The Normalization of Deviance

Like many pilots, I read accident reports all the time. This may seem morbid to people outside “the biz”, but those of us on the inside know that learning what went wrong is an important step in avoiding the fate suffered by those aviators. And after fifteen years in the flying business, the NTSB’s recently-released report on the 2014 Gulfstream IV crash in Bedford, Massachusetts is one of the most disturbing I’ve ever laid eyes on.

If you’re not familiar with the accident, it’s quite simple to explain: the highly experienced crew of a Gulfstream IV-SP attempted to takeoff with the gust lock (often referred to as a “control lock”) engaged. The aircraft exited the end of the runway and broke apart when it encountered a steep culvert. The ensuing fire killed all aboard.

Sounds pretty open-and shut, doesn’t it? There have been dozens of accidents caused by the flight crew’s failure to remove the gust/control lock prior to flight. Professional test pilots have done it on multiple occasions, ranging from the prototype B-17 bomber in 1935 to the DHC-4 Caribou in 1992. But in this case, the NTSB report details a long series of actions and habitual behaviors which are so far beyond the pale that they defy the standard description of “pilot error”.

Just the Facts

Let me summarize the ten most pertinent errors and omissions of this incident for you:

  1. There are five checklists which must be run prior to flying. The pilots ran none of them. CVR data and pilot interviews revealed that checklists simply were not used. This was not an anomaly, it was standard operating procedure for them.
  2. Obviously the gust lock was not removed prior to flying. This is a very big, very visible, bright red handle which sticks up vertically right between the throttles and the flap handle. As the Simon & Chabris selective attention test demonstrates, it’s not necessarily hard to miss the gust lock handle protruding six inches above the rest of the center pedestal. But it’s also the precise reason we have checklists and procedures in the first place.
  3. Flight control checks were not performed on this flight, nor were they ever performed. Hundreds of flights worth of data from the FDR and pilot interviews confirm it.
  4. The crew received a Rudder Limit message indicating that the rudder’s load limiter had activated. This is abnormal. The crew saw the alert. We know this because it was verbalized. Action taken? None.
  5. The pilot flying (PF) was unable to push the power levers far enough forward to achieve takeoff thrust. Worse, he actually verbalized that he wasn’t able to get full power, yet continued the takeoff anyway.
  6. The pilot not flying (PNF) was supposed to monitor the engines and verbally call out when takeoff power was set. He failed to perform this task.
  7. Aerodynamics naturally move the elevator up (and therefore the control column aft) aft as the airplane accelerates. Gulfstream pilots are trained to look for this. It didn’t happen, and it wasn’t caught by either pilot.
  8. The pilot flying realized the gust lock was engaged, and said so verbally several times. At this point, the aircraft was traveling 128 knots had used 3,100 feet of runway; about 5,000 feet remained. In other words, they had plenty of time to abort the takeoff. They chose to continue anyway.
  9. One of the pilots pulled the flight power shutoff handle to remove hydraulic pressure from the flight controls in an attempt to release the gust lock while accelerating down the runway. The FPSOV was not designed for this purpose, and you won’t find any G-IV manual advocating this procedure. Because it doesn’t work.
  10. By the time they realized it wouldn’t work and began the abort attempt, it was too late. The aircraft was traveling at 162 knots (186 mph!) and only about 2,700 feet of pavement remained. The hydraulically-actuated ground spoilers — which greatly aid in stopping the aircraft by placing most of its weight back on the wheels to increase rolling resistance and braking efficiency — were no longer available because the crew had removed hydraulic power to the flight controls.

Industry Responses

Gulfstream has been sued by the victim’s families. Attorneys claim that the gust lock was defective, and that this is the primary reason for the crash. False. The gust lock is designed to prevent damage to the flight controls from wind gusts. It does that job admirably. It also prevents application of full takeoff power, but the fact that the pilot was able to physically push the power levers so far forward simply illustrates that anything can be broken if you put enough muscle into it.

