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Posts Tagged ‘crashes’

‘Massage’ seats proposed for airline pilots.

20/02/2011 1 comment

The modern aircraft cockpit is fully-loaded with all kinds of attention-getting devices: Alarms, buzzers, lights, stick-shakers, etc. Boeing thinks there needs to be a new one: Flight crew seats that vibrate (at various amplitudes and frequencies). (Article on Flight Global) Flying by the seat of your pants may be making a return of sorts…!

Stress vs Performance Curve

Stress vs Performance Curve

Seriously, though, do we really need another means of getting a pilot’s attention? You COULD introduce vibrating seats. You could also introduce neon lights on the cockpit window frames. Or play music from Top Gun in the cockpit if your approach gets too high on energy (on seconds thought, that last one is probably a really bad idea).

Pilots learn in Human Factors about the stress vs performance curve (shown on right). One has to wonder sometimes if cockpit systems designers have ever been introduced to the concept. Too many alerts, which, when multiple sound at once, create another ‘link’ in the accident ‘chain’, pushing crews onto the ‘back-side’ of the stress curve, degrading or eliminating their utility.

Bells, alarms, etc. have their place, but too many create an ‘overload’ situation, and errors become likely. I am presently reading “The Limits of Expertise“, which takes a look at ‘human error’ from a new perspective. In it there are many examples of accidents that could have been avoided if a clearly audible alarm had been heeded. However, the crew was already over-loaded at the time, with an unstable approach, or perhaps some other fault they expected an alarm for, masking the new information.

One of the suggestions of how this new vibrating seat could be used is to enable ATC to activate it. If an aircraft fails to make radio contact when expected, for instance, ATC could activate your seat buzzer, alerting you to… something. Either you forgot to contact ATC or you’re about to fly into the ground, or…

Having different frequencies of vibration MAY alert the crew to a specific issue IF they are familiar and well practiced in sensing the different frequencies, AND if they’re not already on the back side of the stress curve, which given the fact they are being alerted, they probably already are.

If ATC could be given the ability to trigger an alert on a desired aircraft, why make it a vibrating seat? Why not a sort of text message? A chime announcing a message displayed in the cockpit could be more specific and more useful while being less confusing to an over / under stimulated crew.

In conclusion, a vibrating seat ‘alarm’ is a valid idea, but in combination with existing alerts, it’s just as likely to cause confusion and problems as it is to solve them. The use as an ATC triggered alert is a red-herring; If such an idea could be implemented, there are surely better ways of doing it.

Finally, a humourous illustration of my point:

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Categories: aerospace, airmanship, crashes

Airmanship (AWOL)

This is a bit of a negative start to the blog, but nevertheless…

The USAF is considering a ban on airshow displays of large aircraft (that is, bombers and transports) following the loss of a C-17 practicing for an airshow display on July 28 2010 at Elmendorf-Richardson in Alaska.

The remains of the tail of the C-17 after the crash

The remains of the tail of the C-17 after the crash

Banning airshow displays of large aircraft would certainly reduce the risk of losing additional aircraft and crews on airshow related flights (banning airshow displays entirely would save more…), but doing so would be treating a symptom, not the cause.

This is not the first time a large USAF aircraft has been lost practicing an airshow routine. A very similar accident occurred in 1996, this time involving a B-52 at Fairchild AFB. Both accidents were caught on video:

(Even longer version, showing entire display)

Both aircraft crashed while performing very steep, low-speed, low-altitude turns.

Both aircraft busted USAF regulations regarding airshow displays (such as safe height).

Both aircraft flew outside of the permitted flight envelope.

Both pilots were considered very highly skilled.

Both pilots knew they were exceeding aircraft limits, but considered themselves able to safely do so.

The C-17 pilot is reported to have claimed that the stall warning and stick-shaker is inaccurate (C-17 test pilots disagree), and intended to ignore the stick-shaker during the display. Despite this, he was considered an excellent pilot, requiring very little supervision.

The B-52 pilot was a known ‘cowboy’, who had been performing increasingly dangerous airshow routines for years, and had taken this sort of flying into non-airshow flights as well, prompting complaints from junior officers. On one occasion, his B-52 cleared a ridge by just 30ft, and that after the co-pilot took the controls and pulled up!

Most pilots will certainly look at these cases and shake their heads. They would never be so stupid. But I suspect most pilots have, at some point, thought after a maneuver; ‘that wasn’t such a good idea…’ and hopefully taken more care in the future. That’s an important rung on the ladder of Airmanship. But most pilots probably don’t take it any further than that, denying themselves the opportunity to develop their airmanship further.  It’s hard to criticize them for that, however, they didn’t know to do anything more!

It appears to me that there is a gaping hole in our pilot training systems. We spend hours poring over the details of the operation of gyros (presumably in case we need to design and build one in flight), and are thoroughly tested on them. Yet Airmanship gets perhaps a brief mention in Human Factors, an exam question if you are very lucky, and a few tips from your instructor (who may have completed the training your are doing himself just a few months or years ago) as opportunity and example arises.

The majority of accidents today, by far, are blamed on pilot error. Most if not all of them could be linked to an Airmanship failure of some kind. Millions of dollars and countless hours have been devoted to improving aircraft and systems, and now we are finally starting to see progress in improving the human aspect of the equation. Most widely known today is probably CRM (Crew Resource Management), which itself has a come a long way in recent years. But this is just one part of the Airmanship puzzle (though a very important one), and may not be taught to pilots until they reach higher levels in their careers.

There needs to be a dedicated and thorough education of pilots in all aspects of Airmanship. Ideally, this would include theoretical examinations, separate and far beyond what exists today as Human Factors. It should also be taught in every briefing, in the cockpit, and in de-briefings. This will require additional training for instructors, as well, even if they themselves have completed the Airmanship training suggested above.

This is true for all levels and all kinds of pilots. The examples shown here involve military crews in heavy jets, but Airmanship spans all sectors of aviation. There is no doubt some excellent Airmanship training in some places, but if we are to improve the present statistics, this training needs to become universal.

For those wishing to learn more about Airmanship, I highly recommend Redefining Airmanship, by Tony Kern.