MIAMI — Following the crash of Germanwings flight 9525, international aviation regulators and airlines are moving swiftly to implement two-person flight deck rules. If one of an aircraft’s two pilots has to leave the flight deck, and a relief pilot is not provided, a second person (usually a senior cabin crewmember) must join the remaining pilot in the flight deck until the first pilot returns.

On the surface, it might seem like a sensible move. Perhaps it is. But with calls for more action increasing, should the industry go further?

Regulations Overseas Move In Line With FAA Rules From a Decade Ago 

Broadly, the United States FAA has had a two-person rule (see section 2287 (D) (1) (g)) since 2002, requiring airlines to obtain approval for their “procedures for two-person flightcrews, when one flight crewmember leaves the flight deck (i.e., a flight attendant or other designated person must lock the door and remain on the flight deck)”.

European regulator EASA said yesterday in Safety Information Bulletin 2015-04 that it “recommends operators to re-assess the safety and security risks associated with flight crew members leaving the flight crew compartment due to operational or physiological needs during non-critical phases of flight. Based on this assessment, operators are recommended to implement procedures requiring at least two persons authorised in accordance with CAT.GEN.MPA.135 to be in the flight crew compartment at all times, or other equivalent mitigating measures to address risks identified by the operator’s revised assessment. Any additional risks stemming from the introduction of such procedures or measures should be assessed and mitigated.”

In practical terms the UK Civil Aviation Authority told Airways today: “The CAA is closely coordinating with colleagues at EASA and we believe these recommendations are a proportionate step to enhance aviation safety for the travelling public. We remain in close contact with all UK airlines and it is the airline’s responsibility to determine how to comply with this recommendation following a review of cockpit security procedures.”

Similar moves have been made by numerous international regulators, and a number of airlines are also putting procedures into place in advance of additional regulation. Even Lufthansa — parent of Germanwings — whose CEO Carsten Spohr plainly stated he did not see a need for additional regulation earlier this week, is bowing to pressure. The airline said in a statement: “in coordination with the Luftfahrtbundesamt (Germany’s aviation authority), the other German airlines and the German aviation industry association (Bundesverband der deutschen Luftverkehrswirtschaft), the airlines of the Lufthansa Group are to adopt a new cockpit occupancy procedure as a precautionary measure. Under the new procedure, two authorized persons must be present in the cockpit at all times during a flight. The passenger airlines of the Lufthansa Group will adopt the new procedure as soon as possible, in due consultation with their national aviation authority.”

Airlines worldwide are falling into step and adopting those new procedures.

The Two-Person Flight Deck Has Multiple Objectives

Initially, assumptions have been made that the purpose of these rules are for the second person to ensure the wellbeing of the pilot and by extension the aircraft. Yet approvals granted to United Airlines for single-pilot operations on nearly two dozen 777 and 787s with flight deck surveillance video suggests a regulator focus that is more about the remaining pilot not having to leave controls than on providing a check on that pilot.

Over the past days, it’s been remarkable to see the widespread astonishment from the general media and the public that a secured flight deck cannot be unlocked from the outside if the consensus (perhaps of one) within the flight deck is that it remain locked.

Yet the fact is that even without a two-person flight deck, an incapacitated pilot would not have been a barrier to a pilot returning from the lavatory. Only a pilot actively selecting the “lock” button to maintain the lock after code input would stop the door from opening.

An impenetrable flight deck has been a feature, not a problem, in the past. Almost exactly two years before Germanwings 9525, JetBlue pilot Clayton Osbon had a significant mental health event during the flight and was locked out of the flight deck by his first officer. According to the FBI, “When the FO announced over the public address system an order to restrain Osbon, several passengers assisted and brought Osbon down in the forward galley, where he continued to yell comments about Jesus, September 11, Iraq, Iran, and terrorists.” Fortunately, an off-duty pilot was also on the aircraft, and Osbon was arrested, found not guilty of interference with a flight crew on the grounds of insanity, and treated in a federal mental health facility before being released later that year. While Osbon is now suing jetBlue on the basis of allegations the airline was negligent in allowing him to fly, the fact remains that what Osbon claims was a “complex partial brain seizure” is just one reason to exclude a pilot from the flight deck.

The Two-Person Flight Deck Rule is Not a Panacea

It’s clear that regulations requiring a two-person flight deck are principally designed to avoid an opportunistic event or a sudden medical problem with the remaining pilot. A pilot determined to carry out an atrocity like Germanwings 9525 is likely to be able to — ironically, especially in the United States where pilots are routinely permitted to carry firearms.

