Title: Electrical Problems May Have Sparked Swiss Air Flight 111 Crash * Pictures Taken from Web Site (http://www3.ns.sympatico.ca/mr.187/photos.html)
1Electrical Problems May Have Sparked Swiss Air
Flight 111 Crash Pictures Taken from Web Site
(http//www3.ns.sympatico.ca/mr.187/photos.html)
- Urs Zimmermann (Pilot) and the planes flight
recorder. - The exact cause of the crash is unknown, however,
evidence points towards a rapid and deadly
electrical fire
2Rapid Fire Pictures Taken from Web Site
(http//www3.ns.sympatico.ca/mr.187/photos.html)
- According to record Zimmerman noticed smoke at
approximately 10,000m and 16 minutes later, the
plane slammed into the Atlantic Ocean off Peggys
Cove, N.S. Canada. - According to Susan Bradley, a spokeswoman for
Boeing, Kapton was the primary coating on the
wiring in Swissair Flight 111 (Macleans Sept 21,
1998 v111 n38 p20(1))
3How Safe is Kapton WiringPicture taken from web
site (www.ece.msstate.edu/hvl/research.html)
- Patrick Price (Expert with the former Boeing Co.
in Seattle) on Kapton wiring - Its like taking an incendiary bomb on board
(Macleans, Sept 21, 1998 v111 n38 p20(1)) - In 1982 the U.S. navy stopped using Kapton wiring
in jet fighters when cracks in wires coated with
Kapton were linked to on-board fires.
(Macleans, Sept 21, 1998 v111n38 p20(1)) - Scientists have found Kapton is prone to rare but
catastrophic arc tracking when the wire is
subjected to chafing, vibration, and moisture.
U.S. News and World Report, Sept 28, 1998 v125
n12 p44(1)) - If a wire cracks, electricity can arc to nearby
material, setting it on fire. This is known as a
flash over which burns at a searing 1,000 C.
4Deadly Games
- Swiss Air Flight 111 had approximately 240 km of
wires running through it to bring passengers a
premium video and gambling system in todays
intensely competitive market for business and
first-class flyers. - Each seat aboard Swiss Air Flight 111 had a video
screen that pops out of the armrest like a tray
table. Passengers could play video games, music,
or even gamble. - It was this luxury which could have lead to the
crash. - The system costs about 2 million or more dollars
per plane and was developed by Interactive Flight
TechnologiesTM. A struggling company which said
it wants out of the in-flight-entertainment
business. - This web of wires from each seat to central
computers aboard the plane generates a greater
possibility for an electrical disaster. (Time,
Nov 9, 1998 p58(1))
5Advanced Kapton Material is Being Used Today
- Since 1993 Kapton has been improved by wrapping
it in a tough Teflon coating. - In an article I found from 1998 FAA officials
said that old forms of Kapton may soon be removed
from hundreds of planes. - Boeing company spokesman John Thom said that
Kapton was and is certified for use on
commercial airplanes (Macleans, Sept 21, 1998
v111 n38 p20(1))
6Some Pictures from the aftermathPicture taken
from web site (http//www3.ns.sympatico.ca/mr.187/
photos.html)
- At left is one of the most recognizable photos
from the tragedy as rescuers try in vain to find
survivors. Pictured at right is the Emergency
Service Paying tribute to Flight 111
7Fire Prevention in PlanesPicture taken from web
page (http//www.airliners.net/open.file?id13250)
- The Federal Aviation Administration or FAA
announced in October of 1998 that Mylar
insulation used in nearly 12,000 passenger jets
must be replaced to reduced the chance of fire.
(U.S. News and World Report, Oct 26, 1998 p17(1)) - It is believed that this type of insulation was
set ablaze by a short circuit in the electrical
equipment aboard the Swiss Air Flight 111
8Luxury isnot alwaysbetter Picture from web site
(http//www.tsb.gc.ca/ENG/TSB_Investigations/Swis
sair/)
- The high tech video system aboard Flight 111 used
Microsoft Windows NT software, with wires
connected to a central computer. (Time, Nov
9,1998 p58(1)) - Investigators found that the wires had been
connected to the same electrical pathways that
powered vital parts of the aircraft. - Therefore, if there is a problem with the video
system, then there is a problem with the whole
plane. - In the future this type of video system should be
connected to a separate area of the plane where
vital networks in the plane will not be affected
thus buying time for an emergency landing.
