Airmail

Airmail

In Response to Kevin Ware’s “A Medical Look at Hypoxia” (December)

I enjoy your articles in Twin & Turbine and had a question regarding your most recent. After flying a Baron 58 for 22 years, I recently acquired a JetProp and enjoy it immensely. My aircraft is equipped with an emergency O2 bottle right behind the co-pilot seat. As you pointed out, supplemental oxygen via cannula can be a great help. My question is, do you have any specific recommendations for an oxygen system that I can place behind my seat and provide a decent flow via nasal cannula that is easily portable and easy to refill? It would be my preference to leave the emergency system intact and fully charged. I still have the oxygen saver and mustache cannula with flowmeter that I used with the Baron. The systems I looked at online seemed quite bulky and quite costly for what they provided. What’s your best advice? Thanks.

Stuart Bloom

Kevin Ware Reply: Congratulations on the JetProp purchase. I would buy something like the nine-cubic-foot Sky Ox tank from the likes of Sporty’s. It will give you more than 10 hours at the low flow you will need and weighs only 7 pounds. Over time, I have purchased a couple of tanks of that general type. I have also used medical-type portable O2 tanks, which also worked well. 

Get all refills done through whatever O2 supplier your hospital is using. At my last hospital, their supplier was the local welding place, and they filled up all my, by comparison, silly little tanks for around $7 each. 

__________________________________________________________________________________________________

In Response to Kevin Ware’s “A Medical Look at Hypoxia” (December)

Great article on the potential for hypoxia even though ensconced in a nice pressurized cabin. I was wondering about just one thing: You mention using a portable medical oxygen tank and say it will work just fine in a heated cabin. I know you were referring to potential moisture freezing, but it caused me to wonder about something else: If the cabin depressurized and it was suddenly at 28,000, is the “medical” bottle rated for that? Or higher? At 30,000 feet, the atmospheric pressure is less than 30 percent of what it is at sea level. Does that have any impact on the integrity of the bottle? Are there differences in the construction of the valves or bottles between the portable medical bottle and the bottle specifically designed for aviation uses? (And for all I know, they might be exactly the same).

Ken Karas

Kevin Ware Reply: Good question. The suggestion in the story, however, was not necessarily to buy a “medical” bottle, but rather have the portable aviation bottle, presumably purchased from the likes of Sportys, filled by a medical supplier. 

Having said that, and having been around medical O2 bottles for most of my professional life, there has never been any difference I could see between the two. I have personally used them interchangeably without any problem up to FL220 in unpressurized aircraft. I would defer, however, to someone more expert on the specifics of O2 bottle construction than myself. Thanks for the feedback.

About the Author

Leave a Reply