Investigators Say FlyDubai Crash Was Caused By An "Illusion"

Sounds a lot like what happened to CI006. The instruments don't lie.

That's why I stopped reading Popular Mechanics a long time ago. This is total nonsense.

@Kris - not at all. That was an engine flame out at altitude, followed by autopilot applying max roll, crew failing to establish coordinated flight after disconnecting autopilot and then mistrusting the attitude indicator due to spacial disorientation. By that logic, this acciden is similar to [m]any other caused by spacial disorientation.

Dima, care to explain why you think it's nonsense? The explanation sounds reasonable, is in accord with the evidence, and has precedent.

This has always been the most likely cause of this accident- Disorientation due to fatigue and somatogravic illusion leading to incorrect pilot control inputs. No stall at any point.

I recently ended a 12 year stint as a professional military pilot, and illusions like the somatagravic can really challenge you up as a pilot since your body is telling you something completely different than the instruments. I have experienced its effects many times, almost always on an initial climb out or on the go after and touch and go landing. It is disorienting, but pilots are trained to deal with it and press on. Unfortunate result, but this is a well known and studied phenomenon. You can simulate something like it using a swivel chair and tilting your head so it is parallel to the ground. Then closing your eyes and spin the chair slowly for 30 seconds or so. Finally, open your eyes and lift your head to a normal position and you will feel very disoriented as your eyes and body disagree on your motion.

So can systems be designed that prevent pilots from angling the nose down under circumstances that are most likely to invoke the somatogravic illusion?

The somatogravic illusion is the result of our own internal accelerometers. Electronic accelerometers can determine when the effect is likely being experienced. Then, coupled with other information, the computer could prevent the pilot from doing something irrational in those cases.

Seems to me that this is enough of a problem - several crashes have happened as a result of it - that preventing it should be a priority for plane manufacturers and regulators.

As Justin said, pilots undergo extensive training in the psychological and physiological effects of instrument flying even before they begin their instrument training. In order to get your Private Pilot license, which is VFR only, you have to log a few hours of "hood time" (the hood is a shield worn by the pilot to obscure their view out the windows) including Unusual Attitudes, where the flight instructor has the student close their eyes and then puts the aircraft through a series of steep climbs, banks, and descents in order to disorient the pilot, then have them open their eyes, analyze the instruments, and bring the aircraft back to level flight. In short, this is basic stuff that we're trained on almost from the beginning.

I'm not trying to say the findings in the Popular Science article are rubbish. After all, this wouldn't be the first time seemingly experienced but fatigued pilots killed a bunch of people when they failed basic piloting skills. Colgan Flight 3407 is a prime example. What I find hard to believe is that BOTH pilots simultaneously failed Basic IFR 101 at the same time. More likely there was a total breakdown of communication between PF and PM. I would like to see an analysis of this crash from a Crew Resource Management perspective. I suspect there was a sizable authority gradient between Captain and FO, effectively erecting a brick wall down the middle of the cockpit. Often times such failures can be traced back to corporate culture, and the reports we've heard indicate that FlyDubai does not cultivate a safety focused culture...at least as far as their chief pilot is concerned. In other words, I suspect this crash is the result of a much, much bigger problem.

@snic- it is true that airplane avionics are not subject to the confusion that humans are. In fact, one option available to pilots in situations like this is to simply engage the autopilot and let it orient the aircraft correctly. Although, a lot of accidents start with other minor issues which make using the autopilot not recommended, like an avionics fault or sometimes poor weather conditions like icing or turbulence which depend on the limits of the specific system.

I am sure it is technically possible to have the aircraft ignore pilot commands to prevent mishaps like the one described by the Popular Mechanics article. Many (and probably most) airliners do have EGPWS which knows where the ground is based on a database loaded into the avionics. As far as I know, these systems only give verbal and visual warnings to pilots, but I would imagine that someday a further enhanced layer of safety could be added that would make it impossible to hit the ground... so long as the avionics were functioning correctly.

Popular Mechanics = Investigators?

@Chuck: Read the Popular Mechanics article. It is based on the preliminary investigation by Russian aviation authorities. It is not just speculation.

@Mark and Justin: Thanks for your answers. I find this fascinating - I didn't realize that "hood time" was part of pilot training. That's great that there's a systematic way to train pilots to ignore what their sensory systems are telling them, and it's also great that it works 99.999% of the time. It's the other 0.001% that I'm worried about.

I remember an experience during my instrument training (270 hours PP-ASEL-IA) where I had somehow moved my head up and down from the panel to the charts while executing a pitch maneuver and I could *swear* that we were flying in a 45 degree roll. As I started to correct for that, my instructor patiently said "No. Cross check the instruments. If they cross-check, you are flying correct, so IGNORE YOUR BRAIN." I really appreciate those experiences, but if I had been at the end of a long flight, I might not have remembered that.