This contrasts to small aircraft which typically have Mode A/C only (no mode S).
[0] http://en.wikipedia.org/wiki/Aviation_transponder_interrogat...
This contrasts to small aircraft which typically have Mode A/C only (no mode S).
[0] http://en.wikipedia.org/wiki/Aviation_transponder_interrogat...
All airplanes should have a MAC address. No plane should have a user-servicable-power-switch to the transponder.
Can you tell why the opposite woud be needed?
Protecting the passengers from the pilot is anyway a false goal. You can't really do it without removing the pilot.
Sound like utter BS.
Show me a case where an IN-FLIGHT transponder shutdown is a needed issue, or where this does not need a better engineered solution.
Also - Don't tell me why this is not done (based on past issues) - tell me why this is impossible to fix.
I challenge you to give me any reason in the universe which is acceptable for not tracking, in real time - uninterrupted streams, flying packages of hundreds of humans.
Give me any reasonable response to why this is not something that should be fixed.
Planes doing something strange doesn't happen often enough for it to be the most important thing in the universe.
The whole point of security is risk management. You address your most common risks first, and then the less common risks later. Electrical fires are more common than hijackings, especially after you figure in airport security. Therefore in plane design you worry about electrical fires far more than you do hijackings.
Additionally this is the first incident of its kind. This is not a typical hijacking. In fact it is entirely unprecedented. For this reason it is a game changer, and I think you are right to point that out. But electrical fires are orders of magnitude more common so you aren't going to ever risk one based on a much less likely possibility here.
To be honest, I have faith that investigators will eventually track the culprits down. Then once we know who and why we can decide what to do about it. However consider what is required to pull this off:
1. Having an airport capable of landing a 777 that nobody knows about
2. Having refuling equipment and fuel.
3. Having a hangar capable of storing the 777 out of the eyes of satellites.
These are not small requirements. Whoever did this was quite prepared. It was not pilot suicide based on the data we have. Whoever did this was large, organized, and had tons of resources (we are talking about a large drug ring or a small country here). Against a determined enemy like that I don't know that you really can stop them at the plane. Instead you need real defence in depth, and we can't even talk about that until we know more.
How would the system determine it is in-flight and thus prevent a maintenance shut down? You would need another device to determine in-flight from ground operations, and thus another device that can malfunction and thus can be defeated by an attacker.
>Give me any reasonable response to why this is not something that should be fixed.
Give me a reasonable response why spending a bunch of money to fix this rare issue is worth it over other safety improvements? Old aircraft, poor maintenance, and overworked pilots kill many times more people than hijackers.
P.S. Why don't we track buses? Why don't we track cars? Why don't we track everybody?
Buses are at alt==0 and never over an ocean - you're an idiot for comparing the two.
Why don't we track everybody? Do you understand what the NSA has been doing?
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[0] http://ycombinator.com/newsguidelines.htmlAnd what does that have to do with it? In the event of a passenger jet crashing into the ocean an enhanced transponder system would not raise passenger survival by any notable rate (because aircraft crashes where the passengers survive and aren't immediately rescued are incredibly rare in the modern age).
Aircraft hijacking where the craft and passengers go missing is incredibly rare even among hijacking incidents.
How would the system determine it is in-flight and thus
prevent a maintenance shut down?
You would connect it in parallel with something that cannot be shut down in flight.If you had a transponder in parallel with each engine, on the ground you could shut down all engines; or for an in-flight fire you could shut down a single engine; but you could not shut down all engines (transponders) while in flight.
Why don't we track buses? Why don't we track cars?
You've heard of LoJack, right? We track cars worth far less than a jet airliner.Dual transponders linked to engines is not a safe design. You are significantly increasing the chance of an aircraft crash for a slight reduction in uncertainty of the location of crashed/hijacked aircraft.
>You've heard of LoJack, right? We track cars worth far less than a jet airliner.
People voluntarily deploying tracking systems is different from mandating tracking systems.
Cars and buses are at a much higher risk of hijacking per passenger/travel distance than planes.
Certainly. There's always more than one transponder on board a big jet, for safety and redundancy reasons. If a transponder begins to misbehave, it might position the aircraft incorrectly on the ATC screen, very dangerous, or the transponder could be getting bad information from the altimeter (class C transponder), which would cause ATC to paint the aircraft at the wrong altitude -- also very dangerous.
These are just two reasons among many, for flight deck officers to require an immediate way to disable a transponder.
> Give me any reasonable response to why this is not something that should be fixed.
There's something you need to understand about the relationship between an aircraft and its pilot. The aircraft is designed to protect the pilot and the passengers, not the other way around. All this talk about protecting the aircraft from the pilot and passengers has it backwards. Obviously this means if a pilot goes crazy or someone unauthorized gets into the cockpit, the results can be catastrophic.
When changing squawk codes, it is procedure at most airlines to put the transponder into stand-by mode. This prevents inadvertent transmission of incorrect squawks should the pilots mis-key.
e.g. once squawk 7500 Hijack is transmitted, ATC must implement appropriate measures regardless of what the crew subsequently do or say. Consider that fact given 7050 is a valid non-emergency squawk.
Once the squawk has been confirmed as correct the transponder is returned to active status.
A plane being hijacked in this way is so incredible rare that having always-on transponders is not worth the safety trade off.