Why do pilots still die from not knowing which end is up?

http://www.airspacemag.com/military-aviation/The_Disorient_Express.html

by sajid • 15 years ago

83 79 15 years ago

bwooceli• 15 years ago

Good article, but I am a bit confused about how someone in 1906 (2nd page, top paragraph) supposedly did research on vestibular effects on pilots...

tzs• 15 years ago

I don't see anything particularly confusing about that. The Wright brothers flew in 1903, and if we don't limit ourselves to pilots of heavier than air craft, Zeppelins started flying in 1900. It would be perfectly reasonable for a 1906 researcher to look into things that might effect pilots.

That said, the article may be mistaken in the sense that the research, while applicable to pilots, appears to have actually been motivated by his work with patients suffering from dizzy spells. (BTW, he received the 1914 Nobel Prize in medicine for this research).

mechanical_fish• 15 years ago

This article includes a statistic so scary that I'm going to have to fight the urge to paste it twice:

According to a 2004 study, the average life expectancy of a non-instrument-rated pilot who flies into clouds or instrument conditions is 178 seconds.

At that rate, I'd imagine it didn't take long after the first plane flight for pilots to notice that there was a big problem with, say, closing your eyes or otherwise getting distracted while flying. Or perhaps a pilot or two tried flying into a cloud -- it's the sort of thing you'd try to do if you could, right? -- and their remaining colleagues then started wondering why flying into clouds was such a sure-fire way to die. Death sure does have a way of crystallizing such questions.

The other point I'd make is that fixed-wing aircraft research probably had obvious potential military applications even in the prewar age of 1906. Perhaps this research was funded so early for much the same reason that astronaut-physiology research was well funded even before the first astronaut reached low-earth orbit.

sliverstorm2• 15 years ago

Your parent is probably skeptical because in 1906 total human powered winged flight time could reasonably be measured in minutes. Europe still believed it was a hoax. Pilots didn't even have instruments let alone a cockpit. If you were a pilot, odds are your name was either Orville or Wilbur.

Remember, the Wright brothers first flew in 1903.

As another reply points out, it was likely blimp, balloon or some other form of aviation that spurred the research on vestibular effects.

biot• 15 years ago

I've had a similar experience while driving on a highway at night in foggy conditions. All of a sudden my car started slowing down and was rapidly losing power. I checked and it wasn't fuel, so I figured the engine was dying somehow. It wasn't until I tried gearing down that I realized I had been on a steep hill and fifth gear wasn't powerful enough. But even afterward, I couldn't sense that I was on an incline.

0x125• 15 years ago

I have a simple trick for that: I know the consumption of my car on a level road in 5th gear at 90 km/h, so when I'm in doubt about whether or not I'm going up, down or level I look at the fuel consumption indicator.

If it is higher than 6.6L/100km then I'm going up, less is down.

If you don't have a fuel consumption indicator then that will not work but lots of cars have them these days and I think using them as a level is a useful unintended application.

mkr-hn2• 15 years ago

This is the first I've heard of fuel consumption indicators. What kind of car is it?

apaprocki8• 15 years ago

Another trick might be using star alignment. A fixed position camera on the top of the plane could sense pitch by tracking which stars are in view. Or similarly, if you boxed a sensitive GPS receiver so that it could not detect signals from the sides, the satellite IDs which are in view could possibly indicate alignment of the plane as well. The best model would tie in as many observations as possible to maximize the probability that it is right.

EDIT: What about fuel sensors in the wing? If the computer knew the volume of the remaining fuel and the altitude was not dropping, it could determine the orientation of the plane if there were sensors inside the tanks to detect which were submerged.

bobroberts• 15 years ago

Unless the wind is blowing toward you.

3pt14159• 15 years ago

How are there not heads up systems that detect this? A simple "warning 5 seconds to impact with the ocean" would at least warn the pilot.

mynameishere• 15 years ago

Even little planes have those. What they need is a switch to tell the computer that they expect no descent whatsoever below xy000 feet, to stop it before it starts.

You can hear that warning here

http://www.youtube.com/watch?v=SjaU-SKYrPk

http://www.youtube.com/watch?v=LzDSq6m2zV4

apaprocki8• 15 years ago

I was going to suggest this in my post. A "dead-man"'s limit. A plane would lock you out and right itself it detected you dropped below some pre-defined altitude (e.g. within an acceptable angle without landing gear deployed or a greater than acceptable angle with or without landing gear deployed). Whatever altitude is necessary for the plane to right itself from the steepest descent. Something like that would make it impossible for someone to storm a cockpit and nose-dive a plane. It would need appropriate remote electronic and mechanical overrides, though to prevent possibly losing a plane if it was triggered incorrectly. But at least a plane flying level on lockout autopilot would buy some time opposed to it definitely being destroyed by the nose-dive.

