Baseless aircrash speculation

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shpalman
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Baseless aircrash speculation

Post by shpalman » Sat Jan 09, 2021 5:42 pm

Sriwijaya Air Boeing 737

It's an older model, a 737-500, so nothing to do with the problems the MAX had. The profile wouldn't fit anyway: it appears to have basically fallen out of the sky having reached about 10,000'.

Explosive decompression due to metal fatigue?
molto tricky

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Martin Y
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Re: Baseless aircrash speculation

Post by Martin Y » Sat Jan 09, 2021 6:47 pm

Explosive decompression isn't likely at 10,000 ft.

Don't high altitude flights typically allow cabin pressure to drop to about 8-10k feet equivalent?

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dyqik
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Re: Baseless aircrash speculation

Post by dyqik » Sat Jan 09, 2021 6:50 pm

Martin Y wrote:
Sat Jan 09, 2021 6:47 pm
Explosive decompression isn't likely at 10,000 ft.

Don't high altitude flights typically allow cabin pressure to drop to about 8-10k feet equivalent?
8k usually, which is about 75% of an atmosphere, or about 1.2 psi pressure difference at 10k feet. If that didn't happen, it's a ~5 psi over pressure at 10k feet.

Typical pressure differences between 8k ft and cruising altitude are ~7-8 psi, so even with a failure to lower the pressure, the pressure difference is 2/3 of the nominal design value.

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shpalman
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Re: Baseless aircrash speculation

Post by shpalman » Sat Jan 09, 2021 6:59 pm

True that there shouldn't have been that much of a pressure difference at 10,000'. The cabin altitude needs to be maintained at 8,000' or below on commercial flights, but that's relevant when at cruising altitude.

We recently had a 737-700 suffer decompression due to an uncontained engine failure, but not in a way which was catastrophic for the airframe.
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