Van's Air Force
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High altitude flight
- Thread starter tkatc
- Start date
High Altitude Flight
A few years ago I flew from Origon to Kenosia WI with only one stop. I cruised at 9500' (VFR) for over 9.5 Hrs. When I got to Kenosia, I almost lost control of the plane on landing. My thinking was far behind the plane, and slow to realize where I was in the pattern. After landing and caring for the plane, I laid down on an outside table while waiting for my ride, and instantly fell asleep! Only the horn of my ride's car woke me up...
So I put an O2 bsystem into the plane. With it, I'm able to fly at high altitudes for long periods, and see a very noticable difference in my energy levels and clarity of thinking when I get to my destinations..
If you're not used to the lower O2 levels (I'm from the East coast), don't fly at altitudes for long periods without the additional O2.....
A few years ago I flew from Origon to Kenosia WI with only one stop. I cruised at 9500' (VFR) for over 9.5 Hrs. When I got to Kenosia, I almost lost control of the plane on landing. My thinking was far behind the plane, and slow to realize where I was in the pattern. After landing and caring for the plane, I laid down on an outside table while waiting for my ride, and instantly fell asleep! Only the horn of my ride's car woke me up...
So I put an O2 bsystem into the plane. With it, I'm able to fly at high altitudes for long periods, and see a very noticable difference in my energy levels and clarity of thinking when I get to my destinations..
If you're not used to the lower O2 levels (I'm from the East coast), don't fly at altitudes for long periods without the additional O2.....
I did something stupid today and I'm man enough to admit it. (Or stupid enough, take your pick). There are clearly not enough posts in this section.
I was planning a flight from Florida to New Jersey today. The weather south of my airport was VFR. The weather at my destination was severe clear as well. Only problem was a system covering about 300 miles of ground that I didn't feel comfortable bobbing and weaving from underneath. I thought I would have to cancel but realized there was a chance I could go over the top. (Controversial to some of course). With the threat of worse weather over the next several days my getthereitis started to kick in. I figured I could take a local hop and see if I could get on top.
Usual departure, climbed out and found blue skies through some large broken areas. I was on top by 5000' or so. I climbed to 8500 to take advantage of some stronger tailwinds. So far so good. It was quite beautiful and smooth up there. I came upon some towering clouds and decided I could hop over. Up to 10,500 I went. Looking good. But the clouds kept rising...and me with them. I was lured on by some broken opaque holes where I could see the ground if I needed to escape. Next thing I know I'm flirting with 16,000 to rise above a small area. I was able to dip back down into thicker air but only to have to climb over some towers again. I had only gone this high before to top some remnants of the Rocky Mountains but was able to descend quite quickly after clearing the terrain. I remembered the rules about O2 and hypoxia but couldn't recite them verbatim. They are as follows for anyone needing a refresher:
(a) General. No person may operate a civil aircraft of U.S. registry --
(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration;
(2) At cabin pressure altitudes above 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen during the entire flight time at those altitudes; and
(3) At cabin pressure altitudes above 15,000 feet (MSL) unless each occupant of the aircraft is provided with supplemental oxygen.
Anyway, I was above 15,000 for a substantial amount of time without oxygen. Bad move on my part and I could think of no better place to confess my sins. This mistake was fortunate for me as I returned home to NJ safely but I figure this post would be a good reminder for others to prepare properly so you won't sin in a similar fashion. Please feel free to discuss...
