An explosive depressurisation is one which occurs in less than half a second. This type of decompression usually only occurs in small aircraft flying at very high altitudes. Decompression which occurs this rapidly, at a rate which is greater than the rate by which the lungs can decompress, is likely to cause lung damage. For a specific size of pressure hull breach, the likelihood of the rate of decompression reaching a level where lung damage is possible decreases with an increase in the overall size of the pressure hull. ---Case now closed---
"The FAA said in a directive that the decision to ground all 737 Max 9 planes stems from "a report of an in-flight departure of a mid cabin doorplug, which resulted in a rapid decompression of the airplane," referring to the Alaska Airlines incident." Rapid decompression Rapid decompression typically takes more than 0.1 to 0.5 seconds, allowing the lungs to decompress more quickly than the cabin.[1][6] The risk of lung damage is still present, but significantly reduced compared with explosive decompression. https://en.wikipedia.org/wiki/Uncontrolled_decompression So if the FAA classified it as that... there ya go. But all that aside... I'm not going to argue with you about Constitutional Law, and we can have lots of light hearted debates about long term market direction... but in this case, don't argue with me about fluid dynamics and the volume of air in an enclosed space escaping an opening that bridges a pressure differential between that space, and a significantly lower pressure on the other side of that space. Now... with all that said, if I wanted to continue this, I certainly could spell it all out with the formula's as applied to fluid flow. Basically, it's the integral of dp/dt. Where p is pressure and T is time. That equation is taken to the second order with dv/dt that has a multiplier in there based on the hole size and the viscosity of air, which is nil. And the point is... that hole was so big, there's no use to even looking up the formula. To make my point... a kid had his shirt ripped off by the airflow. Do you think that happens on a slow leak? For lack of a better analogy... this is not a nail in a tire B1. It's more like a pin in a balloon. These people were lucky this happened at 16,000 feet. Had this happened at cruise altitude, there'd be a lot more lawsuits, because there'd be a lot more seriously injured people. Now... I'm not going to argue fluid dynamics (in this case air) and the calculus formulations behind a volume of said air in an enclosed vessel---passing thru an opening of a defined size, but trust me, perhaps it wasn't "milliseconds" as I wrote, but it wasn't much more. Cabin pressure in a commercial airliner is a linear ascent up to 8000 feet. At 41,000 feet, the physiological effects on the passengers is the same as if they were scaling Mt Fuji and were camping out at base-camp 8000. Again, in this particular incident, at 16K or whatever it was... more than likely hypoxia would not be a problem. But that is not the point, the point is, there WAS a rapid decompression. This is a defined term. And the onset of hypoxia doesn't give a rats ass about the type of airplane. The fact that it can happen in small aircraft is not material to the debate here. If it's some pos 40 yo twin engine that has been shoddily maintained with the bare minimums to fly legally, well yeah, stuff happens. But if the pressure inside is ambient, and if you're above 20K... you're screwed if you stay there for more than a minute or so. That's why there are drop down masks... ----- And that Boeing had ambient pressure in less than a minute tops. I don't even have to crunch the #'s, it's not even close. And had that blown out at cruise, it would have been categorized as an explosive decompression. ~case closed.
B1 that is not true. At 35,000 feet, the onset of hypoxia and lack of useful consciousness is less than 1 minute. Ya know... I have better things to do.... but damn it, hold on....
Thank you for the extra effort. You have now come around to agreeing with all of my points. The case was closed a few posts back. Plenty of time for the pilots to don masks. ---Not so much in a small airplane as the air pressure becomes equal much much more quickly.
Ok B1.... you asked for it... Read that again B1... and read it real slow. ---> What happened on this flight falls into the category of "extremely improbable". So case closed on that. Now in one of my follow up posts I spoke of the formulas required to calculate the time required for a pressurized container to reach ambient pressure if the walls of that container are somehow breached. As I pointed out, those are pretty complicated calculations, which require first order differential equations based on volumes, hole size, ambient temperature, viscosity, Boyles Law of expansion and ∆P. Those results must then be inserted into a second order differential equation and solved for ∆T. That was of course off the top of my head, so for fun I included one that would need to be solved below, but these formulas are for engineers that require gnat's ass accuracy--- like in nuclear power-plants. And this is only one of the formula's required. But B1 we don't need to do all that. I can spell it out for you in layman's terms that perhaps you'll understand, because I figured out a simple way to make my point here. In an aerosol can, the pressure difference between the inside of the can and atmospheric pressure is 2X-8X Lets use 5X --- it's in the middle. Now... lets look at pressure differential inside our jet at 16,000 feet. Lets use 4.0--- close enough. And amazingly close to our spray can. Now look at this picture at the size of that opening Now picture that fuselage as an aerosol can of hairspray. That hole is pretty big relative to the can right? Right. Now go into your bathroom and grab a can of hairspray. Find the nearest screwdriver, and punch it thru the side of that can. See how fast it depressurizes. Yeah. Pretty darn quick isn't it? And that's exactly what happened to Alaska Air. It was such a violent decompression, one of the I-Phones they found... (it was being charged)... not only did it get sucked out... it took half the plug with it! Now go get that can of hairspray and a screwdriver. Make sure you where safety glasses. ~vz ~CASE CLOSED
Ahhhh. I dunno. I've argued with B1 several times about the Constitution and he proved me wrong every time. Admittedly though, that's not that hard to do. Not my wheel-house. And... he's made two of the greatest long term ES calls I've ever seen. Not a few percentage points, perfect bottom calls that were good for over 1000+ points. B1's stubborn though, when he states a point, you might as well be arguing with a stop sign, because neither will change. That said, if he wants to argue math and science with yours truly, he better bring more than the cheap plastic knife that you find at a 4rth of July picnic to that dual. Ain't that right B1(?)... ~case sealed.
he / she is an ultra stubborn magatard - living in a parallel universe. would probably die for the orange assclown.