What kind of systems would fail without power on an Airbus A320?

Question

I'm working on a book where an Airbus A320 aircraft loses power due to EMP. What systems would fail, and what kind of backups exist? This is assuming that all electronics are fried beyond repair, and they're at altitude. Also, if you can get the standard cruise altitude for an A320, that'd be sweet.

Answer 1

yeah, I've had a friend who came to me when he wanted to write a book based on aviation thriller based on an EMP generator.



On an airbus, flight computers will all be fried. Engines will also go wacko or stop responding because engines are also now computer regulated but the generators probably would still produce electrical power, which is pretty useless because most of the things using electricity would be gone. Hydraulics, and Everything else without a computer chip or without a computer chip operating when the EMP goes off will remain operational.



The airplane is still controllable with the mechanical backup flight controls. (Airbus does have a mechanical flight control system)

Anything computerized will be gone. Radios, transponders, the FMC, the CRT/LCD displays will all go screwy. Standby instruments will still work. Depending on the airbus adequate pressurization might be affected too, if the bleed air valves are computer controlled. If there is depressurization, descent to 10,000 feet or lower will be required. Pilots would be trying to contact ATC in any way possible. If that fails, they'd be digging out old charts, and navigating by deduced reckoning (de'd reckoning) They might even get intercepted by fighters, because the people in charge on the ground would be getting mighty nervous about a hi-jacking. Communication would be reestablished when the intercept happens and the pilots visually communicate with fighter pilots. The fighters would then escort the airliner to a suitable airport.

depending on strength of the EMP, and the proximity of the EMP source, the equipment could be temporarily disabled, or permanently disabled due to melted circuits.



Common cruise alt for 320 are 28000 ft all the way up to 41,000 feet. cruise alt normally in the 30,000s , but sometimes, over the busy airways of Europe, they go as high up as they can go.



edit:

Only older style radios are not affected. standby instruments,vacuum based systems will mostly work. EMP does not kill people. Unconcentrated,undirected emps cannot harm people. It doesn't kill anything organic, it doesn't fry your brain. Only if it were concentrated, then it may become lethal to humans. For an emp to fry your brain, you'll need a long piece of metal (30 inches +) sticking out of your head, which will concentrate the EMP, and direct it into your head.



airliner systems are not shielded like military systems, and it takes relatively little to disable with an EMP, at least temporarily. Even the EMP of a huge nuke going off would not affect brain activity unless you were right next to it, in which case it would be the explosion that would kill you anyways, not the EMP.

EM energy needs metal to concentrate it. Unless you've got a pile of lead for a brain, it won't affect your nerves.

Answer 2

Hmmm... the Airbus is highly dependent on electrical power, especially its fly-by-wire.



Unfortunately, as far as I know, the Airbus 320 has no mechanical linkages, so without power the plane loses all control.



However, I must inquire how an EMP works. You say all electronics are fried, but are all electricity based systems totally gone? Now lets say the electronics are all dead... then there is no computer power to reactivate the generators, no fly-by-wire, no PA system, no radio nav aids, nothing... except...



The RAT, Ram Air Turbine. Upon loss of power gravity pulls down a little fan out of the belly of the aircraft, and the forward motion of the aircraft through the air powers the turbine which generates electricity.



Now admittedly I'm not an engineer, but I do know that the Airbus has 'fly-by-wire' and 'direct law'. Under 'direct law' the fly-by-wire computers don't handle the controls. The pilot moves the stick which activates the hydraulics directly. Full deflection of the controls gives full deflection of the ailerons/elevators (which the on-board computers normally would restrict such that the air pressure does not rip the controls right off; a real possibility at cruise speeds). Maybe, just maybe, the pilots would still have control without any computers thanks to the power generated by the RAT.



EDIT:

Okay I spoke with a guy who used to fly the 320 as both a captain and first officer. He informed me that there is a direct mechanical linkage from the foot pedals to the rudder hydraulic controls, and maybe between the side-stick and the elevator hydraulics. However there is no mechanical linkage between the sidestick and the ailerons. He offered to give me official manuals that would tell me how it's wired, but I declined (sorry, I'm not after the ten points THAT badly!).



However, we did tell me to consider this: airplanes are struck by lightning very frequently. Airplanes are designed to handle very large power spikes and, although lightning should just pass through the frame, the airplane can handle having many systems fried by lightning but still remain flyable. I think it would be very irresponsible of a manufacturer to have an airplane totally dependent on systems that could fail from a lightning strike. Therefore, I am led to believe that even if hit by an EMP, there would be enough minimally basic systems remaining to get the plane onto the ground. These systems would include airspeed, attitude, rudder, and basic engine control (even if all that was available was the fuel controls). Keeping in mind of course that the landing gear can be still be lowered even without any power (manual extension done by gravity).



I guess the question you really have to consider: how talented are the pilots in your book?

Answer 3

An EMP isn't going to fry everything. It will damage programmed chips and some IC's but it won't hurt everything. It would probably shut down an integrated navigation system, but the ADI's would probably function. The radios too.

The aircraft generators will probably work, then you'd have DC too.

If the EMP was that powerful, the pilots would probably be dead.



Edit: if the EMP was powerful enough to kill systems on the aircraft, it would affect the synaptic nerve system as well.



The EMP theory is overrated anyway. I find most of it to be superfluous BS.

Answer 4

im not a expert on the airbus A320 but I know that 70 or so % of the systems would stop but the RAT ( a little prop automatically drops down and generates power for the vital inboard systems) so if the power went out the RAT would start up in a moments notice.



P.S the cruising altitude for a A320 depends if its flying over mountains but other wise its about 12,000 Feet

Answer 5

I would think, the only operational

systems, would be -

the sun shining through the window,

the prayer in your heart.

and the 'speaking' you will feel

by the seat of your pants.