The throttle portion of the gust lock may have failed to meet a technical certification requirement, but it was not the cause of the accident. The responsibility for ensuring the gust lock is disengaged prior to takeoff lies with the pilots, not the manufacturer of the airplane.

Gulfstream pilot and Code7700 author James Albright calls the crash involuntary manslaughter. I agree. This wasn’t a normal accident chain. The pilots knew what was wrong while there was still plenty of time to stop it. They had all the facts you and I have today. They chose to continue anyway. It’s the most inexplicable thing I’ve yet seen a professional pilot do, and I’ve seen a lot of crazy things. If locked flight controls don’t prompt a takeoff abort, nothing will.

Albright’s analysis is outstanding: direct and factual. I predict there will be no shortage of articles and opinions on this accident. It will be pointed to and discussed for years as a bright, shining example of how not to operate an aircraft.

In response to the crash, former NTSB member John Goglia has called for video cameras in the cockpit, with footage to be regularly reviewed to ensure pilots are completing checklists. Despite the good intentions, this proposal would not achieve the desired end. Pilots are already work in the presence of cockpit voice recorders, flight data recorders, ATC communication recording, radar data recording, and more. If a pilot needs to be videotaped too, I’d respectfully suggest that this person should be relieved of duty. No, the problem here is not going to be solved by hauling Big Brother further into the cockpit.

A better model would be that of the FOQA program, where information from flight data recorders is downloaded and analyzed periodically in a no-hazard environment. The pilots, the company, and the FAA each get something valuable. It’s less stick, more carrot. I would also add that this sort of program is in keeping with the Fed’s recent emphasis on compliance over enforcement action.

The Normalization of Deviance

What I, and probably you, are most interested in is determining how well-respected, experienced, and accomplished pilots who’ve been through the best training the industry has to offer reached the point where their performance is so bad that a CFI wouldn’t accept it from a primary student on their very first flight.

After reading through the litany of errors and malfeasance present in this accident report, it’s tempting to brush the whole thing off and say “this could never happen to me.” I sincerely believe doing so would be a grave mistake. It absolutely can happen to any of us, just as it has to plenty of well-trained, experienced, intelligent pilots. Test pilots. People who are much better than you or I will ever be.

But how? Clearly the Bedford pilots were capable of following proper procedures, and did so at carefully selected times: at recurrent training events, during IS-BAO audits, on checkrides, and various other occasions.

Goglia, Albright, the NTSB, and others are focusing on “complacency” as a root cause, but I believe there’s a better explanation. The true accident chain on this crash formed over a long, long period of time — decades, most likely — through a process known as the normalization of deviance.

Social normalization of deviance means that people within the organization become so much accustomed to a deviant behavior that they don’t consider it as deviant, despite the fact that they far exceed their own rules for the elementary safety. People grow more accustomed to the deviant behavior the more it occurs. To people outside of the organization, the activities seem deviant; however, people within the organization do not recognize the deviance because it is seen as a normal occurrence. In hindsight, people within the organization realize that their seemingly normal behavior was deviant.

This concept was developed by sociologist and Columbia University professor Diane Vaughan after the Challenger explosion. NASA fell victim to it in 1986, and then got hit again when the Columbia disaster occurred in 2003. If they couldn’t escape its clutches, you might wonder what hope we have. Well, for one thing, spaceflight in general and the shuttle program in particular are specialized, experimental types of flying. They demand acceptance of a far higher risk profile than corporate, charter, and private aviation.

I believe the first step in avoiding “normalization of deviance” is awareness, just as admitting you have a problem is the first step in recovery from substance addiction. After all, if you can’t detect the presence of a problem, how can you possibly fix it?

