"Whoever ... causes to be made unworkable or unusable ... any part ... used in connection with the operation of such aircraft, if such placing ... is likely to endanger the safety of any such aircraft"
The "part" is the PA system. While the device is playing the prank sound, it is temporarily "made unworkable" for its intended purpose of allowing the crew to communicate with the passangers. This "endangers the safety of the aircraft" because in certain situations it's possible the crew would need to communicate quickly with passangers or have silence so that they can understand each other and focus on solving an issue.
Edit: Looks like captain could override, flight attendants couldn't. That still causes a safety risk because in an emergency the cockpit might want to focus on flying the plane while the flight attendants instructed the passangers. Plus the distraction factor remains.
I don’t deny that it’s an important safety system. I’m curious, though, if they’re treated like safety critical systems in design or if emergency training covers how to act if the PA is down.
I'd assume it's important to safety, but they have slightly less effective backups like yelling. I think the backup systems on aircraft are often things you'd rather not need to use.
Plugging in a Bluetooth transmitter into a user-accessible port and using the system as intended is "hacking" now?
Sure, passengers weren't intended to use that port, but from a system perspective the system is being used as intended with no interference or exploitation.
I'm not sure this system can even be "hacked" short of disassembling parts of the plane and tapping into the communications wiring.
We can debate if I've used "hacked" loosely without giving too much thought to my comment, but my point is that whoever did this (on a few flights, allegedly) has "gained unauthorized access to a computer system" (which broadly fits most definitions I find). Besides, unless I missed something we have no idea if they just paired with Bluetooth or did something else.
Maybe I'm off-base and they're just risking an airline ban, but it seems (to my uninformed opinion) that doing that on an flying airplane is playing with fire that the airline won't sue and that, if they do, it'll be a clement judge which won't make an example out of them for messing with an airplane's computer, safety critical or not.
Depending on the technical means used, it might not be proper to consider it to be hacking in, say, the CFAA sense, but you're still not supposed to do things that have the result of preventing a flight crew from making announcements to passengers. Even if you did those things with an otherwise perfectly legitimate means like playing a sound with a cell phone, playing a sound with a tape recorder, or playing a sound with your voice.
I would be happy to agree that the CFAA is overbroad. But disruptive actions toward flights and aircraft are quite reasonably punishable under other theories, when they could plausibly create a risk for aviation, regardless of the means.
I think a case could be made that it's unauthorized access, since the prankster is definitely not supposed to be using the system for those purposes, regardless of how accessible it is. Same as if you walked into a bank or something and surreptitiously plugged a malicious USB drive into one of their machines.
Maybe it would make a difference if the prankster was an employee, and not just some random person, but I doubt it.
Right. My comment didn’t assume a specific interface method (user accessible port / medical jack vs. something else) but rather a method to play the audio without having to be on the plane (which would certainly be my preference were I the prankster.) If it was actually done using a user accessible port intended for access to the PA, I would agree with you, it wouldn’t fall under CFAA/hacking type laws. Still could be problematic legally though.
Microcontrollers are small enough now that there could be lots of interesting ways to interface.
EDIT: Also, based on the OP, the PA gets power cycled repeatedly on at least one flight where this is happening. That’s much more intrusive.
It's literally only the media, and not the law enforcement, that use the term "hack." The word "hack" probably doesn't even exist in any criminal code.
Law enforcement use phrases like "unlawful access to a protected system" and whatnot.
49 U.S. Code § 46504 - Interference with flight crew members and attendants
An individual on an aircraft in the special aircraft jurisdiction of the United States who, by assaulting or intimidating a flight crew member or flight attendant of the aircraft, interferes with the performance of the duties of the member or attendant or lessens the ability of the member or attendant to perform those duties, or attempts or conspires to do such an act, shall be fined under title 18, imprisoned for not more than 20 years, or both. However, if a dangerous weapon is used in assaulting or intimidating the member or attendant, the individual shall be imprisoned for any term of years or for life.
I think the other statute is somewhat more relevant, because I'm not sure this is "assaulting or intimidating a flight crew member or flight attendant" (as it's more targeted against infrastructure than people!). I agree with the thought that a public address system is a "part" of an aircraft whose reduction in serviceability "is likely to endanger the safety".
You might argue that flight crew could be intimidated by the knowledge that their aircraft is behaving unusually, but I don't think that's particular core territory of "assaulting or intimidating".
not sure. A cursory reading of https://www.law.cornell.edu/uscode/text/18/32 doesn't mesh with a silly prank. Which law do you think they are breaking?