I took my high altitude class at Petterson Air Force Base and had a great time...don't know if it is still free (was at the time), but spent the day learning about the effects of altitude and symptoms to look out for...each one being individual...narrowing vision, confusion, ect.... Each of us were taught that the symptoms will vary by individual. So they stuck us in a chamber and we headed up. I was amazed when some started to pass out at 10k and then some couldn't do a simple puzzle at 14k. My personal symptom was narrowing vision at around 18k. The cool thing was that I could actually experience it, and now know how subtle the affects come on. After the experience, we listened to a recording of some guy at 17k coming into Denver, he had been sitting on his o2 hose...thankfully he made it, but at 17k he was so confused that he didn't know his tail number, mumbling into his mike, and as he descended he became more and more coherent. In the end he never knew he had even had a problem. I live at 11500 and run at 12500, but that day gave me a healthy respect... Each person has a limit, my girl friend has been to 8000meters three times without oxygen...they call it "The Death Zone"
I live at 11500 and run at 12500, but that day gave me a healthy respect... Each person has a limit, my girl friend has been to 8000meters three times without oxygen...they call it "The Death Zone"
One VAF member and RV-8 owner has climbed to the top of Mt. Everest. Was suprised to find he was not on oxygen 100% of the time.
flyboy1963
Well Known Member
can we start a thread on this? 02 use etc.
though I fly strictly VFR I think I would like a small bottle.... just for me, if I knew how to properly use it, to get safely over the mountains and the odd weather/broken cu cloud level encountered enroute.
From what I can see, the fingertip oximeters run from $30 to $300, with little difference in posted accuracy. Most are made in China so we can really only go with pireps and medical advice I suppose.
I think the ones that record your 'sats' for later reference are the most valuable, 'cause we are unlikely to religiously check it during our flights, and they start at $85 or so. As others have noted, tolerance varies so widely between age, fitness, acclimation etc. it's impossible to use the so-called 'guidelines' as they just don't apply accurately to real life.
though I fly strictly VFR I think I would like a small bottle.... just for me, if I knew how to properly use it, to get safely over the mountains and the odd weather/broken cu cloud level encountered enroute.
From what I can see, the fingertip oximeters run from $30 to $300, with little difference in posted accuracy. Most are made in China so we can really only go with pireps and medical advice I suppose.
I think the ones that record your 'sats' for later reference are the most valuable, 'cause we are unlikely to religiously check it during our flights, and they start at $85 or so. As others have noted, tolerance varies so widely between age, fitness, acclimation etc. it's impossible to use the so-called 'guidelines' as they just don't apply accurately to real life.
Another factor to be aware of is recent illness that might cause anaemia.
I once had mononucleosis and about a month after feeling completely fit went flying without a check-up.
After ten minutes at cabin altitude of around 7000' I couldn't add two numbers together. Lucky I was an expendable crew member.
It was another 6 weeks before my blood count was back to normal.
I once had mononucleosis and about a month after feeling completely fit went flying without a check-up.
After ten minutes at cabin altitude of around 7000' I couldn't add two numbers together. Lucky I was an expendable crew member.
It was another 6 weeks before my blood count was back to normal.
PaigeHoffart
Well Known Member
Listen to this
Here's a sobering atc audio clip of a very close call with hypoxia:
http://www.natca.org/ULWSiteResources/natcaweb/Resources/media/ArchieLeague2013Audio/SouthwestZFW.wav
It sounds like a slow depressurization up in the high 20's, although the effects can be experienced in the teens. This guy probably had just a few minutes of useful conciousness. In the high teens it might be closer to 30 minutes, but as others have mentioned, factors such as age, illness, smoking, or carbon monixide in the cockpit can significantly increase your chances of experiencing hypoxia at RV altitudes.
Here's a sobering atc audio clip of a very close call with hypoxia:
http://www.natca.org/ULWSiteResources/natcaweb/Resources/media/ArchieLeague2013Audio/SouthwestZFW.wav
It sounds like a slow depressurization up in the high 20's, although the effects can be experienced in the teens. This guy probably had just a few minutes of useful conciousness. In the high teens it might be closer to 30 minutes, but as others have mentioned, factors such as age, illness, smoking, or carbon monixide in the cockpit can significantly increase your chances of experiencing hypoxia at RV altitudes.