9Firefighting Training for Pilots and
PreventionWeb site (http.www.tsb.gc.ca/EN/TSB_Inv
estigations/Swissair/site_pages/saf/FireRecs_2000
dec4.ht)
- The investigation into Swiss Air Flight 111
revealed safety deficiencies in crew training and
awareness, and procedures related to in-flight
firefighting. - The TBS safety board issued the following
recommendations to address safety deficiencies - A lack of a coordinated and comprehensive
approach to in-flight firefighting. - Smoke/fire detection and suppression systems are
insufficient - There are no smoke/fire detection and suppression
systems in the cockpit or cabin or any area not
considered a fire zone. - The importance of making prompt preparations for
a possible emergency landing is currently not
recognized. - This is due to company policy and the feeling
that it is an inconvenience. - Access to critical areas within the aircraft are
inadequate. - There has been little or no training provided to
aircraft crew on how to access areas behind
electrical or other panels
10Material For Fire Prevention
- Halon (Washington Monthly, Sep 1997 v29 n9
p44(2)) - Pressurized bottles of Halon a highly effective
fire fighting agent have long been used in the
cargo holds of larger jets but is not used in
smaller planes - Brings us to the fact that in general the larger
the vehicle the safer it usually is due to
greater regulations. - A Plastic Called PHA (Discover, August 1999 v20
i8 p11) - PHA is a plastic which only emits water vapor
when it burns, and it brakes down into a
flame-resistant compound. - There is also the possibility of Flame Retardant
Material (Class Notes) - Chlorine and Fluorine when added to material help
in fire resistance. - Trade off would be the hazardous smoke this type
of compound produces when it does burn. - Flash overs due to electricity arcing burn at a
searing 1,000 C.
11Crash StatisticsLarger The Vehicle the Safer
- Some airline safety facts (Web Site
(http//www.air-transport.org/public/speeches/view
1997.asp?UniqueID38)) - You are more likely to die by being kicked to
death by a donkey than in a plane crash - You are more likely to be crushed by a falling
object - You are much more likely to be killed by your
spouse - You have one chance in about 7 million from dying
in an plane crash
12Average TimeTo React To A Fire(http//www.nifc.
gov/gallery/manter.html)
- The average time between when an in-flight fire
is detected and when the aircraft either ditches,
conducts a forced landing, or crashes is about 17
minutes. (http//www.tsb.gc.ca/ENG/TSB_Investigati
ons/Swissair/site_pages/saf/FireRecs_2000dec4.ht)
- Some examples
Type Date Minutes
AN-12 1967 lt10
B-707 1973 7
B-747 1987 19
MD-11 1998 20
13Increase Your Chances
- Handy Hints For The Nervous Traveler
(http//www.amigoingdown.com) - 70 of incidences in recent year occur on
take-off or landing - Try to book non-stop flights
- Take note of where the nearest emergency exit is
- Choose a large aircraft
- The larger the vehicle the better your chances
14Does Fate Alone Decide Who Survives
- Most Likely No
- 71 of the people who die in crashes die after
the plane comes to a compete stop. (People
Weekly, Oct 20, 1997 v48 n16 p125(3)) - You can increase your chances by knowning your
surroundings - How many isles to the exit
- In case of fire if you can hold your breath for
30 seconds thats how long it takes to exit the
aircraft normally. - Dont try and get your duffel bag in case of a
crash - Pay attention to the safety procedures (life
vests)
15Where To Sit(http//www.aircrash.org/burnelli/)
- If youre worried about impact (People Weekly,
Oct 20, 1997 v48 n16 p125(3)) - Sit in the back
- If youre worried about a fuel fire
- Sit forward of the leading edge of the wing
- If your worried about the plane breaking up
- Sit by the over-wing exits
- This is the strongest part of the aircraft due to
the fuel being carried in the wings
16Improved Electrical Apparatus Insulation Material
- One way to improve Wiring in planes is to use an
improved insulation material - Currently many electrical wires use porcelain and
glass insulators - An ethylene and vinyl acetate copolymer (EVA)
tested better in the lab these forms of
insulation (Polymer Engineering and ScienceJul.
1996, V.S. Ivanov, I.I. Migunova, N.A. Kalinina,
G.N. Aleksandrov) - As discussed in class copolymers usually increase
a materials ability to withstand an impact - Copolymers would help in wires that would be
subjected to rough conditions - Kapton currently has problems under rough
conditions
17Radiation-Induced Current (ChemAbsStudent,
Studies on radiation-induced current in
polymeric insulating materials and their fine
sturcture, J. Master. Sci 17 no 10 (1982)3052-6)
- Degradation in crystalline materials such as
Polyethylene - Degradation in non-crystalline materials such as
ethylene-propylene rubber used for wire
insulation - For radiation-induced current degradation is
affected more by the degree of crystallinity than
its perfection.
