates.

True in this case, but here, the eject-on-impact feature would presumably be the relevant one.

Are you seriously suggesting that a passenger airliner deliberately eject an object from itself based on nothing more than the rate at which it is descending?

Hazard to people or structures below? Hazard to the airplane if it impacts a control surface? Hazard to the airplane caused by a misfire of the eject mechanism? Inherent danger of the eject mechanism (I'm assuming it would have to be a chemical explosive due to the need to get it far away from the airplane so it doesn't cause the second hazard above)?

Ejection seats have the same problems, but at least their deployment is pilot-actuated.

Hazard to people or structures below?

Given that they're about to get an aeroplane in the face anyway, an acceptable increased risk :)

You're assuming (a) no false triggers and (b) the path of the airplane is the same path the ejected box will take.

You'd probably be genuinely disturbed to learn just how often stuff falls off of planes.

Actually, no: having been a student pilot at one time, I spent a lot of time reading about the many things that went wrong with airplanes.

That doesn't mean I still don't think this is a bad idea.

I'm sure the plane had some ELTs. Perhaps the impact was just too great? The liferafts contain them as well, but since they're stowed in bags it is unlikely that one would be freed and remain on the ocean surface.

We do this already. http://en.wikipedia.org/wiki/Crash_position_indicator

I live in an airport approach corridor. The noise is nuisance enough, don't drop crap on my house or my head because a nut job pilot decided to drop an airliner in one of the most remote ocean areas on the planet.

Similarly, I've heard that the cockpit voice recording only keeps the last two hours. While that deals with 99% of the cases, here it will miss out on all conversation near the point that the flight began to go off course, and indeed hours after that.

What would be the cost to simply bump the recording time up closer to the maximum flight time possible on a full tank?

Its mostly because of protecting the crew's privacy. The unions will reject and fight against an increase to the recording time.

You wouldn't necessarily need to increase the battery capacity. You could increase the time between pings. First week after activation, ping at the rate they do now. Then start increasing the interval.

The idea would be to have some pings still happening even after a very long time, because if it gets to that point it is clear no one knows where to look and the thing is only going to be found by accident, when something that listens for other reasons (submarine, research vessel) happens to pass near it.

There already are such regulations on the way. The European Aviation Safety Agency and the FAA are both likely to start airlines switching over to 90 day batteries within a year or two. The EASA is also looking at increasing the range of the locator ping (by adding an additional lower frequency pinger for planes that do long trans-oceanic flights, I think), and extending the voice recording time from 2 hours to 15 hours - perhaps the FAA is planning something similar.

http://www.flightglobal.com/news/articles/mh370-loss-coincid...

http://www.newscientist.com/article/mg22229634.500-five-ways...

You're just patching a specific bug by adding a special case for it. That's no way to engineer anything. Also, you use the typical fallacy of a fix being just a minor bit of work. If it was low cost and easy to do it'd be done already. Batteries are big and heavy. Increasing the size and weight of the black box is a tricky proposition because it would make it more vulnerable to damage, so you'd need to re-engineer the whole thing to make it stronger. That would make it much heavier and much larger than it's been. And because of such major engineering changes you have to completely redo every aspect of testing. Then you have to begin manufacturing new ones and replacing them in every single plane out there. And every single plane now needs to be extensively retrofitted and updated.

I wonder if they could fit them with auxiliary saltwater batteries. So they have N days of power from the main battery, then an additional M days if they land in the sea. Given that it takes a lot longer to find crash sites at sea, that's the main place they need extra energy.

That said, i have absolutely no idea if a saltwater battery actually has a higher energy density than some other kind of battery. Probably not.

If it separated from the plane and floated, it could be sunlight powered.

Ok great idea philosopher king, let's make the regulation to demand 90 days ping endurance.

Just one caveat, make sure you open your checkbook for this one, not the rest of us who don't want to pay for yet another trivial feature creep crap every time we buy a flight ticket.

Better pay for the fact that in case my plane crashes into the ocean, the plane will be found instead of paying for useless magazines/newspapers I don't read anyway...

Please don't make aggressively sarcastic comments on Hacker News. It goes against our two most important values: signal/noise ratio and personal civility.

Reply on news.ycombinator.com