There are several factors which tend to sprout normalization of deviance:

  • First and foremost is the attitude that rules are stupid and/or inefficient. Pilots, who tend to be independent Type A personalities anyway, often develop shortcuts or workarounds when the checklist, regulation, training, or professional standard seems inefficient. Example: the boss in on board and we can’t sit here for several minutes running checklists; I did a cockpit flow, so let’s just get going!
  • Sometimes pilots learn a deviation without realizing it. Formalized training only covers part of what an aviator needs to know to fly in the real world. The rest comes from senior pilots, training captains, and tribal knowledge. What’s taught is not always correct.
  • Often, the internal justification for cognizant rule breaking includes the “good” of the company or customer, often where the rule or standard is perceived as counterproductive. In the case of corporate or charter flying, it’s the argument that the passenger shouldn’t have to (or doesn’t want to) wait. I’ve seen examples of pilots starting engines while the passengers are still boarding, or while the copilot is still loading luggage. Are we at war? Under threat of physical attack? Is there some reason a 2 minute delay is going to cause the world to stop turning?
  • The last step in the process is silence. Co-workers are afraid to speak up, and understandably so. The cockpit is already a small place. It gets a lot smaller when disagreements start to brew between crew members. In the case of contract pilots, it may result in the loss of a regular customer. Unfortunately, the likelihood that rule violations will become normalized increases if those who see them refuse to intervene.

The normalization of deviance can be stopped, but doing so is neither easy or comfortable. It requires a willingness to confront such deviance when it is seen, lest it metastasize to the point we read about in the Bedford NTSB report. It also requires buy-in from pilots on the procedures and training they receive. When those things are viewed as “checking a box” rather than bona fide safety elements, it becomes natural to downplay their importance.

Many of you know I am not exactly a fan of the Part 121 airline scene, but it’s hard to argue with the success airlines have had in this area. When I flew for Dynamic Aviation’s California Medfly operation here in Southern California, procedures and checklists were followed with that level of precision and dedication. As a result, the CMF program has logged several decades of safe operation despite the high-risk nature of the job.

Whether you’re flying friends & family, pallets of cargo, or the general public, we all have the same basic goal: to aviate without ending up in an embarrassing NTSB report whose facts leave no doubt about how badly we screwed up. The normalization of deviance is like corrosion: an insidious, ever-present, naturally occurring enemy which will weaken and eventually destroy us. If we let it.

Ron Rapp is a Southern California-based charter pilot, aerobatic CFI, and aircraft owner whose 9,000+ hours have encompassed everything from homebuilts to business jets. He’s written mile-long messages in the air as a Skytyper, crop-dusted with ex-military King Airs, flown across oceans in a Gulfstream IV, and tumbled through the air in his Pitts S-2B. Visit Ron’s website.


  1. I had this same type of deviance normalization encounter 30 years ago flying a Lear 25 with a Part 135 operation with the company manager in the left seat as captain. We were parked on the ramp at a small airport to discharge a passenger. The captain would not shut down the engines and he directed me to open the hatch for egress of passenger. I did open the hatch and of course suffered significant hearing loss. Instead, of course, I should have just immediately moved both power levers to shut off without his clearance and just walked away from the aircraft and that incompetent, arrogant pilot. A few weeks after this incidence, this company manager pilot died while conducting a localizer/DME approach in a C-90, to a rural airport. He flew in to the rising terrain. NTSB conclusion was deficient instrument procedures and lack of approach planning. The aircraft was empty, no passengers. I was relieved of stress and satisfied when that pilot died and I and my family were soon able to move away from that decrepit western Pennsylvania town.

    • “satisfied when that pilot died”…may god have mercy on your soul.

      • I think “satisfaction” is the proper response. This jerk died alone, when he could have killed all aboard one of his revenue flights. He’d already hurt his copilot. Good riddance to bad rubbish.

        I had related feelings when a local airline pilot died – he had a FAA problem folder an inch thick, I watched him slow roll in the traffic pattern, he considered himself king of the airport wherever he flew, he expected other planes to get out of his way, etc, etc, etc. Not everyone in the pilot’s seat is worthy of mourning.

        • We’ve all known pilots with poor judgement. While we may not mourn their piloting career or decision making, every fatality is still a human life lost. Aside from the schadenfreude, I don’t see any profit in that.

          And consider this: every accident gives GA a black eye in the minds of the general public. Even if the accident didn’t cause collateral damage on the ground, it still negatively affects people’s perception of aviation. That’s bad for everyone.

