John Wayne, United Airways, and Human Factors

Most everyone probably heard about the gun accidentally fired in the passenger plan cockpit last week.

But did you hear about the designs that lead to this human error?

I had to do some detective work (and quizzing gun owners) to find the following pictures:

Here is the gun in question (or similar enough) showing the safety and the spaces in front of and behind the trigger.


Pilots keep the gun in a hoster (see below).

Users report some difficulty ascertaining whether the gun is “locked” into the holster. If it is not, then the trigger can be in an unexpected place (namely, higher in the holster than the shaped holster seems to indicate.)

The TSA requires pilots who have been issued these guns to padlock the trigger for every takeoff and landing. Reports are that pilots do this about 10 times for a shift. Therefore, let’s assume we have 10 chances for error in using the holster and in using the padlock.


The padlock goes through the trigger. It should go behind, to keep anyone from pulling the trigger. If the gun is 100% in the holster, this is the case. If it is not… then the padlock can end up in FRONT of the trigger. The opaque holster prevents a visual check of the trigger.

The holster also prevents a visual check of the safety.

All of this might be forgiven, or addressed with training, if it weren’t for the fact that there are numerous other ways to prevent a gun from firing rather than locking something through the trigger. Remember, we should be on the “Guard” step of “Design out, Guard, then Train.”

I’m not even going to discuss whether pilots should have guns.

“Boyd said he supports the program to arm pilots, saying, “if somebody who has the ability to fly a 747 across the Pacific wants a gun, you give it to them.”

For an amusing take, see “Trust is not Transitive.”

3 thoughts on “John Wayne, United Airways, and Human Factors”

  1. Regarding the idea that trust is not transitive, it also reminds me of the idea that while users can be designers (or human factors evaluators), the reverse is not always true (in the sense of judging usability).

  2. If you think of it as a poorly-though-out pistol bondage gear, does it make it any less stupid? No, it doesn’t. Oh well.

    I think the USP comes in a LEO version of this pistol action, which is a lighter-trigger DA-only, sans any thumb safety. The trigger is thus, technically, the ONLY positive safety.

    It’s a perfectly safe design, however combining it with this holster would be just, well, insane.

  3. While there is a law enforcement trigger variant for the USP (one of 9 possible), it is technically not LEO, since anyone can buy it w/o enforcement stationary. While it is reasonable to assume that the LEM USP was used in this case (since the LEM variant was in response to DHS contract, IIRC), the LEM trigger is merely a lightened DA, and can still be paired with the external safety. If an agency wants to duplicate the Glock experience, they could order the LEM without the safety lever. I agree that Peter is correct in asserting that combining this variant with this specific holster would be insane.

    If the LEM without a safety was the chosen configuration, then the bigger issue here is training. The primary reason to choose the gun without the safety lever (I am going to discount concerns about snagging on the draw, as the safety is no more obtrusive than the slide lock on this gun) is the fear that under pressure the pilots would lose critical seconds remembering to sweep down the safety. When law enforcement agencies started the transition to pistols from revolvers, they moved to Glocks and other guns without external safeties (the trigger safety lever is not a safety from the user perspective) so that officers could still simply draw their guns and start firing. In theory, this allowed officers competent and trained on revolvers to start right up with pistols and not make a critical error returning to old training. I reality, this only works if your pistol never experiences any sort of jam or failure to fire (FTF). If you are trained on a revolver, the solution to a FTF is simple: pull the trigger again, moving to the next round. In the case of a FTF, few pistols offer double-strike capabilities, and in the case of a jam, the pistol requires immediate intervention before additional trigger pulls will do anything.

    Even if we assume that the logic of matching the usability of pistols to revolvers for law enforcement, in the case of training pilots, there is no expectation of collective experience with revolvers to match. The expectation is training a novice from the beginning, and training that novice to flip down a safety before engaging with lethal force seems quite reasonable. When faced with the responsibility of carrying guns on flights, the Israeli Air Marshals are known for placing a great priority on training. Since these Air Marshals carried small caliber guns, (to aid in concealment and reduce the risk of overpenetration) they relied on precision aim. Further, to reduce the risk of accidental discharge, and to allow time to regain control of a gun seized by a bad guy, the first chamber was left empty. Before they could fire their first shot (which had to be right on target), they had to perform an “Isreali draw”, racking the slide to load that first round as they brought the gun up to fire. The argument can be made that these were specialized law enforcement officers, and that they could be trained until this is an automatic process… but then pilots are individuals used to receiving levels of complex training as well.

    I think another critical issue here is politics. Many of the individuals who provide safety oversight and regulation for firearms either lack the domain knowledge to do their jobs meaningfully, or they are so opposed to the idea that they are far more interested in making things hard than they are in making things safe. While we would not put Planned Parenthood under the management of the Catholic Church or the USDA under PETA, we are forced into this exact situation with other industries, such as gun regulation and emissions management. Why? The fault rests partly with the the NRA types who are afraid to take part in any activity to restrict/define safe gun ownership or usage by government, lest they open the door for additional oversight. Therefor the only people who end up really having a say are the same people who do not want guns around, and see all guns and, generally, all gun owners the same. This bias extends into even the human factors community, where in this article, authored by an intelligent (an I can personally vouch, generally open minded 🙂 ) professional, a pilot is associated with John Wayne simply for carrying a gun legally — and a comment in the article calls up whether this should be allowed or not at all.

    How does this factor in? Because instead of stepping through each possible negative scenario, considering the worst case scenario, and addressing the hazard, a person with that initial John Wayne response is likely to get stuck at the start with “GUNS ARE BAD.” For the sake of argument, let us step through the dangers …. We are talking about the pilot, who we already trust with the lives of every person on board the plane. Suicidal or homicidal pilot? It has happened before, and without a gun he managed to kill everyone on board; the gun would not provide any advantage here. Someone steals the gun from the pilot? Hard to do without intruding on the armored cockpit when in flight, where the pilot should be using the gun to stop the intrusion. On the ground, the pilot could have the gun stolen in the airport, which would be very bad. This is a good reason for the TSA mandated locking of the gun… though the locking system is flawed. Finally, the gun could discharge accidentally. With modern firearms design, this should not be an issue, but with the current locking system/regulations this is a HUGE issue. The way I see it, we need a system that locks the gun for long enough that if someone gets it away from the pilot, he/she cannot get past the lock (without significant tools, since, after all, the person would have had to pass security for this to be an issue) until the pilot a) notices and b) security can respond. That same system should keep the gun on the pilot’s person or otherwise close by and easy to monitor to reduce both the chance of theft and the time required to notice any theft if it occurs. Finally, that system should not increase the odds of accidental discharge. If we set out to address these specific concerns with a better understanding of the systems involved and a willingness to ask for greater training commitment for the privilege of carrying a gun on a plane, there are numerous possible solutions.

    For the sake of disclosure: I did provide some of the information for the initial blog entry, and I own several firearms (including an H&K USP in .45ACP) and enjoy target shooting for fun.

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