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Topic Title: Airplane disasters
Topic Summary: do we need an innovation to improve survivalibility?
Created On: 04 July 2009 01:32 PM
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 04 July 2009 01:32 PM
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tonysung

Posts: 630
Joined: 14 September 2001

In recent months, airplane disasters dominant news headlines.

The BBC link http://news.bb...1/hi/world/2008892.stm provides a timeline of recent airplane incidents. As the planes are flying at 30,000ft, there must be a brief moment that the pilots and passengers could act on order to improve the survival chances. The girl who survived the latest airplane accident is a vivid example that there is a small chance of surviving in an airplane accident.

Let's ignoring the cost at this moment but put forward some innovative ideas to develop ways to improve the chance of survival. E.g., to recover the plane from a free falling situation to a space-shuttle guilding position or other good ideas.

The IET can help to innovate and champion this.

-------------------------
Tony Sung
 07 July 2009 09:20 PM
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mbirdi

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The American and Russian space missions used Command Modules [housing astronauts] that were capable of parachuting back down to earth. I know that gliders were used to transport troops during WWII.

An aeroplane that's gone out of control at 30,000ft whilst travelling at 500 [or more] miles per hour is impossible to control either manually or through automatic systems.

I propose a combination of glider style design and parachute system. Simplicity in design and operation is what's going to save lives.

Edited: 08 July 2009 at 01:03 PM by mbirdi
 08 July 2009 11:10 AM
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sjeapes

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How about taking something from nature. The Samara(the helicopter style seeds from Maples seems like quite a need solution to slowing the rate of decent.

SpaceShip Two feathers its wings to perform a similar function on re-entry.


I think I'd rather concentrate on road deaths however as the actual rate of death is much higher that the comparatively safe air travel industry. Progress is being made but perhaps not at the rate it should.
 05 August 2009 06:04 PM
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dvaidr

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One would have thought that there could be a panacea for certain failure modes, but it's a huge request, (or huge ask as the illiterate fraternity say). Mankind will never eradicate the possibility of stochastic, catastrophic failure; he can only minimise the probability by using methods of risk mitigation. Unfortunately, this would increase life cycle costs, and the bean counters just wouldn't agree to it. There have been many innovations in the field of reliability engineering, including condition monitoring and predicitve maintenance and life analysis etc etc. but many of the financial backers and it has to be said senior management just want to see ROI. It's a sad fact of life, but that's how life is.
 27 August 2009 01:15 PM
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iie630326

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Originally posted by: dvaidr

he can only minimise the probability by using methods of risk mitigation. Unfortunately, this would increase life cycle costs, and the bean counters just wouldn't agree to it.


It is not just the bean counters; we are part of the problem. Are you prepared to pay more for your flights to go on holiday so that the airlines don't feel obliged to keep putting pressure on the regulators to keep increasing the periodicity for the maintenance of aircraft? Why do you suppose the cost of flights have come down in recent years?

If you are genuinely interested in what causes aircraft accidents then do a web search for "human error" and "human factors". I would recommend books by James Reason, like "Managing Maintenance Error: A Practical Guide"
and Sidney Dekker, particularly "Just Culture: Balancing Safety and Accountability".

The problems with when things go wrong it is in our instincts that someone is to blame and if we are involved we will look for a scapegoat. The truth is that all aircraft incidents is that a human error that can determined to causing the incident is, in fact, a sympton of a system that is an accident waiting to happen. The Alaska 261 flight was determined to be the jackscrew not being correct greased by a technician. However, the had increased the lubrication intervals from 300 flight hours to every 8 months; in case of Alaska 261 this was every 2550 flight hours. As the greasing wasn't done properly the the Alaska 261 went 5000 flight hours without greasing. Now the job of lubricating was done outside in pouring rain at 4 o clock in the morning hardly ideal conditions or time. So who is to blame is complicated because the system failed to ensure safety due to drift in the maintenance intervals.

-------------------------

Yours

Robert Miles, BSc(Hons), IEng, MIET
 30 October 2009 05:20 PM
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dvaidr

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I disagree.I never assume that someone is to blame and I have already mentioned stochastic failure which goes some way to supporting this. Materials fail through fracture, different corrosion mechanisms, work-hardening, and electronics failure is roughly exponential but can just as easily fail stochastically. A reliability engineer will never assume human failure or put in it's posh term, 'iatrogenic failure'.

And I am prepared to pay considerably more for a flight if it promises a safer journey.
 21 November 2009 09:55 AM
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JoanW

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Originally posted by: dvaidr

[...]

And I am prepared to pay considerably more for a flight if it promises a safer journey.


I presume you mean an even safer journey. Airlines are said to be amongst the safest means of travelling significant distances notwithstanding these incidents.

Some light and very light aircraft carry emergency parachutes which can bring the entire aircraft down at a non-fatal descent rate, but I've not heard of them being used for anything bigger than a four-seater.

Joan

-------------------------
JoanW
 21 November 2009 11:42 PM
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cmatheson

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A significant number of fatalities result from smoke inhalation while attempting to leave a burning stationary aircraft. This is because of the extensive use of certain plastics in commercial airliners.
In an evacuation from burning aircraft, you have about a 50% chance of getting out before axphyxiation. Perhaps a hard look at materials and escape systems would be the answer.

-------------------------
Chris Matheson MInstMC
 27 January 2010 11:16 PM
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Backintime

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 10 April 2010 04:32 PM
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Backintime

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 10 April 2010 04:58 PM
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westonpa

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It will be interesting to see what comes out of the investigation, i.e., human or equipment error or something else.

Regards.
 13 April 2010 09:32 AM
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Backintime

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To me it makes no difference whatever the cause of the tragic accident is. The statistical fact is, what everyone has accepted that, there is 99.?% certainty of fatality if such an incident occurs.

