No, obviously global warming caused the crash. Can't you see it? {/sarc}
There needs to be some type of safeguard against the forced closure of a cockpit (and overide) from the inside.
It is a bad idea to continually add technical design solutions on top of existing technical design solutions to low probability events. It not only drives up the cost of the airplane, but drives up the cost of operating the airplane, AND each new design feature on top of existing design features also INCREASES the chance of a failure mode which defeats the entire purpose of one of the design safeguards. Engineering cannot solve "people problems" and, in fact, when we aerospace engineers do our safety analysis of our designs, the certification agencies do NOT force us to try to quantify the probability that the human does the wrong thing. Because what sort of probability could one reasonably assign to such an event, and how would you show it is a valid probability? Our designs DO sometimes contain features that protect against the human doing the wrong thing (e.g. autopilot airspeed command selections are limited to within the safe operating envelope so the machine will never let the human select a speed that is too slow or too fast), but as you add more and more of these features without a valid safety probability of hazard model, you begin to see other, negative effects of these design solutions.
Exactly. The other pilot should always be able to get in.
Ah, the opinions of the lay public. It is easy for the non-professionals to levy what sounds like such a simple requirement. But you have never had to take this requirement, do ALL of the deep analysis of how it must be implemented (deriving more detailed design requirements that respond to this high level thought), and then have to come up with a design solution that meets the intended function more than 99.99% of the time, but also does NOT introduce hazardous or catastrophic failures modes when the design solution is implemented.What is really going on here is you are making a judgment out of ignorance for how the existing design should be changed. I say out of ignorance because you have no understanding of why the design is the way it is to begin with. I can shed light on why it is this way.
There are three modes mandated for how the cockpit door is to be locked/unlocked. These three modes are:
1) Unlocked
2) Normal
3) Locked
In the case of Normal, this is where the door is actually locked to people from the outside, BUT it does allow a crew member who knows the code to enter it on the code pad and overrride the lock. So the natural question for the uninformed is "why do you need the locked mode?". The locked mode is where the flight crew inside the cockpit can PREVENT the code override feature, as we saw in this accident. The REASON that feature is mandated is because forward-thinking engineers KNEW there was a very real (and very probable) risk of that access code being compromised. Just like there is a very real probability that hackers can figure out passwords and compromise the security of many of your computer accounts.
So, the LOCKED mode was mandated in the design to address the very real (not remote) probability that the code was compromised by a criminal. This mode is based upon the presumption that adequate screening of flight crews has been done such that we believe we could prevent situations like this A320 case from happening. But obviously, human controls are more susceptible to failure than design controls because of human variability, and the ability of a human to hide things about their intentions.
Engineering cannot solve ALL human security problems without unintended consequences. If we tried to, either you would not be able to afford the final system, would not be able to prove it is effective at least 99.99% of the time, or it would possess failure modes that result in diminishing returns from having attempted to implement it.
RMT
