B747 door opens in mid-air

[iSamurai]

http://news.monstersandcritics.com/...obes_mid-air_opening_of_Boeing_747_cabin_door

I'm in Taipei at the moment and this was on TV this morning. How can it not been noticed? Luckily it was noticed at 1000ft, but they dumped fuel (omg, I'm no environmentalist but seriously...) and then returned to Taipei (it was bound for LA I think). China Airlines really has a patchy safety record... Their plane exploded a few months ago (B737) in Okinawa, no1 was injured.

 

[nbs2]

I'm in Taipei at the moment and this was on TV this morning. How can it not been noticed? Luckily it was noticed at 1000ft, but they dumped fuel (omg, I'm no environmentalist but seriously...) and then returned to Taipei (it was bound for LA I think). China Airlines really has a patchy safety record... Their plane exploded a few months ago (B737) in Okinawa, no1 was injured.

I hadn't heard about this, and other than your link haven't seen anything (not that I've ventured outside my usual news feeds), but wow.

As for the dumped fuel, someone may be able to shed more light, but in my conversations with airline pilots they have all confirmed that landing a plane is a pretty exact science, and those calculations are based on having a narrow range of fuel. It is one of the reasons (among many, including a backup up airport) that planes will have to circle before landing - they have too much fuel and need to burn it. However, this is pretty rare, as fuel is fuel and it's cheaper not to need to burn it, don't worry that this is happening on a regular basis. Here, dumping quickly evaporated fuel is better than risking the lives of all the passengers in either an unsafe landing or remaining in the air with a faulty door.

 

[Caezar]

China Airlines should be shut down, pure and simple. It has the second worst safety record in the world after Cubana.

9 or 10 hull losses in the past 30 or 40 years. That cannot be explained by "bad luck".

I never fly China Airlines. I fly Cathay whenever possible, or EVA Air. I had rather cross the Taiwan Straights on a raft.

 

[John Jacob]

China Airlines should be shut down, pure and simple. It has the second worst safety record in the world after Cubana.

Hey, aren't you forgetting Aeroflot? That was the airline where, a few months ago, the flight crew got drunk and when one of the passengers protested, roughed him up.

I've flown on a couple of China airlines flights once before (it was a Shenzhen <--> Beijing round trip). I'm just not sure whether it was China Airlines or South China Airlines. Anyway, nothing untoward happened on either of those flights, although I realise that says nothing about the airlines safety record.

 

[JNB]

As far as the dumping of fuel, two reasons. First, max landing weight requires (and assumes) that a great deal of the fuel is burned off in flight, so on a sudden return like that, it's lose either fuel, cargo, or pax. Fuel's easier. Also, less fuel in the plane = less fuel to be spread on the ground should a breach occur during landing.

The door issue is less of a "omigawd!" than a "oh, poo." Main cabin doors should all be hinged or articulated to open to the front of the fuselage. Aerodynamic forces in flight would keep them essentially closed, but not sealed. Aircraft doors exploding out and sucking dozens of passengers and seats out is purely Hollywood.

 

[Stampyhead]

Hey, aren't you forgetting Aeroflot? That was the airline where, a few months ago, the flight crew got drunk and when one of the passengers protested, roughed him up.

Ha ha, I'd never heard about that. That's freakin' funny. I mean, it isn't, but it is...

 

[iSamurai]

I've flown on a couple of China airlines flights once before (it was a Shenzhen <--> Beijing round trip). I'm just not sure whether it was China Airlines or South China Airlines.

China Airlines is not China Southern. China Airlines is operated in Taiwan.

Here, dumping quickly evaporated fuel is better than risking the lives of all the passengers in either an unsafe landing or remaining in the air with a faulty door.

Oh I see, well fuel evapouration in mid air, I think, really depends at day or night, and in this case, it's at 1000ft altitude. I can understand why they do this, is because they must achieve the maximum landing weight, and since they are flying across the Pacific they carried a lot of fuel.

The door issue is less of a "omigawd!" than a "oh, poo." Main cabin doors should all be hinged or articulated to open to the front of the fuselage. Aerodynamic forces in flight would keep them essentially closed, but not sealed. Aircraft doors exploding out and sucking dozens of passengers and seats out is purely Hollywood.

People getting sucked out is, obviously, Hollywood. But at an operating altitude of let's say, 12000ft, the atmospheric temperature is -52 degrees celcius, and there's no oxygen.

According to the news on TV there's people crying and all that they're pretty scared.