Surely any innovation to change this odd would be highly beneficial to the society and increase employment etc.
 13 April 2010 10:10 AM
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westonpa

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Originally posted by: Backintime

To me it makes no difference whatever the cause of the tragic accident is.

An 'engineer' should never close their mind and should always be concerned about differences, reasons, etc.
The statistical fact is, what everyone has accepted that, there is 99.?% certainty of fatality if such an incident occurs.

For this statement to be true everyone on planet Earth would have had to be questioned and given their relevant answer.....I for one have not therefore the statement is not correct. If you actually look at the stats instead of guessing then you will find that the overall percentage who die is less than 99%.
Surely any innovation to change this odd would be highly beneficial to the society and increase employment etc.
Manufacturers have been improving aircraft safety for decades and are still doing so but when the figures are already very good they have to be careful not to introduce changes which cause more problems than they solve.

I hope manufacturers continue to innovate and make air travel safer and I am happy that they continue the approach that is well established, i.e., design and test to get a good plane in the first place, monitor and maintain the plane always and thereafter investigate what went wrong and then look at what can be done to prevent it happening again. Therefore to me as an 'engineer' it does make a difference as to what the cause was.

Regards.
 13 April 2010 11:35 AM
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Backintime

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The improvement of plane design and elimination of human fallency are 'duty of care' the plane manufacturers and airlines standard safety compliance directives. That is well covered and I can't say anymore about it.

I see the innovation needed would be in case there are uncontrolled external causes such as lightning damage to disable the plane (like the Titanic was hit by an iceberg), can an innovative escape pod be developed to save the passengers inside the doomed bird - given that it has one minute or so to fall from the sky?
 13 April 2010 03:13 PM
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westonpa

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Good point about 'duty of care' and it would seem that for the most part plane manufacturers are on the ball. They are already trying different things to improve survivability but it then comes down to a risk benefit analysis. It's no good putting something on a plane, for example, which increases the chance of surviving a crash but at the same time increases the chance of a crash. Small changes to something which flies at 30,000 feet and at 600MPH and carries 500 people can easily increase the risk.

In relation to the Titanic for the most part that was caused primarily by error in human decisions of the time and secondly by the technology of the time.

"given that it has one minute or so to fall from the sky?"

The majority of plane crashes do not start from 30,000 feet because they are generally just after take-off or when coming into land, as was the Polish crash, and thus many people die in fire's.

Regards.
 13 April 2010 05:50 PM
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Backintime

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Hymm, so, as an engineer, seeing the risk is there for everyone who flies. Know (hopefully) most of the in's and out's (take-offs, landing, mid-air malfunction etc) about the risks and hazards.

Should we seek some innovative ways to do something about it, or we just carry on business as usual until ... ...?
 03 May 2011 12:42 AM
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victor15

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I have seen the aerospace industry downsizing its workforce in recent times due to the influx of automated manufacturing sytems, subcontracting an sophisticated computer design programmes. Nowadays a design concept of an aero engine can be put into production in two to three years. This type of development would have taken 12 or even 20 years in the past. However I have seen a decline in individual component testing. This is now left to computer programs and an mathmatical predictions so in some cases a component is never tested until the engines initial test runs on a test bed. whereas a skilled test engineer would have tested components to destruction in the past.

Is this really the safest way of operating, just to save time and money?
 03 June 2011 07:38 PM
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ProductDesign

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Joined: 02 June 2011

Although air travel is statistically safe, I don't fly so easy knowing how many components are involved and understanding the amount of flight hours a system is commercial used for in order for it to be profitable. With the flight data on the Air france Flight 447 coming to light recently, I took to looking at what Aviators had to say about this problem of deep stall. It seems to me the Aircraft was getting inconsistent speed data which informed the junior pilot to pull up instead of push the nose down. In short the the feel for the aircraft isnt there at this speed in the dark and so potentially reliance on the advance systems of the Airbus guided the pilot to do the wrong thing. I may be wrong here as i have not seen anyone else draw the same conclusion. the mode of the crash then was a deep stall which would only have been avoided ( as they were at peek alt of 38,00Ft ) by a tail mounted chute or something to bring the nose down. They would have had 3 minutes to gain lift and avoided incident. Could something as simple as a GPS based speed reading instead of the reliance of the one source of airspeed, helped the pilot see the bigger picture. I think judging by his stick inputs he may have been getting an overspeed reading, at least I heard mention of this in the early days after the crash. If this wasnt the case then the pilot it entirely to blame for putting the aircraft into a stall. Though in the subject of this thread, should Airbus now be designing aircraft that you simply can not put into this kind of stall? Surely the onboard computers can overide the passive stall warning when they see a 10,000 / Min decent ( when the attitude of the aircraft is nose up 15 deg plus ) If the control surfaces are not sufficient in this instance to break the stall, when they had full thrust, then could it be argued that the engines are underpowered?

Welcome anyone's comments, though I know this is an old thread!

Chris

Product Design

Edited: 03 June 2011 at 07:46 PM by ProductDesign
 05 June 2011 05:15 AM
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pria22

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Joined: 30 May 2011

I am sure everyone is aware of recent airplane disaster in delhi!That was insane!

flex ticket
 08 June 2011 10:12 AM
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d80s22

Posts: 8
Joined: 08 May 2002

Originally posted by: ProductDesign
Could something as simple as a GPS based speed reading instead of the reliance of the one source of airspeed, helped the pilot see the bigger picture.


This wouldn't work - GPS gives ground speed and what pilots need is airspeed.

There are a lot of unanswered questions about the AF447 crash, hopefully the accident investigation will answer them.

Robin.

-------------------------
Dr Robin Collings MIET
IET » Transport engineering » Airplane disasters

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