7952• 15 years ago

But it would still require action from a pilot, who is known to be disorientated, and probably quite upset about their imminent collision with the ocean.

Perhaps an alternative would be to use a belt that vibrates differently depending on the angle of the aircraft. Humans are good at integrating data without conscious thought. This has been used with compass direction on the ground to dramatically improve spatial awareness without any conscious effort http://www.wired.com/wired/archive/15.04/esp.html.

scott_s2• 15 years ago

The end of the article talks about systems that will automatically take over if a crash is imminent.

greendot• 15 years ago

> According to a 2004 study, the average life expectancy of a non-instrument-rated pilot who flies into clouds or instrument conditions is 178 seconds.

That is a chilling statistic.

As a VFR pilot, I often wonder what would happen inside a cloud to make me react and rip my plane apart in under 3 minutes.

ispolin3• 15 years ago

Here is the fatal scenario: http://www.aerosafe.net/page6.html

As a VFR pilot, you've received basic instrument training. Remember that training, trust your instruments, and you'll make it though.

electromagnetic2• 15 years ago

With an altimeter, an artificial horizon and an airspeed indicator, you would expect a VFR pilot to be able to get through any light cloud safely.

Untrained, never having touched the cockpit of a plane, I can get the meaning from these instruments. Is it simply that pilots fly without these, or that they simply disregard them during flight?

vacri4• 15 years ago

Ah, it's from a simulator, where you don't get the benefit of your own body responses - no inner ear cues, no tactile feedback, no proprioception feedback.

People driving cars in simulators also do worse than in the real thing - a simulated car doesn't have all the ways a car tells you that you're driving close to the envelope.

0x125• 15 years ago

It's an average, you might do better.

Dramatized:

http://www.youtube.com/watch?v=fXzYZjpoz_E

orborde• 15 years ago

That was very good. I couldn't deduce what was going on until the last moment, which is (I assume) exactly the experience of pilots in this situation.

electromagnetic2• 15 years ago

I think it's that so much of our orientation is dependent on peripheral vision. I know Canadas worst pile up was caused by a heavy fog. 87 vehicles piled up, they believe in a very short time from the fog rolling in. The main factor was speed, basically people were over driving their view distance. Visibility was estimated to be something like 50 meters, but driving at 110kph gives you a stopping distance of around 150 meters. What worsened the incident was that light fog generally reduces drivers speed, but heavy fog is known to increase speed as the lack of peripheral markers means people can't gauge their speed and too few drivers check their speedometer.

I'm sure a pilot in dense cloud has the potential to make a whole host of mistakes. First I'm sure without instrumentation a pilot would quickly lose gauge on how level they're flying, or second guess how level they're flying and try to adjust. If you get caught in a cloud with a very low ceiling, there's probably not much time between exiting the cloud and that "Oh shit, that stuffs the ground". Or a slight climb and not enough thrust could easily compromise your speed and put you into a stall.

I'm quite sure 3-dimensions of travel is a real bitch when you're blind and can't stop.

vacri4• 15 years ago

Perhaps it is eaten by a grue?

omegant5• 15 years ago

Usually what will happen is that you'll think you are still flying straight but a small roll and dive will be happening, when you come out of the clouds you'll be in a very deep dive and/or almost inverted. If you don't have enough altitude to recover, you are done.

ak217• 15 years ago

I don't see this article presenting the full picture of how this problem will be addressed in the future.

As ADIRUs (navigation computers) improve to better integrate GPS and inertial signals in all conditions even when all air data is lost, weather-related instrumentation failures will decrease. Next, putting a worldwide terrain map in the navigation system will let it compute whether it will hit the ground if the course is maintained - again, even when ground radar is not working.

