I fly the 172 a lot in FS and was just wondering, at what altitude MUST supplemental Oxygen be used? I'm reading about a lot of pilots that fly 172's on trips at 11000 or 12000 feet and one mentioned using O2 at 14000. I thought the magic number was 10000. Thanks. Tom

I beleive it should be 10000. You can go higher obviously, but hypoxia is not a good thing to suffer from. Passenger oxygen or the "rubber juggle" is used for altitudes above 14000. These are just general rules, there are other rules depending on aircraft size/capacity, type of operation etc

In the U.S., 12500' is the number where supplemental oxygen is required for the pilot. Since I live at an altitude of 4600' to start with, I've adjusted and don't think twice about flying at 10,500 and 11,500 without supplemental oxygen. A short period at 12499.9 isn't going to make my brain fall apart either. :D Now, if I happened to be a sea-level smoker, then everything could be drastically changed. I might need full oxygen just to stay alive! :-hah With mountain ranges out here varying from 9,000 to 13,528, it's very common to be flying between 9500 & 11500 msl. in a small plane. Of course on bad days, a 172 & Piper Archer might stuggle to get to 11,500'.L.Adamson

Here's the actual rule Part 91.211Up to 12,500' = No supplemental oxygen required.12,500 - 14,000' = Minimum flight crew must use Oxygen after 30 minutes of flight time.14,000-15,000' = Minimum flight crew must use Oxygen for the entire flight time.15,000' and above = ALL occupants must be supplied with supplemental oxygen.*Note. Oxygen recommended above 8,000' MSL at night.Hope this helps guys. ** Edit: I thought I was always told to never give high flow oxygen to a smoker, could be wrong here.

<>As noted in another post, the 02 requirement does not begin until 30 minutes after passing 12,500 ft...and the requirement extends beyond the pilot to include whatever the minimum crew might be. In most commercial ops or any aircraft not certificated for single pilot ops, the rule would include the co-pilot.Regards,Jim

>** Edit: I thought I was always told to never give high flow>oxygen to a smoker, could be wrong here.I believe you are correct. I'm a marine engineer officer with the Royal Fleet Auxiliary. From time to time we have to enter "dangrous spaces" that may have recently contained toxic or flammable atmospheres. I've been trained in rescuing casualties from such spaces. The standard procedure is to use a ventilator on the casualty which delivers pure oxygen. I was told never to use this pure oxygen on a casualty with a respiratory disorder as it can kill them.

In Canada you have to use it after 30 mins over 10,000 feet, and anytime above 13,000 feet.However, it really varies from person to person when you need to use it. Heavy smokers or people with respiratory illness may need it even at much lower altitudes. The important thing for pilots is to have proper training in recognizing the symptoms of hypoxia and to learn when they themselves need supplemental oxygen.

>Now, if I happened to be a sea-level smoker, then everything>could be drastically changed. I might need full oxygen just to>stay alive! :-hah >What about a sea level non smoker like me?

t

Expanding on Part 135 operations, flight crew is required to use O2 when cruising between 10,000 and 12,000 for 30 minutes or more. Above 12,000, crew must be using O2 at all times.

>>*Note. Oxygen recommended above 8,000' MSL at night.>What difference does night time make?Rhett

RhettThe night time bit is because the first thing to go with altitude is your night vision.Infact 8000 is high as night vision starts to go off at 5000 feet.There are some pilots who will breath oxygen before landing at night.I have done a lot of high altitude flying in unpressurised twins and often use FL120 one way and FL130 the other always checking what the actual altitude is against 29.92 or 1013.Any higher and its oxygen.The Seneca fives with their turbocharged intercooled engines love to fly high with a service ceiling of 25000 feet and fantastic climb rate to get high.I often fly at FL190 or FL200 and the highest I have taken a Seneca five was FL230Peterhttp://forums.avsim.net/user_files/149755.jpg

Wow, thank you for the information Peter.The highest I have been (walking, not flying) is about 12,500 feet ASL, on a mountain...and it was hard work climbing at that altitude. Can't imagine being at 23,000, even sitting still...I'm sure the air feels thin. To me, the air feels "thin" at 8-10 thousand feet vs. 5,000.Rhett

>Rhett>>I have done a lot of high altitude flying in unpressurised>twins and often use FL120 one way and FL130 the other always>checking what the actual altitude is against 29.92 or 1013.>>Any higher and its oxygen.>Are you talking about real flying now? Also are the pic from real world? Does unpressurized twins have oxygen masks as a standard?I was wondering about the Baron B58 that can cruise far above 12500.So that is not unrealistic in spite of being unpressurized, since there is oxygen masks.

Generally speaking, unpressurized piston twins or even singles do NOT have built in O2 masks as standard equipment, however they can sometimes (depending upon model) be an installed option upon manufacture, can be installed later, and besides, that is all irrelevant anyhow.Why? Because you can always use a "portable" oxygen system, one that can be used in any aircraft. Some searching on Google will advise you of the systems that are available.My Piper Dakota can get up to 17,500' (not easily, but it can). It does not have a built-in oxygen system, but I can always use a portable one.Do I own a portable O2 system? No. Thus I do not fly the plane at altitudes that require O2.The Baron 58 aside, most aircraft can get to altitudes that require oxygen, but that does not mean the aircraft is required to have a built-in oxygen system.Some aircraft, especially turbocharged ones do have built-in systems, as these turbo charged aircraft can easily get into the flight levels, but some do not. The current model Baron 58 does not have a built-in oxygen system. It is also not turbo charged. My friend has Columbia 400, it is turbo charged, can easily get into the flight levels, and does have a built-in O2 system.The Seneca V is also turbo charged, and I believe that a built-in O2 system is standard equipment (can't check for sure as the Piper web site is having porblems).Again, it is all irrelevant as a portable system can always be used.Learn more here: http://www.aerox.com/Or here: http://www.mhoxygen.com/Or here: http://www.nelsonoxygen.com/Regards,http://www.dreamfleet2000.com/gfx/images/F...R_FORUM_LOU.jpg