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I am taking my mom for a trip over the grand canyon. My mom lives at sea level, whereas I live at 5000ft, and workout at 8000ft daily.

The VFR lowest route over the Grand Canyon is 11,500ft MSL. If I am flying over this with my mother and she starts to exhibit signs of hypoxia, what are my options?

It is the law to remain at the prescribed altitudes and headings while flying around the Grand Canyon. That being said, obviously passenger safety comes before anything else. If my mom gets sick, I would have to drop in altitude, but what kind of consequences would I face for this?

In the event of hypoxia in one of these corridors, what would be the best way to deviate while remaining safe and courteous?

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    $\begingroup$ Also, can she stay with you at 5000-8000 feet for a few days before the flight? Partial or gradual acclimatisation may help her, even a little. $\endgroup$ – Brian Drummond Apr 8 '15 at 10:19
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    $\begingroup$ As a sea level guy myself, high altitudes are no joke. I'm fine flying at up to around 7,000 feet for an hour or 2. 9,000 for a couple hours or more and I get headaches. 11,000 for even just an hour and I'm sick the rest of the day. I spent a day at Lake Tahoe (6,000) and was in sad shape by the end of the day, didn't feel better until we got off the mountain. $\endgroup$ – Brian Knoblauch Apr 8 '15 at 15:22
  • $\begingroup$ Your first two paragraphs are answered well so far. The second two really sound like they should be a separate question, related to this one. $\endgroup$ – fooot Apr 8 '15 at 16:38
  • $\begingroup$ If I don't change anything, I cannot save the edit. I edit to improve a post, but anyone can disagree and revert. $\endgroup$ – Farhan Apr 8 '15 at 18:17
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    $\begingroup$ @IanRingrose - Do I think my mom is going to get sick? No. It it a possibility that I should be prepared for, yes. Is "impressing mom" the only reason that I want to take this trip? Of course not. I think this flight will be a fun challenge that I am prepared for. I also plan to land at Marble canyon for a few minutes which is inside the canyon at 3000ft. Stopping off at a low altitude will also help alleviate any "danger." $\endgroup$ – Keegan Apr 9 '15 at 14:49
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First, let's be crystal clear on something: A person experiencing symptoms of acute hypoxia is an emergency which requires immediate action to ensure the safety of that person. In an in-flight emergency requiring immediate action, the pilot in command may deviate from any rule … to the extent required to meet that emergency. (FAR 91.3 (b)).

So if you're over the Grand Canyon at 11,500 feet and your mother starts showing signs of hypoxia you key the mic and let ATC know you have a passenger showing signs of hypoxia, tell them you are descending to a lower altitude, and ask for vectors to an airport where you can land. If they give you any trouble about it you respond with "N12345 is declaring a medical emergency".


All that said, there are sensible things you can do to mitigate the risk of hypoxia and avoid the need to declare an emergency.
If you intend to spend an extended period of time at altitude (which I personally define as "Over 10,000 feet" for an average healthy non-smoker):

  • Bring a portable oxygen system
    Ideally with enough cannulas/outlets for yourself and your mother/other passengers).
  • If a full oxygen system isn't an option bring one or more "boost cans"
    These can provide temporary/limited relief for symptoms of hypoxia – probably enough to get yourself back on the ground, or at least to a lower altitude.
  • Carry a relatively inexpensive pulse oximeter
    Check your SpO2 periodically to catch hypoxia early - before clinical symptoms develop.
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    $\begingroup$ Hypoxic hypoxia is an emergency for the aircrew, but not so much for the passengers. The only time a hypoxic passenger at that altitude would worry me is if my aircraft was supposed to be pressurized. There are certainly safe levels of hypoxia that will make you feel weird, but not have any lasting effects. You can live indefinitely at 11,500ft. However, DCS and carbon monoxide poisoning are completely different and would require immediate medical attention. $\endgroup$ – Rhino Driver Apr 9 '15 at 1:49
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    $\begingroup$ @RhinoDriver I have to respectfully disagree with the assessment that a hypoxic passenger is not an emergency. Hypoxia in an otherwise healthy adult is not something to be taken lightly: SpO2 < 90% triggers medical intervention (supplementary oxygen) in most clinical settings, and by the time symptoms of hypoxia become apparent SpO2 is may be as low as the mid-80% range. That is unlikely to cause lasting harm if reversed, but you want to be sure it doesn't get worse so your priority should be taking swift action (providing oxygen or descending) to ensure your passenger's safety. $\endgroup$ – voretaq7 Apr 9 '15 at 3:02
  • $\begingroup$ Sure I'd agree with your general assessment; however, in this instance at 11,500ft any hypoxia would be very minor and I would suggest a greater emergency would exist if you found yourself making a rapid descent below MSA. We actually train to recognize the symptoms of hypoxia, and fly in a simulator where flight docs drop our O2. Aside from being hilarious watching a drunk guy try to fly, the experience is invaluable training that helps you recognize your own symptoms. I got as low as 85% without further incidence, and all symptoms are relieved immediately once back on O2. $\endgroup$ – Rhino Driver Apr 9 '15 at 3:11
  • $\begingroup$ @RhinoDriver 11,500 feet won't be a problem for most people. If you have a symptomatic passenger though they're clearly not most people: You can't say they're fine and the hypoxia is "minor" if their lips are turning blue or they're disoriented and babbling. The number on the altimeter has no bearing on this decision. It's a purely clinical call based on symptoms, and it should be a pretty easy one for a pilot to make (assuming they're not hypoxic too). $\endgroup$ – voretaq7 Apr 9 '15 at 3:37
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    $\begingroup$ I think we're really on the same page here. If someone's lips are blue or they're babbling incoherently, then there is a serious problem. However, when most people talk about hypoxia symptoms, the ones you can usually self diagnose are things like euphoria, rapid heart beat, hot flashes, if you've made it to babbling then you're in some deep trouble. I just don't believe at 11,500 that a normal healthy person will experience hypoxia symptoms like you've described. Babbling at that altitude would like indicate other serious underlying medical conditions. $\endgroup$ – Rhino Driver Apr 9 '15 at 5:40
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You don't have to divert, in fact it may be a bad option depending on conditions (I would recommend you don't go if conditions will make diverting dicey though). You can treat the hypoxia with low cost bottled oxygen supplies specifically made for this situation.

