Hacking 2000 years from now...

I once shared this with a computer class I visited...

If you have bugs in your system, you've got headaches. If the bug has time, you've got migraines. If the bug knows the lay of the land and is also experienced, then you don't have problems with bugs, your bugs have problems with you.

cthia wrote:It has to remain a capability or it couldn't be done if need be, in case of damage to the sensors during an actual outing.

No. There are simply things you cannot do on a modern airplane with the gear down and significant weight on it. Because if the gear is down and it has significant weight on it you are ON THE GROUND. It is very, very easy to put those sort of direct inhibit circuits into the engineering systems, as David as said that nobody runs these scale wedges in the atmosphere. There would be a whole series of signals it would need to receive in the correct order to convince the system that it is actually ok to initialize.

kzt wrote:

cthia wrote:It has to remain a capability or it couldn't be done if need be, in case of damage to the sensors during an actual outing.

No. There are simply things you cannot do on a modern airplane with the gear down and significant weight on it. Because if the gear is down and it has significant weight on it you are ON THE GROUND. It is very, very easy to put those sort of direct inhibit circuits into the engineering systems, as David as said that nobody runs these scale wedges in the atmosphere. There would be a whole series of signals it would need to receive in the correct order to convince the system that it is actually ok to initialize.

But even then it can be bypassed because there are many cases of a faulty warning system or one that has given inaccurate warnings because of a simple spring or... damage.

Landing gear down tension is a function of spring preload.

kzt wrote:No. There are simply things you cannot do on a modern airplane with the gear down and significant weight on it. Because if the gear is down and it has significant weight on it you are ON THE GROUND.

I can't speak to all modern airplanes, but the F-4 Phantoms have a switch in the wheel well to bypass all of those sensors for maintenance purposes. It isn't all that difficult to put a shim in those few interlock switches that aren't bypassed by the ground maintenance mode.

There are a few cases of the nose gear being accidentally shot off during ground testing. It wouldn't be difficult at all to shoot the nose gear or launch missiles on purpose.

On the other hand, there is nothing nearly so dangerous as an impeller wedge on an F-4 Phantom. Imagine something on a modern fighter plane so powerful and potentially dangerous that merely bringing it on-line could result in the destruction of an aircraft carrier and the death of everyone aboard. I think you would need much more than a maintenance switch to bypass its sensors.

Peregrinator wrote:On the other hand, there is nothing nearly so dangerous as an impeller wedge on an F-4 Phantom. Imagine something on a modern fighter plane so powerful and potentially dangerous that merely bringing it on-line could result in the destruction of an aircraft carrier and the death of everyone aboard. I think you would need much more than a maintenance switch to bypass its sensors.

Indeed. What was needed was the pressure from a finger — on the execute button of a minicomp — belonging to a Harkness.

Weird Harold wrote:I can't speak to all modern airplanes, but the F-4 Phantoms have a switch in the wheel well to bypass all of those sensors for maintenance purposes. It isn't all that difficult to put a shim in those few interlock switches that aren't bypassed by the ground maintenance mode.

I suspect it's exceptionally hard to do it from a SSH session.

kzt wrote:

Weird Harold wrote:I can't speak to all modern airplanes, but the F-4 Phantoms have a switch in the wheel well to bypass all of those sensors for maintenance purposes. It isn't all that difficult to put a shim in those few interlock switches that aren't bypassed by the ground maintenance mode.

I suspect it's exceptionally hard to do it from a SSH session.

The weakest links of any secure system are the designers and the users.

kzt wrote:I suspect it's exceptionally hard to do it from a SSH session.

The F-4 was a 1950's design, and despite digital upgrades, it was never really "connected" the way drones and fly-by-wire aircraft are today. Of course they were hard to "hack" without physical access.

The point I wanted to make is that "safety interlocks" are easy to bypass for maintenance and/or malice. I expect that the requirement for maintenance to be able to duplicate malfunctions hidden by safety interlocks is going to persist as long as maintenance is required on technology.

In any complicated system, as it grows even more complicated threatens to become more vulnerable, because with each iteration of complication causes you to lose a bit of control. So you engineer in a cutout. Which makes it vulnerable. Again, it is the ever present human element. If you don't design with this element in mind, then you'll fall prey to it, because everywhere you are, there it is.

E.g., what happens if the premise of this thread bears fruit and "voila" a completely secure system? There are implications.

Scenario, suddenly our government is locked out of their main computers. Some idiot forgot the password. And this time, of course, he decided to heed your warning about writing it down.

The [reset] and [power] buttons act somewhat like cutouts now.