Next, heads-up displays or helmet-mounted displays with better warning systems will make sure that the pilot receives the warning. And most importantly, when the pilot feels that they don't know how to react to the warning, they will be able to push a button to let the autopilot return the plane to wings-level flight.

apaprocki8• 15 years ago

Given the analysis of what happened in the recent Air France crash, I can't imagine why the industry does not write better software to help combat this. It seems as if the programmers writing the software are more concerned about writing valid code to fit the designed system ("the pilot signaled us to climb at exactly 40 degrees, so do it") rather than writing code that models the real world situations accurately. I found this bit of an article about the crash the most troubling:

  It was at this point, after autopilot turned off and they
  worked to change their course, that a stall warning 
  sounded, meaning that the airplane wasn't generating enough 
  lift. The report notes the co-pilot grabbed the controls 
  and lifted the plane, which, according to aviation experts 
  is contrary to normal procedure during a stall, when the 
  nose should in fact be lowered.

If pulling back on the stick should never be done when a plane is warning of a stall, why does the software allow a pilot to do it? This is surely simplifying the situation, but I can't believe we are incapable of writing better software to prevent human mistakes.

I wonder what kind of hard limits do exist in the current avionics. For instance, is it possible to roll a Boeing/Airbus upside-down? If yes, why?

0x125• 15 years ago

What the pilot will do to keep the passenger and plane safe can't be foretold by software written in static situations on terra firma.

Sensors can lie, equipment can break. Your software may have no better idea of the true situation than the pilot.

In the end it is a judgment call and if you limit the ability of those judgment calls to a bunch of software then you are saying that those in a different time and place have a better idea of what to do than those with their feet in the dirt.

It looks like in this case someone made the wrong judgment call. False positives in warning systems in commercial aircraft are happening with some regularity, in the end the pilot has final say.

apaprocki8• 15 years ago

I think a more robust model of N completely different systems (both mechanical and electrical) to compute the same variable could be found so that the probability that it is computing a value outside of x% of the actual real value is lower than the probability that the human could make a mistake. Even if a speed indicator model in the event of pitot tube loss had a 25% margin of error, autopilot could have done the right thing or it could have possibly influenced their decision to pull back.

EDIT: You can down-vote, but this is already the direction that cars have gone. For example, there is no way to stop any Mercedes after 2009 from automatically applying full brakes in an impending collision.

http://www.daimler.com/dccom/0-5-1210220-1-1210348-1-0-0-121...

scotty792• 15 years ago

> Your software may have no better idea of the true situation than the pilot.

Also:

The pilot may have no better idea of the true situation than your software.

All that matters in the and is not who is more awesome and versatile but who crashes less planes.

antoinehersen2• 15 years ago

Pilots are very reluctant to hand over control to any kind of computer. It goes completely agains their self image. This is more true in certain company than other.

A very similar phenomenon is how the USAF crashes more drones than the Army since they use pilots that insist on flying them in manual, vs the Army operators that do not consider themselves pilot. http://www.theregister.co.uk/2009/04/29/young_usaf_predator_...

Commercial flight will become much safer when the persons in the cockpit will considere themselves plane operators vs pilots.

apaprocki8• 15 years ago

Very interesting.. Pilots that want to be rated for Cat II/III ILS landings have to perform them every now and then to stay rated, so I bet a lot of people have been through computer controlled landings without even knowing. Definitely whenever the weather is unmanageable, they have to turn over control already. Here's a really good example of something that would be very difficult for a human to do:

http://www.youtube.com/watch?v=TXJCHUmuUyw

http://www.youtube.com/watch?v=Fe_pEK_kRVw

gnaffle3• 15 years ago

I think it's easy to say that without taking into account all the experience that pilots may bring to the table when an incident occurs.

Pilots (and airlines) seem more than happy to turn flying over to the computers, in fact FAA and Airbus are concerned that modern pilots lack hand-flying skills due to over-automation. The AF447 crew did not have training in high altitude hand-flying, for instance.

Until you have a situationally aware computer that consistently beats humans in accident scenarios, we still have to trust humans to do the job, for better or worse.

vladd• 15 years ago

There are several types of "flight law" modes (see http://en.wikipedia.org/wiki/Flight_control_modes_%28electro... ) that define the set of protections enforce-able by the software.

For example, in the case of Airbus airplanes, flying in normal law's flare mode provides protection against high angle of attack and bank angle protection.

However, when something bad happens, the plane is usually switched in alternate or direct law, based on the philosophy that the software can fail and the pilot is the only one able to see the big picture and compensate for possible faulty sensor data. It's all a question of who to trust in highly-tensed situations: is the pilot suffering from vertigo or it's just a matter of faulty sensor readings due to external ice build-up?