 

[JNB]

People getting sucked out is, obviously, Hollywood. But at an operating altitude of let's say, 12000ft, the atmospheric temperature is -52 degrees celcius, and there's no oxygen.

I think you're mixing some calculations. At 12,000 ft, standard temperature would be +16.2 F/-8.8 C. At 12,000 m, it's -56.5 C/-69.5 F.

As far as oxygen, yes, there is at both altitudes, although at 12,000 meters, there is insufficient pressure to sustain life for long. At sea level, O2 pressure is about 3 lbs/ft2. At 36,000 feet, it's about 0.69 lbs/ft2. Just no way for us to exchange the available oxygen at that low of a pressure.

On a side note, our O2 requirement drops substantially with gains in elevation, and although the volume of oxygen we need is there, we just can't draw it out. The average person breathes in some 11,000 liters of air per day, with the inhaled air having approximately 21% O2 and the exhaled air 15% O2. This equates to an average consumption and use of 350 to 550 liters of oxygen per day at maximum oxygen uptake. As you gain altitude this maximum oxygen uptake(VO2max) decreases by 10% for every 1000m gained above 1200m. 12,000 meters gets us to a VO2max of about 17 ml/kg/min, still above the 7 required for survival, but supplemental oxygen under pressure is still required for anything approximating normal, safe functioning.

 

[tjw7676]

Just as a side note regarding O2 and functioning capability. It is possible to fly a plane and function at 12,000ft without pressurization and O2, but you will only be able to function for 2 to 3 hours max before hypoxia sets in. For those of you who don't know, hypoxia is when the body becomes deprived of oxygen. After that 2 to 3 hour time period, which can be less if you are out of shape, you may become incapacitated and lose consciousness. Of course, if you have oxygen then this time can be upped. If you are at 25,000ft then the time of useful consciousness is only 3-5 minutes.

 

[koobcamuk]

This is seriously worrying.

 

[GoCubsGo]

Someone is gonna get fired. I'd start with the moron who dumped the fuel mid-air.

 

[JNB]

Someone is gonna get fired. I'd start with the moron who dumped the fuel mid-air.

Gonna be a lot of morons, then. That's accepted practice for the airframes that have the capability, though most today don't. Even on normal approaches, quite a few will vent off excess to lighten up for landing if they had favorable enroute winds and didn't burn off sufficiently prior to landing.

http://en.wikipedia.org/wiki/Fuel_dump_systems

 

[phillipjfry]

I think you're mixing some calculations. At 12,000 ft, standard temperature would be +16.2 F/-8.8 C. At 12,000 m, it's -56.5 C/-69.5 F.

As far as oxygen, yes, there is at both altitudes, although at 12,000 meters, there is insufficient pressure to sustain life for long. At sea level, O2 pressure is about 3 lbs/ft2. At 36,000 feet, it's about 0.69 lbs/ft2. Just no way for us to exchange the available oxygen at that low of a pressure.

On a side note, our O2 requirement drops substantially with gains in elevation, and although the volume of oxygen we need is there, we just can't draw it out. The average person breathes in some 11,000 liters of air per day, with the inhaled air having approximately 21% O2 and the exhaled air 15% O2. This equates to an average consumption and use of 350 to 550 liters of oxygen per day at maximum oxygen uptake. As you gain altitude this maximum oxygen uptake(VO2max) decreases by 10% for every 1000m gained above 1200m. 12,000 meters gets us to a VO2max of about 17 ml/kg/min, still above the 7 required for survival, but supplemental oxygen under pressure is still required for anything approximating normal, safe functioning.

I'm really sorry, but I have to ask, what the hell do you do for a living???
That is probably the most interesting thing I've read all da....week!

 

[JNB]

I'm really sorry, but I have to ask, what the hell do you do for a living???
That is probably the most interesting thing I've read all da....week!

These days, travel the country training. I'm just an inveterate fact freak...

 

[jbernie]

The door issue is less of a "omigawd!" than a "oh, poo." Main cabin doors should all be hinged or articulated to open to the front of the fuselage. Aerodynamic forces in flight would keep them essentially closed, but not sealed. Aircraft doors exploding out and sucking dozens of passengers and seats out is purely Hollywood.

Unfortunately the same cant be said for the cargo doors and that trans pacific United flight a few years ago.

Dumped fuel evaporates so for the most part there is little to no environmental affect.

 

[IJ Reilly]

The most eye-popping aspect of this story is that it apparently only came to light because a passenger tattled on the airline. I hope I read that wrong.