kinger
Well Known Member
Controller Praised For Saving Hypoxic Pilot
LouElla Hollingsworth, a veteran air traffic controller with 29 years? experience, saved the pilot of a Piaggio Avanti when she recognized signs of hypoxia in his radio transmissions on November 16 last year. Thanks to Hollingsworth?s quick thinking as a Fort Worth Center controller in Texas, she convinced the pilot to descend to a lower altitude where the oxygen level was suitable for breathing. Hollingsworth and eight other members of the National Air Traffic Controllers Association (Natca) were awarded Archie League Medals of Safety on March 6 for a variety of aircraft saves across the U.S. The Piaggio?N501PM?was being flown single pilot when Hollingsworth cleared the pilot to climb to FL310 and noticed he did not respond. When she again queried the Avanti, she heard only breathing and a number of slurred sentences on the radio. ?November five zero one Papa Mike if you can hear me you need to probably start [down], descend and maintain flight level two four zero,? Hollingsworth said. Only noise is heard on the recording and then ?oxygen?oxygen? can be heard. ?November One Papa Mike, if you got oxygen try that and descend and maintain flight level one eight zero.? A few moments later, she added, ?November Five Zero One Papa Mike, I see you?re out of 27 [000] now descending, maintain flight level one eight zero and try some oxygen.? Hollingsworth asked again how the pilot was feeling. ?Thanks for the help,? he said. ?For some reason the cabin altitude was showing OK but we had some oxygen issues.?
LouElla Hollingsworth, a veteran air traffic controller with 29 years? experience, saved the pilot of a Piaggio Avanti when she recognized signs of hypoxia in his radio transmissions on November 16 last year. Thanks to Hollingsworth?s quick thinking as a Fort Worth Center controller in Texas, she convinced the pilot to descend to a lower altitude where the oxygen level was suitable for breathing. Hollingsworth and eight other members of the National Air Traffic Controllers Association (Natca) were awarded Archie League Medals of Safety on March 6 for a variety of aircraft saves across the U.S. The Piaggio?N501PM?was being flown single pilot when Hollingsworth cleared the pilot to climb to FL310 and noticed he did not respond. When she again queried the Avanti, she heard only breathing and a number of slurred sentences on the radio. ?November five zero one Papa Mike if you can hear me you need to probably start [down], descend and maintain flight level two four zero,? Hollingsworth said. Only noise is heard on the recording and then ?oxygen?oxygen? can be heard. ?November One Papa Mike, if you got oxygen try that and descend and maintain flight level one eight zero.? A few moments later, she added, ?November Five Zero One Papa Mike, I see you?re out of 27 [000] now descending, maintain flight level one eight zero and try some oxygen.? Hollingsworth asked again how the pilot was feeling. ?Thanks for the help,? he said. ?For some reason the cabin altitude was showing OK but we had some oxygen issues.?
As a result of reading this initial post several weeks ago, I bought an oxymeter, and a Mountain High pulse demand O2 system. I was shocked when I filled the tank the first time. The cost was $15 to fill a 24 cu ft tank.
I flew from Austin to Las Vegas last week, and was amazed at the difference oxygen made. My oxsat level at 10k was 87. With oxygen on, it easily moved up to 93. The difference in my lack of tiredness at destination, and my awareness when in flight was shocking. I had not realized how slow my reaction and processing time was on prior trips w/o O2.
I felt enormously more aware and alert flying into Class B airspace at the end of the trip, which is normally when I am hit with both extreme fatigue, and more complicated instructions and decisions.
I would encourage anyone who flies high to give oxygen a try. I will fly with it from now on.
I flew from Austin to Las Vegas last week, and was amazed at the difference oxygen made. My oxsat level at 10k was 87. With oxygen on, it easily moved up to 93. The difference in my lack of tiredness at destination, and my awareness when in flight was shocking. I had not realized how slow my reaction and processing time was on prior trips w/o O2.
I felt enormously more aware and alert flying into Class B airspace at the end of the trip, which is normally when I am hit with both extreme fatigue, and more complicated instructions and decisions.
I would encourage anyone who flies high to give oxygen a try. I will fly with it from now on.