And if the software were to override pilot decisions, just think about liabilities in case something goes wrong, which is a Pandora's box for aircraft manufacturers.

scott_s2• 15 years ago

The end of the article talks about software that does exactly this.

omegant5• 15 years ago

The airfrance crash INMHO was a lack of training( or missunderstanding of it) because the pilot flying on the captain seat ( actually a copilot, the captain was resting) was performing the maneuver for fighting windshear( you won't find this on any conclusions is my guess from his input on the sidestick).

In a stall you want to recover your speed asap , you dive and apply full throttle till you are able to level off with normal speed. Windshear usually happens when you encounter heavy wind changes on approach or take off, usually caused by heavy thunderstorms. Your speed will increase and then sudenly decrease to stall levels. It can very easily throw you to the ground.

As you are very low, the stablished procedure is to apply full throttle ( as in a stall) but PULL your controlls full up ( the software limits the nose up position to around 25 deg nose up in airbus models). You flight at the minimum speed ( airbus airplanes will not allow you to fly below that speed at least if you are at low altitude, a plane using both engines at go around power will climb). The point is that as they entered the thunderstom ( that previously was avoided by preceding airliners) and had that pitot icing, they reacted with a windshear procedure when it was unnecessary ( there is a procedure to flight without reliable speed indications just trusting your artificial horizont and thrust position for a given speed, they should have applied it in a perfect world[it is very easy to say what is the solution afterwards of course]).

At those altitudes the engines have no power left to perfor a windshear, so the speed started falling till they entered a deep stall. That stall was recoverable( this is a supposition) for lets say 2 minutes, but they still were aplying full up controlls thinking :why is this procedure that I have practiced thousand times in the simulator not working?( not understanding they were in a common stall)

It seems that the other flight officer may have known what was happening but failed to take the controls.

All this is my supposition based on the preliminary documents pblished and my experience with A320 aircrafts wich have pretty similar flight controls logic ( I am an airline pilot with 12 years experience flying boeing, douglas and airbus). Something completely diferent could be the final cause.

Windshear is a primary maneuver to practice and master due to the extreme danger that it represents for any kind of plane ( maybe not for fighters). Stall is seen as a improbable danger due to the airplane software protections. Both are practised but the windshear is more enfaticed at least in europe, also the stall is seen as a basic flying skill, something not practical to practice in an expensive simulator with limited training time for all that complicated failures.

To reply your question, you can not induce a roll to an airbus airplane ( not past 45 deg with normal conditions) unless you have lost some flight computers. You could for example with MD 80 or 737 as there are no computer protections. I don't know about 777 or other fly by wire boeings, but I guess they got some kind of protection.

Sorry for all the typos and spelling! I am writting on a van on my way to the airport.

andrewcooke• 15 years ago

the comment "Stall is seen as a improbable danger due to the airplane software protections." puts the suggestion that software do more to make things "safe" in an interesting light. thanks.

cnu• 15 years ago

One page print version - http://www.printthis.clickability.com/pt/cpt?expire=&tit...

icebraining• 15 years ago

Readability version: http://www.readability.com/articles/pcjy8rt3

crikli4• 15 years ago

"According to a 2004 study, the average life expectancy of a non-instrument-rated pilot who flies into clouds or instrument conditions is 178 seconds."

This statistic is the aviation equivalent of the "Bill Gates is going to give you $5" email forward.

The study was in 1954, not 2004, and the pilots that were tested had zero instrument time (at least three hours are required to get a license now). They were put into Beechcraft Bonanzas, aircraft that none of the test subjects had time in; Bonanzas aren't tough to fly but you definitely have to transition into them, especially if you're not used to planes with more horsepower than a Cessna 172...they get ahead of you way faster.

That said, if you're a VFR pilot and you knowingly proceed into Instrument Meteorological Conditions, you're probably in for some unpleasantness.

ra• 15 years ago

I've never flown a bonanza, but the 'doctor killer' [1] has quite a reputation.

[1] http://aviatorcollege.wordpress.com/2010/06/25/why-is-the-“d...

js2• 15 years ago

To your point - http://pastebin.com/Paj07U3f and http://www.cfidarren.com/r-178dissected.htm

nkurz3• 15 years ago

The link to the paper is given in the comments:

http://www.humanfactors.uiuc.edu/Reports&PapersPDFs/Jour...

While you are right that it is from 50 years earlier than stated, it seems like a solid study. No, it's not actually "life expectancy", but I was impressed on how well designed it was. It makes for sobering reading, but the conclusion is actually positive: with only six hours of direct experience training, they could teach people how to make a safe 180 degree turn with a high percentage of success.