 

[theBB]

The door issue is less of a "omigawd!" than a "oh, poo."

I know of at least one passenger plane whose cargo door has malfunctioned in mid-air. The sudden change in pressure caused the plane to crash killing everybody on board.

 

[JNB]

I know of at least one passenger plane whose cargo door has malfunctioned in mid-air. The sudden change in pressure caused the plane to crash killing everybody on board.

There's been a few. The key difference here is this wasn't a cargo door, but a cabin door. Totally different mechanisms. Also, those are less an issue of pressure change than flight dynamics are suddenly and drastically altered. If a cargo door became completely separated, it could damage control surfaces, making the aircraft uncontrollable.

 

[Rodimus Prime]

Someone is gonna get fired. I'd start with the moron who dumped the fuel mid-air.

no dumping fuel was the right move to do. First off the plane was 2 heavy to land. 2nd when plans make an emergency landing they do not want a lot of fuel incase there is a fire or a tank ruptures.

It is standard practice for emergency landings. Max take off weight is a lot higher than max landing weight.

 

[KonaGecko]

Can't function above 12,000 ft.?

It is possible to fly a plane and function at 12,000ft without pressurization and O2, but you will only be able to function for 2 to 3 hours max before hypoxia sets in. After that 2 to 3 hour time period you may become incapacitated and lose consciousness.

I know the flight guidelines recommend PILOTS have supplemental oxygen above 8,000 ft. for safety, however the entire capital of Bolivia, La Paz, is at 13,000 ft and most folks seem to manage not to lose consciousness, although the visiting soccer team is at a distinct disadvantage when playing Bolivia at home!

 

[RedTomato]

Something's wrong here.

Cabin doors open inwards (then they rotate slightly before opening outwards) so they are always plugged shut by the high pressure in the cabin (as compared to the low pressure outside).

http://www.everything2.com/index.pl?node_id=1783222

Thus it should be physically impossible to open a cabin door in mid-flight.

 

[Buran]

People getting sucked out is, obviously, Hollywood.

Depends on exactly what happened. There was a famous incident in which passengers did get sucked out -- an Aloha Airlines jet lost the top of its cabin roof due to fatigue cracks and at least one individual (a flight attendant, I think) who wasn't belted in was sucked out. There was another case -- I forget the airline -- in which part of the cabin wall blew out and in that case as well a few rows of seats were sucked out.

Air travel is still far safer than car travel, however, so this isn't an excuse to panic.

As for wanting to fire whoever dumped the fuel -- they'd have been wrong if they had not done it. The reason why has already been explained by others. There is a time and place for environmental worries and this is not it. (and this coming from someone who really cares about the environment).

 

[.JahJahwarrior.]

The linked article says they dropped 6.3 tons of fuel. That's 6.3*2000#=12,600# of fuel. According to one website, Jet A fuel is about 6.84 pounds per gallon. 12,600/6.84=1,842 gallons of fuel dumped. That seems like a lot, but according to this website, the fuel capacity of a 747-400 is 57,285 gallons. This means they dropped 1/31th of their fuel.

Did I do any of that math wrong? That seems like an awfully large amount of fuel for one plane to carry....and pretty heavy, too! Fully loaded, that should be 195 TONS of fuel.

It's late, I'm sure I'm making a mistake or missassumption somewhere. Can someone please point out where? If I'm wrong, and I remember to come back and read this later, I'll correct this post. Thanks!

 

[xsedrinam]

I think we'll stick with AA to Beijing next summer.

 

[JNB]

The linked article says they dropped 6.3 tons of fuel. That's 6.3*2000#=12,600# of fuel. According to one website, Jet A fuel is about 6.84 pounds per gallon. 12,600/6.84=1,842 gallons of fuel dumped. That seems like a lot, but according to this website, the fuel capacity of a 747-400 is 57,285 gallons. This means they dropped 1/31th of their fuel.

Did I do any of that math wrong? That seems like an awfully large amount of fuel for one plane to carry....and pretty heavy, too! Fully loaded, that should be 195 TONS of fuel.

It's late, I'm sure I'm making a mistake or missassumption somewhere. Can someone please point out where? If I'm wrong, and I remember to come back and read this later, I'll correct this post. Thanks!

Nope, all looks to be right on all counts. Folks are kinda shocked when they encounter and really think about the volumes, weights, thrust, etc., of large modern aircraft.

Keep in mind, they may or my not have had a full load, and only had to vent off enough to bring the aircraft below max landing weight.