Question for real pilots?

[John_Cillis 2,406]

Recently I downloaded the Carenado 210T Centurion. A fast aircraft if you climb into the flight levels. My question to real pilots: If you're on a flight that requires oxygen, especially at FL200 and above, are there any physical issues that one experiences due to the low air pressure? Or do things feel normal, albeit with an oxygen mask? Just curious, hope to hear some feedback.

 

Regards,

 

John

[KevinAu 441]

The oxygen might make you cough.

[tttocs 301]

The oxygen might make you cough.

 

Funny, but true. Things do tend to get a bit dry. My O2 experience is limited to the mid-teens, not up above FL200 (other than during an altitude chamber ride - highly recommended if you're serious about flying in 02 territory) , but basically that's it.

 

Scott

[vololiberista 205]

It depends on what cabin altitude the oxygen comes on and whether the humidifiers were on at the time or not.There are many factors that affect your reaction to breathing 100% oxygen. Are you a smoker? Have you got a cold coming on? Frequently people feel very disorientated and even nauseous for about a minute or so after donning their mask.

What you must do is don your mask immediately the cabin altitude warning sounds. If you don't you may (depending on the actual cabin altitude) begin to feel the effects of hypoxia. Of which one common reaction is that everything is ok (until you pass out that is!!!!)

[JohnFromCO 15]

Recently I downloaded the Carenado 210T Centurion. A fast aircraft if you climb into the flight levels. My question to real pilots: If you're on a flight that requires oxygen, especially at FL200 and above, are there any physical issues that one experiences due to the low air pressure? Or do things feel normal, albeit with an oxygen mask? Just curious, hope to hear some feedback.

 

I routinely take a T210 from Western CO to SLC and Denver Metro Area. All IFR flights are in the low FL's.

 

Normally there are no physical issues when using cannulas or masks besides dry nostrils. However, it really depends on physical conditioning of the pax and their social activities. Pax who are older or have a history of smoking/drinking just need a higher O2 flow setting. It is just a quick adjustment and most pax just adjust their own flow to their own needs. Hypoxia is easily preventable.

 

The main physical issue pax get when flying in unpressurized aircraft is from the gases inside the human body. Higher pressure gases inside the body like to expand and attempt to exit to lower pressure. It is normal but sometimes embarrassing. That is another good thing about getting O2 from cannuals and telling pax no spicy foods before flight.

[Cessnaflyer 56]

John,

 

Unless one knows what they are doing from more than just an aviation perspective, increasing oxygen levels in anyone during a flight is definitely not suggested. Pilots, often times get this issue wrong and they confuse Hypoxia with Hypoxemia on the one hand, and they rarely (if at all) ever get around to understanding the potential effects that too much oxygen can have on the human body, also called Hyperoxia. I've always been of the opinion the GA Pilots (especiall) need to take the time to educate themselves on both sides of the O2 chemical equation.

 

You should be aware of the fact that too little oxygen can lead to Hypoxia through the common gateway of initial Hypoxemia (the two are not the same). However, too much oxygen in your system can be causal for Hyperoxia, which in return can be causal for reduced peripheral blood circulation throughout your body, but initially on the left side of your body. Either of these conditions can be unsafe for both the GA pilot and their passengers.

 

Hypoxemia, is related to what's called the "low partial pressure of O2." This is essentially a low ratio between your blood and O2 levels within circulatory system. It is important to know that Hypoxemia, can have several other causations unrelated to lower ambient air pressure as well, and if the pilot and/or passengers are subject to these other biological factors that cause them to be candidates for non-pressure related Hypoxemia, the effects of flying in unpressurized cockpits and cabins at altitudes that are below the FAA maximum for the use of ABO, can add some additional negative side-effects.

 

So, before you fly any GA aircraft above what would be considered "normal" cabin pressurization levels on a commercial flight (typically in the 7,500 to 8,500 cabin altitude range), you should query your passengers about any known medical issues they might have that makes them more susceptible to Hypoxemia related symptoms (do your research on how those symptoms manifest themselves), as that will typically occur before full blown Hypoxia instantiates. An ounce of prevention is worth a pound of cure in this regard.

 

On the flipside of the equation is the matter of Hyperoxia. Taking "extra oxygen" by increasing the ratio being delivered through an ABO system merely because it sounds cool, or because you think its ok, might not prove to be the best, or wisest move you can make as a pilot, or as a passenger. Remember, oxygen naturally lowers circulation, but it also can reduce the natural stimulus for auto-pulmonary reaction. That means, that too much oxygen in your system can lower your respiratory rate unnecessarily. As a pilot, you don't want to suppress your breathing at any time, let alone when flying. Nor, do you wish to cause other health problems for your passengers, merely because you gave them bad advice out of ignorance.

 

Part 91 governs the use of ABO and it covers both pressurized and non-pressurized cabin types, ranging from 12,500ft/msl, all the way through FL350, with differences in when and how ABO is to be used up the altitude and time ladder. Part 121, covers commercial operations and its required use of ABO.

 

When in doubt, study the FARs for specifics on usage and how to remain both legal and safe as a GA pilot. And, by all means, never increase and/or decrease your ABO ratios without having a very good understanding about what you are doing, why you are doing it and how to do it correctly, so that you do not run into problems with SOF as PIC.

 

In other words, educate yourself about the natural effects of too much, or too little ABO at altitude.

 

Hypoxemia is Hypoxic Hypoxica which is the form that is caused 99.9% of UCs in aviation. It is the lack of partial pressure to the alveoli which is caused by the lack of partial pressure from the altitude. The only way to combat this is to add extra oxygen to the air solution. The only other way to do it is to pressurize the lungs which leads to huge difficulties in light general aviation aircraft.

[vololiberista 205]

Hypoxemia is Hypoxic Hypoxica which is the form that is caused 99.9% of UCs in aviation. It is the lack of partial pressure to the alveoli which is caused by the lack of partial pressure from the altitude. The only way to combat this is to add extra oxygen to the air solution. The only other way to do it is to pressurize the lungs which leads to huge difficulties in light general aviation aircraft.

 

That is why aircrew must be on 100% oxygen. Typically an a/c fitted with oxygen under pressure (contrary to those fitted with chemical cannisters) will have a storage supply of 1,850psi theough a reduction valve to 350psi delivering emergency oxygen at 80psi and therapeutic oxygen at 40psi. with enough oxygen to last at least 4 hours or more. Therefore the advantage of a pressurised oxygen system is that it doesn't run out after 15 minutes!!!