At 11,000ft it's unlikely lack of oxygen will make your mother really ill, a top of oxygen is all she's likely to need. A pony bottle should let you get through your flight if she exhibits some symptoms, at 12 bucks a pop you can buy 2 just in case.

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  • $\begingroup$ That bottle says it contains enough oxygen for 120 inhalations. How long (how much flight time) would that last? $\endgroup$ – ChrisW Apr 8 '15 at 17:07
  • $\begingroup$ Thanks for the answer. And I'll see if I can get one of those bottles locally (the flight is in two days). If not I guess I'll just bring a few barf bags... $\endgroup$ – Keegan Apr 8 '15 at 18:17
  • $\begingroup$ @ChrisW Most places say that those bottles last about 10 minutes. For me, one calm inhale/exhale is about 3-4 second. So that bottle would last me about 7 minutes. Assuming they don't actually last that long, I would feel comfortable assuming there's 5 minutes usable in there. $\endgroup$ – Keegan Apr 8 '15 at 19:18
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    $\begingroup$ It's 10 minutes if you're constantly sucking on it, but it's unlikely someone needs that much at that altitude. More likely just a few pulls a minute would be enough to alleviate symptoms. Of course you may be able to rent a full portable oxygen system from a local FBO. $\endgroup$ – GdD Apr 8 '15 at 19:32
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    $\begingroup$ The boost bottles can last quite a while if you're just having a passenger puff on them occasionally to keep SpO2 above 90% while you work out a diversion - they're somewhat less practical for the pilot though (because they occupy one of your hands) $\endgroup$ – voretaq7 Apr 9 '15 at 3:05
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The simple answer is to rent or buy a supplemental O2 system for Mom.

Don't fake this one. As Voretaq7 said in the first answer, "A person experiencing symptoms of acute hypoxia" Focus on the word "acute". Just having your Mom feeling a little light-headed is probably not going to hold up as a valid reason to divert lower in any faa action. And if their google-fu is good and they find this website, you will not be able to claim that you were not aware of the potential for a problem.

The reason for my warnings: They are serious about the altitude restrictions over the Grand Canyon. Diverting should be reserved for a truly unexpected emergency. Just get the supplemental O2 system and you are covered.

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    $\begingroup$ Yes, to clarify a bit when I say "symptoms of acute hypoxia" I'm talking the major symptoms: disorientation, obvious cognitive impairment, cyanosis (blue fingers/lips), etc. – Before that point you may want to start planning how you're going to get lower, but you're not at the threshold I would personally consider an emergency. $\endgroup$ – voretaq7 Apr 9 '15 at 3:16
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    $\begingroup$ I ordered two of the disposible bottles of O2 that people linked. I also remember my mom going on a commercial helo ride over the canyon a few years ago and she never mentioned any problems with that. I honestly think she should be fine, but like you said, I do know the risks, and I don't want to put her (or my pilot licence and AFROTC career) in danger. $\endgroup$ – Keegan Apr 9 '15 at 3:58
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In principle at least, you can begin to experience hypoxia at 5000ft. By 10,000ft, it's affecting your eyesight, and probably starting to affect your judgement a little. At 15,000ft, your judgement can be measurably impaired, and you'll often experience euphoria, so you can't TRUST your judgement even if you think everything is okay.
Your personal experience and thresholds may vary.

FAR 91.211 spells out supplemental oxygen requirements. At 11,500, you're close enough to the FAR regs (12,500) that you really ought to be carrying supplemental oxygen. These regs are known to be very liberal. Bring some oxygen for both of you and no worries.

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  • $\begingroup$ But as someone acclimated to 8,000ft, I am much less likely to start experiencing symptoms at 11,500 than someone who just came from sea level. $\endgroup$ – Keegan Apr 8 '15 at 18:10
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    $\begingroup$ @SpongeBob - Less likely doesn't mean it cannot happen. Being prepared could mean the difference between making it back safely or ending up on the canyon wall. $\endgroup$ – Thebluefish Apr 8 '15 at 21:40
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    $\begingroup$ The 5,000ft number comes from the aeromedical chapter on hypoxia, and they say it primarily affects night vision. $\endgroup$ – rbp Apr 9 '15 at 1:04
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    $\begingroup$ A pretty large exaggeration. 10k feet should have enough oxygen to completely alleviate hypoxia symptoms (save perhaps night vision). Not only is an emergency descent to 10k feet in our emergency procedures for hypoxic crew members, but our flight doctors have briefed us the same as well. $\endgroup$ – Rhino Driver Apr 9 '15 at 2:02
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    $\begingroup$ The reason 10k feet is used as a floor is that you can probably hang out there for a while (probably up to an hour) safely. Acute Mountain Sickness sets in for most people at around 8,000ft when they're continuously exposed. High Altitude Cerebral Edema and High Altitude Pulmonary Edema begins at prolonged exposures above 10,000ft for non-acclimated people (acclimation takes days, sometimes weeks). $\endgroup$ – Calphool Apr 9 '15 at 17:59

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