::[ kampungkai ]::

Sunday, October 1

Emergency Slide-Raft

Sunday morning rain is falling
Steal some covers share some skin (I like that)
Clouds are shrouding us in moments unforgettable
You twist to fit the mold that I am in (oh)

ahhh beautiful day, Maroon 5's Sunday Morning playing in the background as i start my new entry of the week.

Ever thought how it would feel like being in a fire-drill on an aeroplane? Emergency doors deployed, cabin crews screamin/directing at the top of their voice, babies' crying..... everything in CHAOS.

Since an aeroplane is nothing less than 1 storey high from ground, u would fall to death, or break your bones if u were to jump off. That's where the inflatable emergency slides come to use.

Of course we wouldnt hope for one to be deployed. It would be so much better to walk slowly and gracefully off the main door and into the aerobridge, rather than sliding down and running on the tarmac to be greeted by firemen or SWAT team.

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The slide-raft on every exit door is inflated with compressed gas. And these tanks shown here are used to store the gas. It is made of aluminum allow and wrapped with carbon fibre/fibre glass. It has a life span of 15 years and is colored orange(old) or white with orange band(new).

But why is it called slide-raft? because, it can be used both as a slide and a raft. But not all aeroplanes are fitted with slide-rafts, smaller planes are normally equipped with slide only, because they seldom travel over oceans.

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Hydrostatic Test

Every 3 years, these tanks would be removed from the aeroplane to be inspected, discharged, service, and recharged. As usual, aroplane parts are always related to safety, therefore frequent checks need to be done to make sure of its servicability, even though it is in good condition.

After the tanks have been discharged, they will undergo a Hydrostatic Test(HT), whereby the reservoir is pressurized with extremely high pressure in a water jacket to check the expansion of the reservoir. If the expansion is within limit, good. But if the expansion is out of limit, scrap the bottle.

After HT, the bottles are dried with warm air. Then, it is recharged in a cage, as shown in the above pic.

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Charging weight

Nitrogen(N2) & Carbon dioxide(CO2) are charged into the bottle with a specific ratio, depending on aeroplane model. As for the high-tech Boeing 777, they even include Helium into the bottle, i dunno why.

So, charging quantity is determined by the weight of the bottle rather than volume/pressure (temperature varies volume & pressure, so it would be inaccurate). Let's say we charge the bottle with CO2 first, so once the digital weighing machine reads the required weight, then we'll continue with N2 charging until the needle on the gauge reaches the green band.

It would take approximately 90-120 minutes just to charge 1 bottle. But when deploying the whole slide-raft, it only takes 6 seconds to discharge.

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This is where the slide-rafts are being tested and check for leakages and servicability. It is humongous. Can be 10-15m long & 4-5m wide. Inflated with so much air to make sure it floats on water.

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Test area

This is how the slide looks when it is deflated, just like a baloon. As it is packed into the door assembly, it is nicely folded in a proper manner, just like folding a parachute. Or else, it wouldnt deploy nicely or it might get stuck.

There are 12 doors on a Boeing 747-400, which also means 12 slide-rafts. All these slide-rafts are inflated using 2 reservoirs + ambient air within 6 seconds.

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A door full with technology

See the buldge at the bottom of the door? that's where the slide-raft & reservoir is stored. Looks neat, but it can be a life-saver.

By the way, only cabin crews get to simulate jumping off on the slide-raft. I've never tried jumping off the plane on a slide, and there wont be a chance unless if it is a real-case-scenario. It would be too time-consuming and troublesome and expensive to run a fire-drill.

Well, it aint that hard after all, just pull the trigger on the door and u can slide off hahahah! but i wouldnt teach u how, for


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