On the bottle now

One thing about the hangar community is you meet other pilots; my goal is to learn at least one thing from each one I meet.  Jumping in a cockpit with another pilot and you'll recognize the procedures and checklists, yet to meet two pilots who do everything exactly the same.  My neighbor Bob invited me for a ride along in his Bonanza and showed me a blind-spot I had regarding the use of oxygen.  Thanks to Bob my situational awareness improved.

After living in Colorado for 14 years and climbing too many peaks to list here, then flight training and memorizing FARs pertaining to oxygen use, I've heard of hypoxia; watched dad certify in the altitude chamber at Plattsburgh AFB; and listened to ATC recordings of a hypoxic pilot over western Colorado.  I can recite hypoxia's symptoms, contributing factors, and treatment, and led kids in discussions about high elevation activities at Boy Scout meetings. I've had a few experiences with mild hypoxia while hiking and biking in the high-country, usually aggravated by dehydration. Even with all this awareness, training, and experience, I had a gap.

Bob, my personal oxygen ambassador, invited me to take a ride in his beautiful Bonanza.  He said we'd take it high; he loaded a bottle in the backseat and outfitted me with a cannula.  I love my Cheetah, but she's no straight tail Bonanza, we climbed through 10,000 feet in 4 minutes.  Bob reaches in back and turns up the O2 bottle, then leans over to the glove box grabs a pulse ox sensor and starts checking his levels.  Meanwhile, I'm flying the plane with the cannula coiled up in my lap...thinking to myself, what's up with Bob?

                                      Used SkyOx 4-port system bought from a retiring pilot

Bob was about to teach me something about FAR 91.211 that I will not forget.  5 minutes into the flight, on a standard day, still less than 11,000 feet (cabin pressure altitude), he hands me his oximeter.  My oxygen saturation read 84% and continued to drop steadily, I put on the cannula and watched recovery in under a minute.

$39 pulse Oximeter bought from Amazon

I've flown plenty higher and longer while solo over the mountains without oxygen, and felt fine.  I believed the regulation to be a good guideline, while incorrectly crediting myself for the mile high life and ignorantly congratulating myself for above tree-line stamina.  This attitude is wrong headed, a broken link in my chain.  It's corrected now; let the O2 flow...thank you Bob!

Lesson Learned:

Based on the oxygen saturation readings at 10,000 feet, 91.211 is a regulation, rather than a best practice; using it in place of good judgment is poor judgment.

Part 91.211

(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.

Action:

Oxygen goes on me and my passengers above 10,000 (density altitude).  This means every trip west I'm on the bottle now.

Benefits:

- Better cognitive reasoning - might come in handy

- Stay awake - fair enough

- Avoid altitude sickness symptoms like headaches - good

- Huffing O2 in-flight result in any stamina boost on the trail? - Seems like it wouldn't hurt

It might have been interesting to fly the edge of the regulation with one pilot on gas and the other not; taking oximeter measures, though I need no more convincing.