18Method For Improving The Environmental
Stress-Crack Resistance or (ESCR) (J. Appl. Poym.
Sci. 16, no 9 (1972) 2375-86)
- (ESCR) is a critical factor in wire insulation
- In studying the effect of rubber on (ESCR) the
choice of a base resin is important - Depending on the resin and rubber combination you
choose the (ESCR) can double or increase by
50-fold. - Kapton could be improved with slight variations
in its production and perhaps different types of
resins should be looked at - For example
- The higher the molecular weight of
Polyisobutylenes the more effective its
performance as a stress crack additive
19Polymers Good Insulators
- Polymers are good insulators because they are
covalently bonded and their electrons are all
tightly bound.
20Polymers Conductors!?
- Doping of polymers with strong electron acceptors
such as iodine can cause polymers to conduct
nearly as well as metals. - Doping to polyacetylene causes its conductivity
to be 1010 times higher than pure
polyacetalylene.
21Polymers - Good Conductors!?
- This flexible electronic circuit functions even
when its bent. - http//focus.aps.org/v6/st18.html
22Uses of KAPTON - Properties
- Maintains its mechanical stability at very high
and very low temperatures - resists high mechanical stress during assembly
operations - has excellent electrical insulation and thermal
properties - has outstanding resistance to most chemicals,
lubricants and fuels - allows space and weight savings
23Uses of KAPTON - Electronics
- In electronic equipment, KAPTON is used as
substrate material for Flexible Printed Circuits
and punched, bonded or formed high performance
part in small miniature switches. It can be
etched in alkaline solns. - Bar Code Labels
- Heat Sinks, to ensure optimal heat transfer
between film and power transistors - Masking tapes
24Uses of KAPTON - Bondable Application
- Can be bonded, coated or laminated to allow the
following requirements - Belts
- Thermal insulator in irons
- Fuel sensors
- Smoke hoods
- Blood bags
25Uses of KAPTON - Electronic Insulation
- Wire and cable insulation
- formed coil insulation of traction motors
- Magnet wire insulation
- transformer and capacitor insulation
26Uses of KAPTON - Automotive
- Alternator heat sink insulator pads
- Air bag (diaphragm)
- Flexible circuits
- Spark plug boot
27Uses of KAPTON - Aerospace
- Cockpit sun shade
- Speakers
- Flexible Curcuitry
- Acoustic insulation
- Thermal blankets
28Uses of KAPTON - Thermal Management
- Heat sink
- Power supplies
- Heater circuits
- Copier belts
- Carrier belts
- Coil insulation
29Thermal Degradation Experimental Methods
- Thermogravimetry(TG)-measures loss in weight
- Differential scanning calorimetry(DSC)
- Differential thermal analysis-heat absorption or
evolution due to either physical or chemical
changes occurring within the polymer is measured
30Thermal Degradation Reactions
- Depolymerisation Reactions
- Characterized by the breaking of the main polymer
chain backbone so that at any intermediate stage
the products are similar to the parent material
in the sense that the monomer units are still
distinguishable. The ultimate product may be
monomer.
31Thermal Degradation Reactions
- Substituent Reactions
- It is the substituents attached to the backbone
of the polymer molecules which are involved so
that the chemical nature of the repeat unit is
changed although the chain structure may remain
intact. - See reaction example, page 24
32Radical Depolymerisation Reaction
- Degradation Reaction example
- Poly(metyl methacrylate)
- Between 300-400 oC, see example
33Oxidation of Polymers
- Degradation of polymers usually increases in the
presence of oxygen - R O2 ? ROO
- ROO RH ? ROOH R
- Termination
- 2R ? R-R
- R ROO ? ROOR
- 2ROO ? ROOR O2
34Photo-degradation
- Wavelengths of light from sun range from infrared
(gt700nm) to the visible spectrum (400-700nm) to
ultra-violet (lt400nm). - Energy of 700nm photon is 170 kJ/mol and energy
of 300nm photon is 390 kJ/mol - Strength of C-C and C-H bond are 420 and 340
kJ/mol respectively - It is clear that the energies of the UV and
possibly the visible components of sunlight are
sufficient to break chemical bonds