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NovaBlast
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Say that all the engines of a boeing 737 failed while it was 12.496km in the air and fell into freefall, what would its terminal velocity be and how long would it take to hit the ground
What do you mean by "freefall"? Flat spin? Nose down streamlined? Tumbling? What is your motivation for asking this question?NovaBlast said:Summary:: what's the terminal velocity of a boeing 737 in free fall after the engines have failed, from 12.496km, and how long would it take to hit the ground?
Say that all the engines of a boeing 737 failed while it was 12.496km in the air and fell into freefall, what would its terminal velocity be and how long would it take to hit the ground
There’s no such thing - “free fall” and “terminal velocity” are mutually exclusive.NovaBlast said:what's the terminal velocity of a boeing 737 in free fall
The scenario isn't just odd, it is poorly defined and not physically realistic. Just having engines fail doesn't cause an airplane to fall in freefall, and the descent rate depends entirely on the orientation. E.G., is it gliding, diving or stalled?NovaBlast said:Say that all the engines of a boeing 737 failed while it was 12.496km in the air and fell into freefall, what would its terminal velocity be and how long would it take to hit the ground
And on the other side of the coin is Air France 447, which stalled, fell out of the sky and crashed with little forward speed and the engines at full throttle.Filip Larsen said:Also, its not uncommon that even passenger jets, which are normally supposed to operate with their engines on at all times, can be glided to a (more or less) safe landing in case of engine outage.
Especially the 737.Nugatory said:I would not surprised to find that the airframe breaks up before that terminal speed is reached.
Vanadium 50 said:And the oddly specific height?
This is inevitable. However, I would be interested in the rocket that put the 36 tons up there. That's 50% above what a space shuttle could launch.NovaBlast said:Say that all the engines of a boeing 737 failed while it was 12.496km in the air
Not in aviation we don't, such errors would be... unfortunate . Even a Lufthansa flight at that altitude would report flight level (FL) 410.fresh_42 said:Yes, I got lost in translation, sorry. We use points to separate the three digit packages and commas as decimal separator.
Sure. I wouldn't have made the mistake if it was 41,000 ft. But it was 12.946 km, which isn't used in aviation. I normally recognize it, but once in a while I slip, seduced by the imagination of a B737 in space.pbuk said:Not in aviation we don't, such errors would be... unfortunate . Even a Lufthansa flight at that altitude would report flight level (FL) 410.
fresh_42 said:Sure. I wouldn't have made the mistake if it was 41,000 ft. But it was 12.946 km, which isn't used in aviation. I normally recognize it, but once in a while I slip, seduced by the imagination of a B737 in space.
The main points relevant to this have already been addressed by many other people, but as an airplane buff, I'd just like to point out that the 737 has a max takeoff weight of just under 200,000lb in its largest configuration, and can carry around 175 people 3000-3500 nautical miles or so. The A330 in its largest configuration is well over 500,000lb, with a max seating capacity over 400 people and a range of over 6000 nmi. I wouldn't really consider the two in the same class. Here's a picture showing both for comparison.russ_watters said:Air France 447 was an Airbus A330, a plane in about the same class as the 737.
gmax137 said:That's when she started screaming.
We got diverted to another airport due to "a problem at our destination airport". When we landed they told us that the problem with the original airport was that its runway was too short for our aircraft to land if its flaps won't deploy... I'd noticed surges of acceleration as we circled over the original airport, presumably as they throttled up to counteract the expected drag from the flaps.Vanadium 50 said:A 777 is big, but it can move when it has to.
There was once an Indian B-747 who touched down too early and crashed the entire signal system.Vanadium 50 said:Never lost an engine on takeoff, but had an aborted landing once. Coming into FRA and I am looking out the window and thinking "Hmmm...I've never seen the Waldstadion look so clear" and then we wooshed up. A 777 is big, but it can move when it has to.
What a luxury. I once landed in a Russian town 300 km away from the destination. They said something about the weather, but it was a clear day. They said that we will possibly fly the remaining rest in an hour or so. The plane was full of red cross personal and other NGO stuff headed to watch what the Russians would do in Chechnya. They must have heard me talking as I had been asked in German whether I was an observer, too. No, I said, I'm here for drinking. The point is, after an hour we saw that they had packed the baggage somewhere without noticing anyone. I was accompanied by a local so we grabbed our suitcases and booked a bus tour. I have no idea what had happened to all the others, presumably not speaking Russian. The bus was funny, too. We stopped somewhere in the middle of nowhere so that people could go for the toilet, which was into the bushes, and coming back to the bus, I saw that its lights were so dim, that I wondered whether we could be seen at all in the (meanwhile) dark. Plus I could read the advertisement on the side of the bus. It was in German. And it was not new.Ibix said:The whole thing added about fifteen minutes to our flight, plus about an hour and a half on a bus to our original airport. That's when I developed a gut feel for how fast planes actually travel.
Vanadium 50 said:A 777 is big, but it can move when it has to.
russ_watters said:The scenario isn't just odd, it is poorly defined and not physically realistic. Just having engines fail doesn't cause an airplane to fall in freefall, and the descent rate depends entirely on the orientation. E.G., is it gliding, diving or stalled?And on the other side of the coin is Air France 447, which stalled, fell out of the sky and crashed with little forward speed and the engines at full throttle.
Air France 447 was an Airbus A330, a plane in about the same class as the 737. It fell in a powered stall from 38,000 feet (11.6 km) in about 4 minutes. That's an average vertical speed of 108 mph or about the terminal velocity of a skydiver.
To calculate the terminal velocity we need to know the drag force from air resistance as a function of speed. Terminal velocity is that speed at which the drag force exactly counteracts the weight.shotokan said:Isn’t there a formula for terminal velocity gravity x acceleration x weight or something like that?
Possibly, but the plane in that crash did not stay in the vertical dive all the way from altitude. It dove fairly far down, leveled off, and then did the final fatal dive.Arjan82 said:Perhaps the question is related to this crash?:
https://www.bbc.com/news/business-61488976
Terminal velocity is the maximum speed that an object can reach while falling through a fluid, such as air or water. It occurs when the force of gravity pulling the object down is equal to the force of air resistance pushing against it.
The formula for calculating terminal velocity is Vt = √(2mg/ρAC), where Vt is the terminal velocity, m is the mass of the object, g is the acceleration due to gravity, ρ is the density of the fluid, A is the cross-sectional area of the object, and C is the drag coefficient.
The terminal velocity of an object is affected by its mass, surface area, and the density and viscosity of the fluid it is falling through. Objects with a larger surface area and lower density will have a lower terminal velocity, while objects with a smaller surface area and higher density will have a higher terminal velocity.
The altitude does not significantly affect the terminal velocity of an object in free fall, as long as the object is still within the Earth's atmosphere. However, at higher altitudes where the air is less dense, the object may experience a slightly higher terminal velocity due to decreased air resistance.
The terminal velocity of a Boeing 737 in free fall from 12.496km would depend on various factors such as the weight and size of the specific aircraft, as well as the air density and other environmental conditions. It is not possible to accurately determine the terminal velocity without more specific information.