Tuesday, May 29, 2012
Wednesday, May 16, 2012
Airplane Black Box
Built to Survive
In many airline accidents, the only devices that survive are the crash-survivable memory units (CSMUs) of the flight data recorders and cockpit voice recorders. Typically, the rest of the recorders' chassis and inner components are mangled. The CSMU is a large cylinder that bolts onto the flat portion of the recorder. This device is engineered to withstand extreme heat, violent crashes and tons of pressure. In older magnetic-tape recorders, the CSMU is inside a rectangular box.
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Using three layers of materials, the CSMU in a solid-state black box insulates and protects the stack of memory boards that store the digitized information. We will talk more about the memory and electronics in the next section. Here's a closer look at the materials that provide a barrier for the memory boards, starting at the innermost barrier and working our way outward:
- Aluminum housing - There is a thin layer of aluminum around the stack of memory cards.
- High-temperature insulation - This dry-silica material is 1 inch (2.54 cm) thick and provides high-temperature thermal protection. This is what keeps the memory boards safe during post-accident fires.
- Stainless-steel shell- The high-temperature insulation material is contained within a stainless-steel cast shell that is about 0.25 inches (0.64 cm) thick. Titanium can be used to create this outer armor as well.
There are several tests that make up the crash-survival sequence:
- Crash impact - Researchers shoot the CSMU down an air cannon to create an impact of 3,400 Gs (1 G is the force of Earth's gravity, which determines how much something weighs). At 3,400 Gs, the CSMU hits an aluminum, honeycomb target at a force equal to 3,400 times its weight. This impact force is equal to or in excess of what a recorder might experience in an actual crash.
- Pin drop - To test the unit's penetration resistance, researchers drop a 500-pound (227-kg) weight with a 0.25-inch steel pin protruding from the bottom onto the CSMU from a height of 10 feet (3 m). This pin, with 500-pounds behind it, impacts the CSMU cylinder's most vulnerable axis.
- Static crush - For five minutes, researchers apply 5,000 pounds per square-inch (psi) of crush force to each of the unit's six major axis points.
- Fire test - Researchers place the unit into a propane-source fireball, cooking it using three burners. The unit sits inside the fire at 2,000 degrees Fahrenheit (1,100 C) for one hour. The FAA requires that all solid-state recorders be able to survive at least one hour at this temperature.
- Deep-sea submersion - The CSMU is placed into a pressurized tank of salt water for 24 hours.
- Salt-water submersion - The CSMU must survive in a salt water tank for 30 days.
- Fluid immersion - Various CSMU components are placed into a variety of aviation fluids, including jet fuel, lubricants and fire-extinguisher chemicals.
Black boxes are usually sold directly to and installed by the airplane manufacturers. Both black boxes are installed in the tail of the plane -- putting them in the back of the aircraft increases their chances of survival. The precise location of the recorders depends on the individual plane. Sometimes they are located in the ceiling of the galley, in the aft cargo hold or in the tail cone that covers the rear of the aircraft.
"Typically, the tail of the aircraft is the last portion of the aircraft to impact," Doran said. "The whole front portion of the airplane provides a crush zone, which assists in the deceleration of tail components, including the recorders, and enhances the likelihood that the crash-protected memory of the recorder will survive."
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Tuesday, May 15, 2012
Mazha Thornnathariyaathe...
Neram para para velukkunnathe ullooo… Appu mon entho innu valare nerathe eneettu..
ammayude arikilekku chennu.. amma yum ennettathe ulloo..adukkalyil entho paripaadikal aanu.. appu clockilekku nokki..samayam 6.10.
Ayalpakkathe veetil ninnu radio yiloode “prabhaatha geetham” oru neratha sabdhathil kelkkam...ambalathile paatinu appu vinte veedu vare ethaanulla sheshi illa..purathuthinnu kilikalude kala pila shabdam kelkkan thudangi..
appu oorthu..ee kochu veluppan kaalathu pashukkidaavukalude karachilum....kilikal ira thedan pokan thirakkukoottunnathum oke etra manooharam…. prakruthiye athinte sarvva iswaryathodum koode thanne aanu daivam srustichirikkunnathu ennu appu manasil oorthu..
palluthechu..chaya kudichu muttathekku irangan neram amma paranju:
" Appooo...mazha varunnunduu...purathekkonnum pokanda..."
