Plane Loses Pressure In-flight

[700UW]

Posted on Fri, Jun. 17, 2005
Plane loses pressure in-flight

Flight 1127 lands safely in Charlotte

MELISSA MANWARE AND TONY MECIA

A US Airways plane lost pressure in-flight Friday night making some passengers sick and sending paramedics, firefighters and police rushing to Charlotte/Douglas International Airport.

The airplane landed safely just before 10 p.m., a U.S. Airways spokeswoman said.

Charlotte Obserever (free subscription)

 

[USFlyer]

So this explains all the emergency vehicles when we landed tonight ...

 

[robbedagain]

what causes a plane to lose pressure?

 

[flyin2low]

what causes a plane to lose pressure?

Problems with bleed valves, packs or outflow valves, pressure controllers......


But, how do you get sick from a loss of pressure???

 

[USAirBoyA330]

Hypoxia...yikes. Depending on how Rapid the pressure loss people can black out and pop blood vessels. It's makes you have an intense sick/dizzy feeling followed by euphoria at times.

 

[hp_fa]

Don't forget ear and sinus problems if the plane depressurizes fairly fast. However, hypoxia is by far the biggest threat. In a rapid decompression you only have seconds to get on oxygen. In a slow decompression the effects occur gradually and sneak up on you.

 

[Schwanker]

Decompression sickness can be similar to the "Bends" from SCUBA diving. It is basically caused by the nitrogen in the blood. This is why people "prebreath" O2 prior to diving - or using altitude chambers. See below:

The Bends - Decompression Syndromes


The Bends Symptoms

Well over half of divers with decompression illness report symptoms within 1 hour of surfacing from the dive. Some 95% of victims show symptoms within 6 hours. Almost all show symptoms within 24-48 hours. The nitrogen bubbles released during surfacing cause damage by mechanically obstructing blood flow. Additionally, they cause a local chemical disruption of the vascular beds.

Specific symptoms include these:

The bends: The bends are joint pains involving the arms or legs. Intensity varies from mild to severe. Arms are more commonly involved than legs. The pain is usually most prominent around joints and is sometimes relieved by direct pressure. This occurs because nitrogen is released into the joints and muscles.
Itching: Skin itching usually goes away by itself but may progress to include other symptoms of decompression illness.


Skin: Rashes can be red or marbled. They can be accompanied by itching.


Lymph nodes: They can be swollen and painful.
Pain: Pain can occur at the head, neck, or torso. Pain at these sites versus the arms or legs carries a worse prognosis.
Nervous system: Someone with decompression illness often has nervous system complaints, such as weakness on one side of the body, numbness, pains shooting down an arm or leg, inability to urinate or defecate, or other strokelike symptoms. This occurs because nitrogen bubbles released into the circulation obstruct blood flow in areas of the brain or spinal cord.
Chokes: Decompression illness rarely causes breathing systems problems called the "chokes." Symptoms include burning chest pain, cough, and shortness of breath.
Staggers: Occasionally someone with decompression illness may have symptoms suggesting an inner ear problem, such as a spinning sensation, deafness, ringing in the ears, or vomiting. This group of symptoms is called the "staggers."

 

[Schwanker]

Here's a good analogy how Nitrogen can impact the body on decompression:


A clear example to illustrate this process is that of a bottle of carbonated soda. A bottle of carbonated soda is filled with gas (carbon dioxide), which cannot be seen because it is dissolved in solution under pressure. When the bottle is opened, the pressure is released and the gas leaves the solution in the form of bubbles. A diver returning to the surface is similar to opening the bottle of soda. As a diver swims to the surface, the pressure due to nitrogen decreases. The nitrogen, which has dissolved in tissues, wants again to leave, because the body can hold only a certain amount based on that nitrogen pressure.

If a diver surfaces too fast, the excess nitrogen will come out rapidly as gas bubbles. Depending on which organs are involved, these bubbles produce the symptoms of decompression sickness. The process is similar to shaking a can of carbonated soda. If the pressure is high enough, the carbon dioxide in the soft drink will emerge upon opening the can as a gush of bubbles.


The risk of decompression illness is directly related to the depth of the dive, the amount of time under pressure, and the rate of ascent. Dive tables, such as the US Navy Dive Tables, provide general guidelines as to what depths and dive times are less risky for the development of decompression sickness. Much of this data was gleaned from actual human divers in experimental diving units.