Louise Hose
Well Known Member
Pulse Oximeter
I would caution anyone buying a fingertip pulse oximeter to get one with a brightness level adjustment feature. The first oximeter I puchased is useless because I can not read it in the bright RV cockpit environment. It worked fine when I opened it up in the house. I have one made by Devon Medical Products (model C202) thats works great.
I would caution anyone buying a fingertip pulse oximeter to get one with a brightness level adjustment feature. The first oximeter I puchased is useless because I can not read it in the bright RV cockpit environment. It worked fine when I opened it up in the house. I have one made by Devon Medical Products (model C202) thats works great.
blueflyer
Well Known Member
Sounded like an unidentifed and uninvolved pilot spoke up and transmitted "Oxygen" across the channel and the very aware controller picked up on it. That unidentified pilot saved someone's life.
David Paule
Well Known Member
The only reason to carry it is to use it to assess how you are doing and whether you are getting enough oxygen. Just having one means that you will check it during flight. You almost can't avoid it. Especially if you keep it on a string around your neck.
Since we buy oxygen by the fill-up, get the largest bottle that is practical for you. By minimizing refills, that saves money in the long term.
I've got a professional Nonin oxymeter. It has an LED display and is sunlight readable. The cost for that brightness is relatively poor battery life. But their customer service is exceptional and the unit has been a durable and much-used bit of equipment since 1999.
Dave
I read all the post here today and I hear alot of people say they use oxygen at or above even 9000msl. The truth is if you are in great shape, don't smoke your safty margin is very high. my airport in wyoming is at 7200msl. I fly quite aften around that 15000 to 16000' with out oxygen. I might be used to it a little more since I live at a higher altitude, but if you are crusing around at 12000' I wouldn't even worry about using oxygen. I think a lot of people worry about it to much that it starts playing with there mind. I always have it though on hand. To fly IFR you have to be at 12500' min. The clouds often times don't look as high as they really are and can suck you into thinking o just a little more; glad you made it back.
Sorry Stamper, but your recommendations are dead wrong and dangerous. Make up a page full of two digit math problems on a yellow pad, go to 12,000 feet and time how long it takes to solve them. If you are faced with a tough decision after spending an hour or two at 12,000 feet, chances are, it will be a poor one....
I have a bottle and a Pulse OX. I hit 90% between 8 and 9K and if I fly up there for 4 hours I have a hangover when I land. I fill my own bottle, so cost is no factor.... I only have one filler bottle and when it gets down to 1000, I take it to work and burn it up on the torch, or if the torch bottle is full, I trade and take the torch bottle to the hangar. Either way, no more than a fill costs, I have no worries about taking a bottle back with a 1000 psi in it. It is way cheaper than paying the lease on an extra bottle to make a cascade system.
What nobody has talked about is what I call the "Magic of True Airspeed."
For every flight level you climb you will gain 2% of your indicated airspeed, up to the altitude that you run out of power. Above that you will lose >1% depending on the aspect ratio of your airplane and how heavily wing loaded you are.
My Rocket indicates roughly 175 kts at 23/23 and I can maintain that to 8000 feet. So that means on a Std day, I go 175 KTAS at sea level, and 203 KTAS at 8000.
Above that power drops off so speed starts to decrease, but while the TAS drops a little, the fuel flow drops dramatically. From 203 KTAS at 8000 I will drop to 198 KTAS at 17,000, but my fuel flow will drop from 12.5 to 9.8 gph. That means for a 2.5% loss in airspeed, I can get a 25% reduction in fuel flow.... HUGE!!!
With that said, the EVO Rocket has a TREMENDOUS Aspect ratio and very light wing loading so it benefits from altitude more than a square wing RV, but the benefits are there for the taking.
Typically on long trips, I try to use the winds aloft and fly at 17,000 eastbound and 8,000 westbound. If I am going to spend a long time above 8K I use O2 to keep my PulseOX in the low 90's and I feel great when I get to my destination....
