Hacker News Reader

Comment by jerrya | Hacker News Reader

I understand why in a world of easily destructible tape memory, there was only one, non-replicated flight data recorder memory. And it must've been quite heavy.

I don't understand now why in an aircraft strewn with various datalinks, there aren't a dozens or more inexpensive, lightweight easily findable flashdrives as datarecorders. You could place these at the wingtips, in the tail, in the landing gear, in all sorts of places that are known to survive.

View on HN

It's not all about economy. Flight systems are pretty complex and once cannot just have recording devices positioned everywhere (that's sorta like R2D2 plugging in some obscure data port and breaching into the death star). Black boxes are meant to resist temperature, pressure, elements and shock while keeping data secure enough for a long time until the box is recovered.

There was an excellent program on how black boxes are made and tested on Discovery or NatGeo (can't remember which), but this was the next best thing I could find http://www.yourdiscovery.com/video/discovery-news-what-does-...

I don't understand why flight data cannot be transmitted to a ground recording station in (near) real time, eliminating the need for expensive post-crash searches for the on-board recorders. I know that sometimes aircraft are out of radio/radar contact, but satellite coverage should be nearly ubiquitous. If airlines can offer in-flight internet service, surely they could be streaming their flight data back to a server somewhere.

Some data was transmitted in real-time to the Airbus maintenance facility. That's how we know (for example) that the pitot tubes appear to have failed, that the autopilot disengaged, it switched to alternate flight laws, etc.

Of course, satellite comm requires various things like intact antennas pointing the right direction. On-board recording does not.

What's the average age of a commercial aircraft? Average lifetime?

The aircraft involved, http://aviation-safety.net/database/record.php?id=20090601-0 was built in 2005. The wiki tells me flash drives first became available in 2000.

Perhaps my question is why aren't today's aircraft built with this sort of much more redundant system?

Aircraft already have redundant hydraulics, redundant data, flight controllers, fuel tanks, engines, wheels, pilots, .... Why not have "inexpensive" redundant data recorders?

Doesn't matter. They're able to retrofit other things (from seats to in-flight entertainment systems) because aircraft have relatively modular designs and because individual subsystems may need to be replaced or upgraded for safety reasons.

This kind of technology is already deployed on a limited basis in a lot of commercial aircraft. An increasingly common business arrangement is for the airline to buy the aircraft but lease the engines (which are the parts requiring the most frequent maintenance). Rolls-Royce has a global infrastructure for telemetry data designed to shorten maintenance cycles and increase safety: see http://www.flightglobal.com/articles/2009/12/09/336006/rr-tr... and http://en.wikipedia.org/wiki/Aircraft_Communications_Address... for background.

I wonder if your inexpensive flash drive operates at - 60 °C...

Wait, you actually thought he meant going to Wal-Mart and buying 1GB flash drives?

Somehow I doubt that is what the poster meant and you are just building a straw-man argument to gain points.

Insulating, heating and protecting against shock should not be harder for a flash drive than insulating, heating and protecting against impact of a tape drive with lot of moving parts inside.

More practically, I suspect the problem is the amount of time and energy taken to prove and certify a new way of doing things. Flight data recorders are standardised across most of the world and I suspect agreeing and certifing the number/location/design is more difficult than actually changing the hardware.

I believe the cost of installing reliable data drives will be significantly minuscule compared to the actual price of the aircraft and their inherent value of holding extremely valuable data.

Or being submerged for days in salt water.

It actually is made with flash memory:

http://www51.honeywell.com/aero/common/documents/Flight_Data...

You shouldn't trust major media outlets with getting the technical details right...

My guess is that we'll see this more and more, at least storage in the various components such as glass displays, air data computers etc. Lots of data is already stored for performance/maintenance purposes, which is why they were able to get some helpful data over satellite link before the plane went down.

However, everything installed on a plane needs to be certified for good reason, and unfortunately that makes even the simplest modifications expensive.

Reply on news.ycombinator.com