Crazy question

[LAObserver]

Watch a lot of Air Disaster episodes and it seems that spatial disorientation or faulty/confusing artificial horizon display have led to quite a few crashes. Has anyone flown with a weighted string suspending from the ceiling as a last ditch indication of orientation? Since many commercial craft have 3 horizon displays so comparison can be made to find out which is correct if there is a fault, so having a physical string with a weight would probably never be needed but it still crosses my mind.

[Evan]

Watch a lot of Air Disaster episodes and it seems that spatial disorientation or faulty/confusing artificial horizon display have led to quite a few crashes. Has anyone flown with a weighted string suspending from the ceiling as a last ditch indication of orientation? Since many commercial craft have 3 horizon displays so comparison can be made to find out which is correct if there is a fault, so having a physical string with a weight would probably never be needed but it still crosses my mind.

What remotely recent accident has been caused by a faulty artificial horizon? Almost all passenger jets in service now use glass displays anyway. But the weighted string won't tell you where the horizon is because it will be subject to the same g-forces that you are. It would be essentially a g-force indicator, meaning it could be pointing straight down in a coordinated turn. As for the spatial disorientation aspect, which HAS caused a great many crashes, there are volumes written about that. Humans did not evolve with flying in mind and therefore the human vestibular and proprioceptive sensory organs are easily deceived. Pilots can never rely on their senses alone. If the horizon isn't visible, you are in instrument conditions, which means you fly by the instruments and if the instruments challenge your senses, you cross-check and still fly by the instruments. When pilots fail to understand this, it is a failure of training and vetting pilots, which is in turn a failure of safety culture. Anyway, I suggest you google spatial disorientation.

[3WE]

What remotely recent accident has been caused by a faulty artificial horizon? Almost all passenger jets in service now use glass displays anyway. But the weighted string won't tell you where the horizon is because it will be subject to the same g-forces that you are. It would be essentially a g-force indicator, meaning it could be pointing straight down in a coordinated turn. As for the spatial disorientation aspect, which HAS caused a great many crashes, there are volumes written about that. Humans did not evolve with flying in mind and therefore the human vestibular and proprioceptive sensory organs are easily deceived. Pilots can never rely on their senses alone. If the horizon isn't visible, you are in instrument conditions, which means you fly by the instruments and if the instruments challenge your senses, you cross-check and still fly by the instruments. When pilots fail to understand this, it is a failure of training and vetting pilots, which is in turn a failure of safety culture. Anyway, I suggest you google spatial disorientation.

One of those episodes describe a country where the AI depicts a banking airplane instead of a horizon line, and the theory was that the pilot reverted to how he USED to see things...not faulty, but...

[LAObserver]

Thanks for the answer. Recent episode I saw, the aircraft had a faulty (stuck) captain's ADI that was inexplicable noted a repaired when it wasn't. After lift off, the captain began turning left in response to the faultly ADI indication. The FO noted that his ADI matched the third ADI but did not tell the captain or take action due to fear of the captain. The flight engineer repeatedly yelled "bank angle", but the captain seemed oblivious. He continued the left turn, quickly rolling into the ground. Don't remember the accident date but it wa in Asia. And of course there is the episode when the Russian pilot rolls into the ground when he mentally reverts to Russian ADI reference which is exactly the opposite of western craft as 3WE mentioned.

[Gabriel]

As Evan explained, the string and weight doesn't work. And I don't mean that it would not be accurate: it will be meaningless. In the same way, the water in your glass don your tray in 17-B oesn't tilt about the glass when the plane turns. There is even a video of Bob Hoover serving a glass of tea while inverted, with the tea falling towards the floor of the plane even when that is toward the sky (in fact, the plane as said is inverted and is accelerating -or falling- toward the ground faster than the tea does). The string, in this situation, would also be pointing towards the floor of the plane, leading a pilot thing that the ground is also in that direction and the plane is flying straight when in fact it is inverted.

[Evan]

Thanks for the answer. Recent episode I saw, the aircraft had a faulty (stuck) captain's ADI that was inexplicable noted a repaired when it wasn't. After lift off, the captain began turning left in response to the faultly ADI indication. The FO noted that his ADI matched the third ADI but did not tell the captain or take action due to fear of the captain. The flight engineer repeatedly yelled "bank angle", but the captain seemed oblivious. He continued the left turn, quickly rolling into the ground. Don't remember the accident date but it wa in Asia. And of course there is the episode when the Russian pilot rolls into the ground when he mentally reverts to Russian ADI reference which is exactly the opposite of western craft as 3WE mentioned.

The defense against this is CRM (Cockpit resource management). When the Captain questioned his ADI, he should have cross-checked it against the F/O and the stand-by, and if he was still unsure which to trust he should have also considered his other instruments. Yes, it's all happening very fast and the effect of mental stress on cognitive functions is another can of worms but practiced procedure can allow crews to regain situational awareness before making incorrect assumptions. Some airlines just don't want to invest in this, and some pilots can't be bothered to pursue it (because they have inpeccable basic airmanship skills...) It seems to me that most pilots who fly erroneously into the ground do so with confidence.