Tailwinds,
Doug Rozendaal
F1 EVO
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My hangar is at 7200' also. I'm at the low point for my neighborhood. Should I carry oxygen in my car? I have to go to at least 9000' to get out of here in 3 out of 4 directions. I suppose I could dig a tunnel. Stamper is right. You get used to it. Either that, or else all of us living up here are too stupid to solve 2 digit math problems.
Stamper said the average person can do fine at 12,000 feet. The average flatlander at 12,000 feet will struggle to do 2 digit math problems... Even though it is legal, most pilots should not fly for extended periods at 12,000 without O2, and especially if it is an IFR flight that might involve ice or other stressors. Pilot performance in MOST pilots at 12,000 feet will be significantly impaired.
No argument, that people who live at high altitude accommodate, but the rule was written based on flying a Ford tri-motor between most of the city pairs in the lower 48 without O2, not on the sound science that we have today regarding O2 saturation vs cognitive function.
brad walton
Well Known Member
Altitude at home
What some seem to be missing is that you body compensates to an extent when you spend time at higher altitudes. If you live at 7500 feet, you will have more hemoglobin in your system able to carry more oxygen at rarified altitudes. I live at 150 feet above sea level and I can feel the effects of low oxygen if I fly at 10,000 feet where my pulse oximeter indicates 91 to 93%. I believe the recommendation is to use supplemental oxygen at 91% or less blood saturation. Those who live at 7500 feet and are in the same physical condition as me may be able to maintain greater than 91% saturation level well above the 10,000 foot level where symptoms of hypoxia begin for me. I wonder if this gives the Denver Broncos an advantage at home games when playing sea level teams?
What some seem to be missing is that you body compensates to an extent when you spend time at higher altitudes. If you live at 7500 feet, you will have more hemoglobin in your system able to carry more oxygen at rarified altitudes. I live at 150 feet above sea level and I can feel the effects of low oxygen if I fly at 10,000 feet where my pulse oximeter indicates 91 to 93%. I believe the recommendation is to use supplemental oxygen at 91% or less blood saturation. Those who live at 7500 feet and are in the same physical condition as me may be able to maintain greater than 91% saturation level well above the 10,000 foot level where symptoms of hypoxia begin for me. I wonder if this gives the Denver Broncos an advantage at home games when playing sea level teams?
People living at higher elevations do have greater hemoglobin levels than those living at sea level(about 7% higher at Denver elevations), and do have somewhat greater tolerance at high altitudes, but nowhere near the bullet proof physiology suggested by Stamper and others.
The oxygen-hemoglobin disassociation curve(look it up) is S-shaped, and there is very little loss in oxygen carrying capacity until we go above 8,000 ft. That is why airliners are usually pressurised to about 8,000 ft. equivalent pressure. Above 8,000 blood oxygen levels decrease more rapidly, even for those who live high. Being fit does help, but it doesn't make you Superman. My wife and I ran the Pikes Peak marathon 13 times, finishing over 14,000 ft. We did have an advantage over the flatlanders, but on top we were still mumbling idiots.
Oxygen on the sidelines of Bronco games is mostly a psychological benefit. The pool at the AF Academy has the elevation marked on the ends of each lane, to psych out the visiting swimmers.
Jim Berry
RV-10
The oxygen-hemoglobin disassociation curve(look it up) is S-shaped, and there is very little loss in oxygen carrying capacity until we go above 8,000 ft. That is why airliners are usually pressurised to about 8,000 ft. equivalent pressure. Above 8,000 blood oxygen levels decrease more rapidly, even for those who live high. Being fit does help, but it doesn't make you Superman. My wife and I ran the Pikes Peak marathon 13 times, finishing over 14,000 ft. We did have an advantage over the flatlanders, but on top we were still mumbling idiots.
Oxygen on the sidelines of Bronco games is mostly a psychological benefit. The pool at the AF Academy has the elevation marked on the ends of each lane, to psych out the visiting swimmers.