Appuvinu pryaayam verum 12 vayasu. oru 12 vayasukaarante ella kusruthiyum kallatharangalum appuvil niranju thulumbi ninnirunnu..
koottukarkkum veettukarkkum avan verum appu alla; ‘appukkuttan’ aanu..!!
appu muttathirangi melottu nokki. neram veluthu enkilum ..muttathonnum athra velichamilla..pakal aayenkilum sooryane kaanan polum illa..engum oru modal matram..
ini sooryan kadalil ninnu pongi vannille..? .atho aarengilum sooryane thadanju vachirikkukayaano...? ennokke yulla kochu kochu samsayangal manasilloode paayave...pettannu oru mazhathulli appuvinte kavilil ummavachu..!!!!
Amma paranjathu nera ...daa mazha varunnu..appu manasil oorthu..
" ammeee..mazhaaaaa…….” ennu parajukondu..appu veedinullikku oodi
amma kodutha oru glass choodu kattankaappi melle kudichu kazhinjappolekkum ...mazha thimirthu peyyan aarambhichirunnu…
Appu purathekku nokki... mazha thannam pinnam peythukondeee irunnu…muttathum parambilum oke vellam kuthichozhukunnu..Ithokke kandappol appu vinte manasil oru agraham potti mulachu..mazhayathu irangi nananjalo…..??
amma vazhakku parayum ennu appuvinu ariyaam..thala pukanju aalochichu appu athinu oru soothram kandu pichichu..
Enthaanu aa sootram ennalle..?
muttathu kettiyirikkunna aattin kuttiye sootrathil azhichu viduka..
ennittu ammayodu paranjittu athine pidikkan mazhayilloode ooduka..
mazhayum kollam..adineyum pidikkam. appu sootrathil chennu aattin kuttiye kettiyirunna kayar azhichu vittu.. aattin kutty muttathekku irangi ninnu..
“ammee ammee..... aadu kettu azhichu…. Dha… muttathu vannu nilkkunnu…”
appu vilichu koovi..
“Ni athinte onnu pidichu kettada....ennittu vegam kayarane..mazha adikam nanayanda...pani pidikkum…..” oru upadeshathode ammayude sammatham appu vinte pocketil…!!!!!!!!
Appu pathiye mazhayathekkirangi.. aadhyathe 8-10 mazha thullikal appuvine ikkili ittu....
adutha thullimuthal appu mazhayumaayi changatham koodi.. aadine pidikkanenna vyajena appu mazhayathu chaadi thimirthu… vellam theruppichum...thullikkalichum oke appu mazhayathiu adichu polichu..
Appozhaanu appu aadine patty oorthathu.. ayyo...adine pidichillenkil.........?????
ammayude kyil irikkunna chooral manasil thelinjathe ullo..appu vinte bodham poyi..
“evide ee nasham pidicha aadu?” thaan kuzhicha kuzhiyil thaan thanne veezhumo?
appu aadine thedi nadannu...athaa adu adutha parambil nilkkunnu..
appu aadinte aduthekku oodi chennu..appu vine kandathum ..aadum oodi
randu veerum oodeda ottam..aattin kutty munnil ..appu pinnil…
paadathum parambathum appuvine escort aakki...aadum oodikkalichu!!!
Mazhayude sakthy pathukke kurayunnathu appu sradhichathee illa..
appuvinteyum aadinte yum oottam kure neram neendu ninnu..
onnu randu thavana appu cheliyil veenu..oru thavana kaalu thenni paadathu veenu..
Veenittum athonnum vaka veykkathe appu oodikkondeee irunnu................
mazha thornnathariyaathe..............................!!!!!!
shubham..
The End!
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