Always with the Unintended Consequences

So, it seems like the investigation into the Germanwings crash in France is pointing towards the possibility that one of the pilots was locked out of the cabin, and unable to re-enter and prevent the ultimately fatal descent into the mountains.

a) This is horrifying
b) I'd predict that one phrase likely to be popping up sooner or later is 'who could have predicted' or one of the popular variants thereof.  Ya know, as with Condi circa 2001/2.

Were there no warnings of unintended consequences back 'round about 2002, when the FAA was frantically rethinking airport security, specifically to prevent the one particular vulnerability exploited on 11 September, 2001, without so much consideration towards the...entire rest of aviation history ?  This isn't ancient history.  I'm thinking...someone out there probably considered this sort of eventuality, and that's it's only a matter of time before a reporter unearths it.

And as for more recent history, well...

Air Canada, 2006: http://www.canada.com/ottawacitizen/news/story.html?id=37a9dd60-18a9-4155-a6bb-8a8e8976bc04
Air India, 2013: http://www.usatoday.com/story/todayinthesky/2013/05/16/air-india-captain-locked-out-after-cockpit-door-jams-mid-flight/2165305/
Transavia, 2013: http://www.telegraph.co.uk/travel/travelnews/9838956/Pilot-locked-out-of-cockpit-as-co-pilot-slept.html
LAM Mozambique Airlines, 2013: http://en.wikipedia.org/wiki/LAM_Mozambique_Airlines_Flight_470
Air New Zealand, 2014: http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11288373
Ethiopian Airlines, 2014: http://www.flyingmag.com/news/bizarre-ethiopian-airlines-hijacking-ends-copilots-arrest

That's all I found in a fairly brief search, but the prevalence of stories from 2013/4 is interesting perhaps.  Just related to the timing of the uptake of the newer technologies ?

I suspect the plane in the 2006 incident may have not had the current level of fortification, given that the crew in that story were able to 'remove the door from its hinges.'  Has some interesting verbiage nonetheless:

Eventually, the crew forced the door open by taking the door off its hinges completely, and the pilots safely landed the plane -- although in the event that the pilot was unable to access the cockpit, the first officer is also fully qualified to land the aircraft.

Air Canada Jazz said the incident is a first for them. But in Canada, a pilot getting locked out of the cockpit is a "non-reportable" incident, meaning airlines have no obligation to inform Transport Canada about it as they investigate themselves.

However, airline analysts warn that incidents like these are disasters waiting to happen -- both in terms of accidents related to human error and vulnerability to terrorism.

Oh, and one bonus story also from 2006 that may relate to earlier theories of what happened to this flight: http://www.theguardian.com/business/2006/dec/19/theairlineindustry.travel

Disturbingly, there had already been related emergencies on other airlines. After a 2003 Ryanair episode with another Boeing 737, Irish investigators had warned of "the potential for a full-scale accident" in exactly the kind of pressurisation emergency that later caused the Greek crash. They said: "With the locked door policy endeavouring to solve one specific problem, it may be creating another one or more problems that could impinge on aviation safety ... The implications for flight safety in the specific scenario of flight crew hypoxia is not being addressed by a locked cockpit door policy. This is a ... problem."

Similarly in 2004, British investigators described how a fire broke out in the passenger cabin of a British Airways plane taking off from Heathrow. Cabin staff spent time desperately banging on the locked cockpit door to try to attract the pilots' attention. The British investigation report warned that "both the flight crew and cabin crew were initially hampered in their efforts to deal with the incident promptly due to their inability to communicate with each other across the locked flight deck door."

Chris Roberts, a recently retired senior airline pilot and manager, told us: "With the locked cockpit door in place, communications are more difficult." He says: "Some regulators and airlines have dealt with this adequately but in some cases there is still more work and more training needed."

By contrast, shortly before September 11 2001, when cockpit doors were still generally open, an Aer Lingus stewardess was able to save the day by rushing in three times to warn her captain that passenger oxygen masks had dropped. Air conditioning had inadvertently been switched off. The inquiry into that incident found that oxygen deprivation had probably confused the pilots: "The continued persistence of the [stewardess] in keeping the flight crew advised of the deteriorating cabin condition did, without doubt, contribute to the safe conclusion of this serious incident."

As late as January 2001, British Airways was adamant that locked doors were too dangerous to adopt. Following an incident in which a mentally ill passenger attacked the pilots of a jumbo jet, BA chief executive Rod Eddington said: "We will not be locking the door because it does not make sense ... Locking the door would cause more safety problems than it would solve." But September 11 caused a panic reaction. Locked doors were hastily installed on planes all over the world despite a warning from the then US national transportation safety board vice-chairwoman, Carol Carmody. She said in May 2002: "We must be sure that crew communications during emergency systems are not compromised ... Access to the cockpit can be very important in an emergency."

Oh, and I'd almost forgotten this one: http://www.popularmechanics.com/flight/a10270/in-light-of-mh370-evidence-could-plane-cockpits-be-too-secure-16611747/

John Magaw, the first person to head the nascent TSA in 2001, told CNN that an always-locked cockpit was a concern since the outset. He said he told airlines, "Don't lock those doors so that you can't get in from the outside if something happens, and it fell on deaf ears," alluding to a well-publicized case of pilots who "flew past the airport because they were both asleep." However, some pilots scoffed at the idea that a locked cockpit is a serious concern, noting that planes are programmed to fly safely and even land on autopilot in the unlikely event both pilots nod off.

 Former Jetblue CEO and founder David Neeleman, whose airline was the first to install the reinforced cockpit doors system-wide after 9/11, tells PopMech that the latest troubling scenario means that "perhaps there needs to be way to get back in that door."

"But nobody ever thought about having to protect the passengers from the pilots," he says.