Jim Berry
RV-10
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Many years ago I remember going up flying with a buddy (we were both passengers) the morning after a heavy night of drinking, we were both pretty hungover (pilot was not drinking with us the night before, don't worry). The thing I remember most vividly about it was that as we climbed up to 12,500 (no oxygen) it was like we were drunk all over again, we were laughing and joking and cutting up and everything was funny, just like a couple high school kids with their first beer. Descending back down again the buzz wore off quickly and the heavy hangover came right back - weirdest thing I've ever experienced.
a "redneck" solution to bottled O2
Sometime when you are up high with a pulse ox try taking off the oxygen and let the PO2 stabilize, then do a couple of minutes of grunt berating.
You will be amazed at how much you can raise the blood PO2 by just grunting hard each breath.
Not recommended for long time periods, but might be helpful in some situations.
Sometime when you are up high with a pulse ox try taking off the oxygen and let the PO2 stabilize, then do a couple of minutes of grunt berating.
You will be amazed at how much you can raise the blood PO2 by just grunting hard each breath.
Not recommended for long time periods, but might be helpful in some situations.
rv9av8tr
Well Known Member
Interesting concept, but short of controlled testing, it's hard to tell if grunting raises the ACTUAL dissolved O2 in the blood by the diaphram increasing the pressure in the lungs or just changes the INDICATION of pulsoximeter by changing the perfusion due to blood pressure changes in the finger....
Its real
The increase in the reading is real. The effect is due to the increased intrathoracic pressure driving the oxygen into the hemoglobin just as going lower drives the oxygen into the hemoglobin.
The pressure is generated by contraction of the intercostal and abdominal muscles against the glottis to create sort of a "pressure vessel" in the thorax and abdomen.
The increase in the reading is real. The effect is due to the increased intrathoracic pressure driving the oxygen into the hemoglobin just as going lower drives the oxygen into the hemoglobin.
The pressure is generated by contraction of the intercostal and abdominal muscles against the glottis to create sort of a "pressure vessel" in the thorax and abdomen.
Hi Flight
It makes you wonder about the regs when you go skiing at 12,000' and you are working your body hard to boot. I know that flat landers tend to have problems when flying in on the morning of a Rockies ski vacation, while the folks that are accustomed to living at 5-6K' don't have a problem.
Having had real life hypoxia event in an F-4 one day, I give it a wide margin. It is nothing to fool with and will bite you before you know it.
It makes you wonder about the regs when you go skiing at 12,000' and you are working your body hard to boot. I know that flat landers tend to have problems when flying in on the morning of a Rockies ski vacation, while the folks that are accustomed to living at 5-6K' don't have a problem.
Having had real life hypoxia event in an F-4 one day, I give it a wide margin. It is nothing to fool with and will bite you before you know it.
AZtailwind
Well Known Member
Live at 7k
I'm in the 1% club of pilots that live at 7,000
Our high chair lift is at 11,500
12,500 is not a problem...for too long
15,000... I have not tested that and won't try
I'm in the 1% club of pilots that live at 7,000
Our high chair lift is at 11,500
12,500 is not a problem...for too long
15,000... I have not tested that and won't try
+1 that it is real. Actually you don't even need to grunt. Many people with chronic lung disease do 'pursed lips breathing' similar to blowing out a candle, because it raises the oxygen content of their blood.
You guys who continue to suggest that living at high elevation gives you immunity scare me. There is a big difference between running, biking or skiing at high elevation, and being able to maintain the executive brain functions needed to fly a plane.
Also, being fit is a 2 edged sword. Fit individuals are actually more likely to develop altitude sickness.
Jim Berry
RV-10
I dunno. I still maintain a monkey can fly an airplane. I remember when Sonny Bono's executive brain function failed him into a pine tree. Is decision making in an airplane more critical than on Everest or a black diamond hill? Or, is it the airplane ego thing popping up again.
The vast majority of people climbing Everest are on O2, and approx. 10% of them die anyway.
I don't believe my plane has an ego
Jim Berry
RV-10
