Tech beyond black boxes? It just won't fly

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jammed up, causing the nose to pitch uncontrollably downward.

"Instant messaging" for pilots
Many airliners already transmit a small fraction of this information to a network of hundreds of ground stations around the world through a digital data link called ACARS, or Aircraft Communication Addressing and Reporting System. (ADS-B is another data link with similar characteristics.)

The two-way ACARS link, which works over VHF radio, resembles a kind of slow text messaging for airplanes. It lets airlines remotely request information such as fuel consumption, engine status and landing gear position. Pilots can ask for text-based weather reports from the ground.

But ACARS is designed for short bursts of information--not a constant stream of data--and is typically used only a few times during a normal flight. Revamping the low-speed ACARS system to handle the volume of information retained by a black box would be a daunting task.

"You don't need a very expensive communication network to relay information from plane to ground."

--Krishna Kavi, chairman of the computer science and engineering department, University of North Texas

Satellite links could handle the necessary bandwidth--88 data points, plus multiple audio streams stored by the cockpit voice recorder. But the cost for installation and usage makes them by far the most expensive alternative.

That's why black boxes are still the best option, says Cash, the NTSB division chief. "Who's going to store that data? Where's it all going to go? Most of it would be totally routine--99.9 percent of it would be totally routine all the time," he said. "Recording onboard is much more cost-effective and simple and reliable, knowing that you have to sometimes pay the price to find it."

One reason to maintain the current system, the NTSB believes, is the newer breed of black boxes that use solid-state memory are more likely to remain intact after a crash. Older black boxes relied on more delicate magnetic tape. (Seventy percent of U.S. commercial flights have switched to solid-state recorders.)

A bill introduced in June would require a duplicate set of black boxes that are designed to separate from the airplane at impact. That would, its proponents believe, help avoid a repeat of what happened on Sept. 11, 2001, in which flight data recorders were recovered from only two of the four hijacked planes that crashed.

Kavi, the computer science professor, has proposed a hybrid approach in which only unusual airplane data would be transmitted to the ground. "You don't really have to send all the data," he said. "What you can do is send only the data when it falls outside of normal range, so if your altitude is as it is expected, you don't need to send the data, if you think the altitude is not in the proper range, (then) transmit."

A paper Kavi co-authored titled "Glass-Box: An intelligent flight data recorder and real-time monitoring system" goes even further, however. The paper suggests permanently recording all the data that's currently stored and discarded. Once that's done, the data "collected from numerous flights can be correlated and data-mined to construct scenarios that could lead to unsafe incidents."

In such a scenario, a software program running either on the plane or the ground would analyze the data flow and detect potentially unsafe situations that a human pilot could not.

Privacy questions: a pilot's last words
Complicating the question of beaming cockpit audio to the ground is the privacy of audio recordings. Under federal law, the NTSB "may not disclose publicly" any audio from a voice recording--only an excerpt from a transcript may be released.

Computer hobbyists with radio receivers regularly capture ACARS transmissions between planes and the ground, and shareware programs with names like DACARS and KRACARS can decode the data stream. Unless the data were securely encrypted, the prospect of voice transmissions would likely encounter stiff opposition from pilots and airlines.

Airline pilots have opposed, for instance, an NTSB proposal to place cameras in cockpits and save captured video streams to the black boxes.

Still, as the price of data transmission gradually falls, industry groups expect such air-to-ground links to become more popular. Interest in technological upgrades could be spurred if Greek investigators are unable to retrieve valuable data that could have explained what killed 121 people.

"Generally speaking, real-time data link technology is a good idea," said Matt Grimison, a spokesman for the Aerospace Industries Association, which represents companies including Boeing, Northrop Grumman and Aerojet. "It holds a lot of potential...The development of the technology isn't quite where it needs to be right now in order to make it a reality, but clearly it is the technology of the future."

CNET News.com's Anne Broache contributed to this report from Washington.

[smfriedland]

Black Boxes and Data Transmissions

Data downloads from airplanes have their place - but they will not replace the black box. Data downloading systems would be useful near airports when planes on approach and takeoff could continually download information to the controllers computers - possibly alterting the controllers to a problem before it happens. The vast majority of accidents happen during approach and takeoff. It makes sense for the planes taking off and landing to transmit their data in real time.

As for the two black boxes that were lost during the World Trade Center attacks - it isn't so much as they were lost as they were destroyed beyond identification by the implosion of the buildings they came to rest in.

Black boxes have been recovered from nearly every other airplane accident - including ones over the open ocean. More than one box has been retrieved from the bottom of the ocean. It is easy to imagine an airplane attitude which would prevent any communications - upside down, for example, or pointing straight up/down. I think they will remain as a staple of accident reconstruction.

