Thursday, May 09, 2013

Ramblings Including Oxygen

This is a story about helping to train a pilot who was hired to take my job after I leave. I want to keep this job now, but then I want every aviation job. I cried handing in my resignation from a flight instruction job to work at an airline, and I once worked three different flying jobs at once because I loved them all. Crazy girl. My resume is kind of hard to follow, and my tendency to take temporary jobs probably makes it look worse. But look! I get to fly an airplane!

The new pilot isn't on line yet. He doesn't have previous time on the aircraft type, so the insurance company has said he can't fly it until he has logged ten hours. (I happened to have flown the type before, logging time in exchange for using my navigational skills to keep the owner from getting lost. Aviation sluttery has its merits. And wow, modern GPS units have totally devalued my once-marketable excellent navigational skills.) So he is on this road trip to fly the plane and learn the ropes while I serve as the insured pilot in command. He flew the repositioning flight out here from base and handled the airplane well, but doing the part of the job that isn't getting from A to B is going to be more challenging. We've settled the FBO bill for ramp fees and fuel, walked around the airplane, and packed everything into the cargo area. I have pared down my road trip packing list (no computer!) in preparation for this, but at the last minute the boss decides we will leave him behind because we're doing high altitude work, and it may be difficult to get an oxygen refill on this holiday weekend. We literally put him on a bus.

One of the things I like about aviation is something some people might hate: nothing can be taken for granted. The airplane won't give me a pass because I flew it really well yesterday, or because it knows I know how to handle an engine failure better than that, or because it likes the look of my ass. I have to fly it correctly right now for all values of now. And the things that non pilots take for granted during their workday: access to water, restroom facilities, food, oxygen, heat, not having a mountain come through your office window... they all have to be planned.

This airplane is non-pressurized, so we have to bring and mete out compressed oxygen for all flight above 10,000'. (US rules are different, but it's 10,000' here). Technically we can be between 10,000' and 13,000' for 30 minutes without oxygen, but company policy is just to use the oxygen, because it's harder to plan exactly how long we'll be up there than it would be if we were an A to B type operation. Curiously, Canadian air law dictates that High Altitude Training is required for flight crew operating aircraft above 13,000 feet ASL before the first assignment on a pressurized aircraft and every three years thereafter. As far as I can see, this is a huge loophole through which I can fly my unpressurized aircraft at flight level 220. I assume that the framers of that law didn't consider that there are crews out here operating unpressurized aircraft in the flight levels, and not that they really thought only crew of pressurized aircraft need altitude-specific training.

Fortunately my company doesn't stop at minimum training. I was assigned to present a seminar covering the required material. Here's a little table I should know better giving time of useful consciousness at various altitudes without supplemental oxygen./p>

FL 150 30 min or more
FL 180 20 to 30 min
FL 220 5-10 min
FL 250 3 to 6 min
FL 300 1 to 3 mins

These are pretty variable between individuals. The body has an ability to acclimatize, but acclimatization takes weeks and is lost soon after descending so it doesn't really apply to flight. For example, Mt. Everest is pretty close to 30,000' tall--i.e. almost reaches FL300--but humans have climbed it without oxygen. One of my own co-workers spent a week at Everest base camp and didn't become an idiot after 20-30 minutes. I have no idea where I fall. I'm pretty fit, but does tolerance to a low partial pressure of oxygen relate to long distance running and cycling ability? We often work in the 5-10 minute zone of that chart, which is kind of a sweet spot, because I can descend from there to a level where I can breathe indefinitely in five to ten minutes, depending on how viciously I'm willing to cool the engines.

Today, after I called out in (normal) descent, "through ten thousand, oxygen off," my co-worker said, "Taking off oxygen is like taking off ski boots." Oxygen is essential, but nice to get the mask or cannula off after a while.

Oh and before you ask where I am going or about my new job: there isn't one. New guy couldn't handle the lifestyle so I came back to work again. I love the lifestyle. Five fifteen a.m. start tomorrow, so bed now.

1 comment:

Cedarglen said...

Thanks for another excellent post. you will forgive me, please, but after reading your posts for a couple of years, I just don't see you as a "Happy Camper," flying an airliner through points A, B, and C., then rinse and repeat for the rest of your life. If that's what YOU want, go for it, but...
Your notes on O2 use in an unpressurized airplane at altitude are important - and I delighted to hear that your company (apparently) does not quibble about O2 use. Who the heck wants a bubble-headed pilot driving their very expensive (if old - I think) airplane. If one thinks that they need supplemental O2 at 8,000 feet, use it! When closer to 10,000 feet and wondering if you need to tie a finger around your string to remember, ahem - use the O2. Duh? More than a few 'experts' consider flying at altitude - and without supplemental O2 to be as bad, perhaps worse, than flying with EtOH in your system. Those who fly under those conditions - like you do - are well advised to know their own physiological systems well - and before flying 'high.' They won't let you attempt a flight without fuel, and O2 IS part of the fuel load. Nuff said and thanks for a great post.