          • It’s only bad if we try to conceal the incompetence of the faulty pilot. Hiding our dirty laundry does a lot of harm. It shows the public that we are incapable of policing ourselves…And that’s worse for aviation.

            I liked your article. You seemed to be upset at the numerous failures of judgement…. And upset at the hubris expressed by the Gulfstream pilots over a prolonged period. I appreciated your analysis that shows that normalization of deviance could happen to anyone; I’ll be looking for that problem in my own operations. If you’d like to pursue this further, contact me: [email protected]

        • One day, your last breath will come, whether in an airplane or in your bed. Who will mourn for your arrogant judgmental soul…?
          My guess is few…

  2. Ron,
    You really do not remove the gust lock, you stow the gust lock. This is done by securing the rudder pedals with your feet, grabbing the control wheel with one hand and depressing the release tab on the gust lock handle, gently lowering it to it’s stowed position. Great article! Rob

    • Ah. Yes, that’s definitely a better way of phrasing it. Although, if I may, you don’t depress the tab, you have to *pull* on it, then lower the lock handle gently against the pressure of the spring. 😉

      I’m just giving you a hard time. Thanks for the kind words.

      • Yeah Ron, my oops! Been out of the IV for awhile flying Globals. Still can’t believe that whole Bedford what point do you call ‘abort?’ Hope this article helps others see a similar pattern in their ops, and the mindset to correct it before they too are an NTSB rpt. Take care, Rob

        • Lucky! I was privileged to go aboard a late model Global 5000 recently, and I was quite impressed with it — especially the Vision avionics suite, the space and comfort on the flight deck, and the small details that Bombardier obviously paid such attention to.

          Your question is a good one. What would have caused the pilots to call for an abort? I don’t know. Perhaps they were so concerned about not looking bad to the boss by aborting the takeoff (and having to explain it) that they tried to cover the mistake by fixing it “on the fly”. We in corporate aviation try so hard to run the airplane efficiently for the passengers. But bad stuff happens when we rush. I’ve been there. That’s the exact time to slow down, relax, and be more methodical — not less.

          Anyway, happy holidays… enjoy that Global!

  3. “Gulfstream has been sued by the victim’s families. Attorneys claim that the gust lock was defective, and that this is the primary reason for the crash. False.” I don’t disagree with Ron. But that position reminds me of the legal challenges faced by Cessna prior to them stopping production in the 80’s. Correct me if I am wrong, but I think some people successfully pointed the finger at Cessna in cases, for example, when a pilot ran out of fuel blaming it on the lack of a low-fuel warning system. When production resumed in the 90’s, the aircraft were equipped with low-fuel annunciators.

    • Yes, there were a number of cases like that. It’s one of the reason you’ll see so many fuel drains below the wing of today’s Skyhawks and Skylanes. Your example isn’t a bad one. If the pilot ran out of fuel, is it the manufacturers fault for not having a low fuel annunicator, or the pilot’s fault for not stopping to refuel? Either way, if the lawsuits cause production of airplanes to cease, as they did in the 1980s, any victory is Pyrrhic at best.

  4. Complacency is almost always the first link in an accident – and it will cause blunt force trauma almost every time.

    • It is definitely a part of most accidents, including this one. But because of the abnormally egregious evidence chain, I’m not sure that word alone is sufficient to explain what happened here.

      I was just reading a post by Wayne Hale, a former NASA flight director and space shuttle program manager (whose blog I recommend highly, by the way), in which he quoted Diane Vaughan. Hale said that a tenet of accident investigation is asking “why” seven times. In the Bedford crash, you get to “complacency” pretty quickly. The next question is, “why (or how) did they get so complacent?” And I think those deeper questions are answered by Prof. Vaughan’s normalization of deviance theory.

      • Agreed – the accident chain is much more complex, except in certain cases, than just a single proximate cause. However, I think complacency in some form or fashion is predominately the root cause. Regardless, there but for God’s grace go I. I’ll never judge harshly the final actions of another aviator – but I will attempt to learn as much from them as possible…

  5. An aerobatic CFI?

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