[smfriedland]

Black Boxes and Data Transmissions

Data downloads from airplanes have their place - but they will not replace the black box. Data downloading systems would be useful near airports when planes on approach and takeoff could continually download information to the controllers computers - possibly alterting the controllers to a problem before it happens. The vast majority of accidents happen during approach and takeoff. It makes sense for the planes taking off and landing to transmit their data in real time.

As for the two black boxes that were lost during the World Trade Center attacks - it isn't so much as they were lost as they were destroyed beyond identification by the implosion of the buildings they came to rest in.

Black boxes have been recovered from nearly every other airplane accident - including ones over the open ocean. More than one box has been retrieved from the bottom of the ocean. It is easy to imagine an airplane attitude which would prevent any communications - upside down, for example, or pointing straight up/down. I think they will remain as a staple of accident reconstruction.

[wazzledoozle]

Need to imrpove blackboxes not transmit the data

I mean come on! Only 30 minutes of recording time! That is so crappy. Take a small handheld digital voice recorder, throw it in a padded titanium box and put 2 mics through a small slit and youve got a perfect blackbox. Those things can record for hours.

[Titos 2 Cents]

Well, obviously it's not that simple.

Black boxes are usually stored in parts of the aircraft most likely to survive impact, not the cockpit. When I worked with these boxes, there were probably miles of wiring connecting the various sensors to the boxes near the tail. Keep in mind the expense of upgrading all of this equipment, particularly on older aircraft. When many of these digital black boxes came out (15-20 years ago) they were cutting edge technology and 30 minutes of digital recording was phenominal. Most of the commercial aircraft you fly in these days are of voting age, or older.

[wazzledoozle]

Need to imrpove blackboxes not transmit the data

I mean come on! Only 30 minutes of recording time! That is so crappy. Take a small handheld digital voice recorder, throw it in a padded titanium box and put 2 mics through a small slit and youve got a perfect blackbox. Those things can record for hours.

[Titos 2 Cents]

Well, obviously it's not that simple.

Black boxes are usually stored in parts of the aircraft most likely to survive impact, not the cockpit. When I worked with these boxes, there were probably miles of wiring connecting the various sensors to the boxes near the tail. Keep in mind the expense of upgrading all of this equipment, particularly on older aircraft. When many of these digital black boxes came out (15-20 years ago) they were cutting edge technology and 30 minutes of digital recording was phenominal. Most of the commercial aircraft you fly in these days are of voting age, or older.

[Titos 2 Cents]

Toughen future requirements, but let the current systems stay.

I'm probably one of very few tech guys who have actually worked with black boxes, the sensors, installation and whatnot. I spent some time as an avionics mechanic working on commercial MD-80/88's and did upgrades to flight data recorders to meet new FAA requirements.
These boxes are extremely tough, and are filled with components designed to take a real beating and survive intact. The only downside is the slide rule of technology since these aircraft left the line, and the huge time and money investment to upgrade this system.
A luxury car from 1985 had great bells and whistles for it's day, and the systems work well for what they were intended to do. Current luxury items are far better of course, but would you want to upgrade that 1985 model vehicle with the latest gadgets? None of the original pieces would talk to the newest equipment, and the car would be in the shop for 2 months.
For the airlines, a new mandate would be a similar scenario. None of the sensors, wiring, or collection equipment would be reusable from the analog to the digital systems. It would take downtime from service to comply with the rework, further impacting the dollar line of an already bankrupt industry. And honestly, how often are they used - when the plane crashes. Considering how rarely the devices fail or are lost, is this really a concern or someone's dream of another post-catastrophe safety device?

[Titos 2 Cents]

Toughen future requirements, but let the current systems stay.

I'm probably one of very few tech guys who have actually worked with black boxes, the sensors, installation and whatnot. I spent some time as an avionics mechanic working on commercial MD-80/88's and did upgrades to flight data recorders to meet new FAA requirements.
These boxes are extremely tough, and are filled with components designed to take a real beating and survive intact. The only downside is the slide rule of technology since these aircraft left the line, and the huge time and money investment to upgrade this system.
A luxury car from 1985 had great bells and whistles for it's day, and the systems work well for what they were intended to do. Current luxury items are far better of course, but would you want to upgrade that 1985 model vehicle with the latest gadgets? None of the original pieces would talk to the newest equipment, and the car would be in the shop for 2 months.
For the airlines, a new mandate would be a similar scenario. None of the sensors, wiring, or collection equipment would be reusable from the analog to the digital systems. It would take downtime from service to comply with the rework, further impacting the dollar line of an already bankrupt industry. And honestly, how often are they used - when the plane crashes. Considering how rarely the devices fail or are lost, is this really a concern or someone's dream of another post-catastrophe safety device?