I know this article is related to diving, but the physiological effects of a rapid decompression is the same. The variants are the rated of decompression, the change in cabin altitude (ie...cabin pressure went from 4K to 15K--or whatever actually happened) that actually took place.

 

[luvthe9]

If you can get a tail number we can call maintance and find out what the cause was.

 

[nycbusdriver]

I don't think the pressure change from an airplane rapid depressurization can cause depressurization sickness ("the bends.) The pressure differential is only about 6-8 psi. This is far less than the differentials experienced in scuba diving.

Additionally, the time spent at the decreased pressure is a matter of seconds, since the pilots must bring the aircraft down to 10,000 feet immediately to avoid hypoxia in the passengers and cabin crew. This "high dive" maneuver is one that is practiced before a pilot is licensed to fly a particular model (type-rated.)

Finally, I suspect that, if "the bends" were a consideration during a rapid depressurization, at some time in my USAF and/or airline career it would have been mentioned in ground school or during my altitude-chamber training. It wasn't.



On another note, does anybody know the aircraft type involved. I don't care to get my "free" subscription to the Charlotte Observer.

 

[ClueByFour]

The article and FLIFO indicate a 737-300.

 

[Schwanker]

Finally, I suspect that, if "the bends" were a consideration during a rapid depressurization, at some time in my USAF and/or airline career it would have been mentioned in ground school or during my altitude-chamber training. It wasn't.

[post="277704"][/post]​

The BENDS is trained at every USAF chamber ride. It use to be a 3 year requirement and now is a 5 year requirement for AF aircrew. They also have dive chambers at some AF bases and have had to utilize them for this exact reason. EX...Beale AFB has an altitude chamber and has sent people to Travis AFB's dive chamber for -- the "BENDS." This is fact.

During chamber rides, you breathe 100% O2 for 30 minutes to rid the body (or lower the concentration) of nitrogen. The reason: To reduce the occurence of decompression sickness to include the BENDS. This is very clearly explained during the altitude chamber training. This is also fact.

I totally understand the pressure D is significantly less for a rapid D then actual deep diving, although I've had a good friend DNIFed after an altitude chamber ride due to the BENDS. He also had to spend time in a dive chamber to help with the recovery. Again, this is fact.

Not sure the last time you went through the AF Altitude Chamber training. I've been through it periodically since 1988 and clearly been briefed on the BENDS at every ride. Also, I know the flight doc who is in charge of the dive chamber at Travis AFB. He's shared some stories about people whom he's treated from altitude chamber rides from their AF altitude training.

 

[LGA / 037]

Maybe its more like the Rabinowitz Rabinowitz & Rabinowitz or 1-800-LAWYER factor ! A few of these dopes think they can sue if there is such a tramatic episode as an emergency landing ! Guess they will have to take a back seat behind the SECURED CREDITORS since UAIR is still in Chap 11 !

 

[nycbusdriver]

The BENDS is trained at every USAF chamber ride. It use to be a 3 year requirement and now is a 5 year requirement for AF aircrew. They also have dive chambers at some AF bases and have had to utilize them for this exact reason. EX...Beale AFB has an altitude chamber and has sent people to Travis AFB's dive chamber for -- the "BENDS." This is fact.

During chamber rides, you breathe 100% O2 for 30 minutes to rid the body (or lower the concentration) of nitrogen. The reason: To reduce the occurence of decompression sickness to include the BENDS. This is very clearly explained during the altitude chamber training. This is also fact.

I totally understand the pressure D is significantly less for a rapid D then actual deep diving, although I've had a good friend DNIFed after an altitude chamber ride due to the BENDS. He also had to spend time in a dive chamber to help with the recovery. Again, this is fact.

Not sure the last time you went through the AF Altitude Chamber training. I've been through it periodically since 1988 and clearly been briefed on the BENDS at every ride. Also, I know the flight doc who is in charge of the dive chamber at Travis AFB. He's shared some stories about people whom he's treated from altitude chamber rides from their AF altitude training.

[post="277713"][/post]​

OK. You're right that the bends is discussed, but only in relation to not flying withing XX number of hours after diving. They never said an aircraft rapid depressurization could result in the bends. Before I posted, I researched many website and none talked about the bends resulting from a depressurization of an aircraft. There's just not enough time to develop symptoms before the aircraft is back at a reasonable altitude, so therefore it's not a consideration.

 

[CLTTPA]

Amongst all the excitment, it still landed 9 minutes early!!!