After the attacks of 9/11, many noted that the late novelist Tom Clancy  — the 1980s Reaganite literary brain-candy equivalent of a Harlequin romance based on international relations — had outlined the effect of a commercial airliner crashing into landmark buildings. As it happens, Clancy’s hypothetical from hit novel Debt of Honor still has implications for the two-person rule.

[The pilot who would shortly crash a Boeing 747 into the US Capitol] finished his walk-around and climbed aboard, stopping first at the forward galley. “All ready,” he asked.

“Preflight checklist complete, standing by for before-start checklist,” the [first officer] said just before the steak knife entered his chest.

A truly determined pilot, acting for whatever reasons, is unlikely to be able to be prevented from taking action by a flight attendant sitting in the jumpseat.

New Rules May Well be More Effective at Passenger Reassurance Than Actual Safety

It would be entirely understandable if airlines and regulators were taking action with a primary objective of reassuring passengers. Human beings are particularly bad at assessing ‘dread risks’, those from low probability, high consequence events like many of the improbable scenarios in commercial aviation.

The speed at which the move has come from airlines and regulators lends credence to the idea that the two-person cockpit rule had long been mooted but previously suffered from inertia. Indeed, it would again be understandable if the industry had previously assessed the likelihood and potential benefits of implementing a two-person flight deck, and without the immediate impetus of a 9/11 type event driving societal requirements, concluded that on the pure hard facts that the two-person rule did not pass a cost-benefit test.

Commercial aviation, of course, does not work solely on pure hard facts, and passengers (and even regulators) are not Vulcan in their application of logic and rejection of emotion. It’s hard to suggest to a grieving family member or tabloid story writer that avoiding the interruption to cabin service — which might well be the tipping point to provide adequate revenue to ensure a route’s continuing operation — by taking one of the four flight attendants on an aircraft seating just shy of 200 people out of commission for fifteen minutes is unwise.

The thing is, there are likely to be more likely and more consequential hazards arising from passengers (either malfeasant or simply unruly) within the cabin than there are from pilots on the flight deck.

The Industry Needs to Beware of Taking a Step Too Far

Indeed, there are very real questions about whether distracting flight attendants from their existing safety tasks, and removing the senior cabin crewmember from the cabin for an indeterminate but theoretically brief period of time, actually heightens risk rather than lowering it. Drawing more attention to the specific time at which the flight deck door is open may not be entirely wise.

Security guru Bruce Schneier cites two factors that have made aviation safer since 9/11: reinforced flight deck doors, and passengers who know they need to fight back. A reasonable question is whether the passenger deterrent alone, with a flight deck door that would only delay entry, not completely preclude it, would be just as effective.

The normally thoughtful aviation beat reporter Terry Maxon at the Dallas Morning News asks “Would we rather have a plane crashed by a mentally unbalanced pilot or a terrorist?” — and an answer as glib as its question would be (c), none of the above. The crux of the question is actually another question: on the balance of probabilities, which is the more likely? While horrifying and shocking, pilot murder-suicide is infinitesimally rare, as the pilot of the dramatic 2010 QF 32 flight, Richard de Crespigny, highlights:

40 years: 591 dead in 11 world jet #suicide events. Matched in USA every 1 day (hospital errors); 6 day (gun deaths) #10; Richard de Crespigny (@RichardDeCrep)

There are many live proposals under discussion to increase aviation safety and make flying even safer than it already is. Of course, there is a finite amount of governmental and airline time and resource to make safety improvements at any one time. From live flight tracking to improved lithium battery transport procedures, from AFIRS to cabin air, from seat impact testing to electronic security, from weather forecasting to baggage scanning — is guarding against a six-times-in-the-history-of-aviation risk the one to be moving forwards?

One positive move comes from Lufthansa, which is establishing the new position of Group Safety Pilot covering all the Lufthansa Group Airlines. Captain Werner Maas “will have overarching groupwide responsibility for examining and further refining all flight safety-relevant procedures in his new capacity, in which he reports directly to Group CEO Carsten Spohr,” Lufthansa said in a statement today.

Emotional responses from fear, anger and uncertainty aren’t the answer to the deaths of 149 people at the hands of just one. Informed, considered, researched, calculated and justified action is.