They explain the choice of the Bonanza, saying it was the most complex plane that a non-professional pilot could be expected to fly. The emphasis of the study was that simple training could save lives, and thus they wanted a high bar. "In sort, the assumption was made that if the subjects, none of whom had soloed a Bonanza, could master the technique in this airplane, they could master it in any single-engine airplane under 3,000 pounds gross weight."

And it's not quite true that the pilots had zero instrument time at the time of test. The first lesson included a very small amount of time to familiarize themselves with the instruments, and were given a second try if they lost control within only a few seconds. How much of a difference this is from the current 3 hours, and how far short of the recommended 6, seems worthy of discussion and likely a more modern study.

crikli4• 15 years ago

"it seems like a solid study"

It is, provided that context is given when statistics from the paper are mentioned...which rarely happens.

To fly a Bonanza you have to have a private pilot's license, a high performance endorsement (required to fly anything with HP > 200), and a complex endorsement (required to fly anything with a constant speed prop, flaps, and retractable gear). This takes some time...and good luck getting insurance coverage (the real factor in what you do/don't fly) if you don't have an instrument ticket.

Furthermore there's a world of difference between zero or a few minutes of instrument experience and three hours. I don't have any study to back this up but I'm a pilot and can tell you from experience that the first time you go on full instruments it's sheer sensory overload. Three hours doesn't prepare you to do a decoupled IFR approach or anything, but it give you enough to do a 180.

Here's another important factor about the study that never gets mentioned: in the study the attitude indicator (artificial horizon), heading indicator, and vertical speed indicator were covered, simulating a partial failure of the vacuum system as well as a partial failure of the pitot/static system. No pilot is going to take off these instrument in failure, and should they fail in flight most pilots are getting down, now. I know I would be heading to the nearest field if I saw partial failure of both instrument systems.

So instead of saying "VFR pilots are toast in 178 seconds if they go into clouds" quotes should read more like, "if you happen to be Dr Sam Beckett and you find you've quantum lept into a Bonanza that has partial instrument system failures and you've flown into a cloud, you better hope Al can jump your ass back out within three minutes."

learc83• 15 years ago

Seems like the perfect scenario for sensory augmentation. There was an article on HN a while back about attaching electrodes to the tongue to replace vision in blind subjects.

One of the precursor experiments was attaching electrodes to the hand that were tied into a compass. The subjects were able to eventually feel North.

A similar device could be attached to something like an altimeter or other instrument.

abrowne• 15 years ago

Highly recommended piece by William Langewiesche on the same subject:

  The Turn
  At the very heart of winged flight lies the banked turn, a procedure 
  that by now seems so routine and familiar that airline passengers 
  appreciate neither its elegance and mystery nor its dangerously 
  delusive character. The author, a pilot, takes us up into the subject.

http://www.theatlantic.com/past/docs/unbound/langew/turn.htm

samstave• 15 years ago

Would not a helium balloon tethered to the floor/dash solve this problem for basically no cost?

bryanh• 15 years ago

I'm not sure it would be that easy. During turns and such, it may send the balloon fluttering in odd or unreadable directions. During such an emergency, its highly unlikely that the forces acting will be so consistant.

Sharlin• 15 years ago

A helium balloon suffers from the exact same flaw as your vestibular sense: it cannot distinguish between orientation and acceleration. There is already an instrument in every cockpit that shows the true orientation of the craft: the artificial horizon.

steve8918• 15 years ago

On Sept 6, 2011, ANA Airlines had one of their flights flipped almost 180 degrees, because one of the pilots pressed the wrong button. The weird thing is that although passengers felt the turbulence, they didn't know they had flipped almost upside down, I guess because of the same forces that confused these pilots. It's a scary thing, and if I remember correctly, its the same thing that killed JFK Jr.

http://blogs.wsj.com/japanrealtime/2011/09/29/wrong-button-s...

pazimzadeh• 15 years ago

The enemy's gate is down.

scotty792• 15 years ago

I never knew that pilots rely on their sense of movement and orientation while piloting. It seems to me like a crazy idea.

I imagined that pilot training is mostly to make people ignore the spatial feelings and stick to what they see through windows or on instruments.

mattadams• 15 years ago

Probably not the best thing for me to have read prior to a flight!

Why do pilots still die from not knowing which end is up?

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