Light Aircraft (GA) and altitude.

What do folks in non pressurized planes do at altitude? I believe the FAA rule is for the pilot to be on O2 above 10,000 feet.

If flying over the Rocky Mountains, that would pretty much require that they don oxygen masks, no?

Do other systems exist besides a full mask? Could a pilot and passengers get by with the trickle O2 feed into the nose that many people in hospitals use?

A second question – It’s been a while since I’ve been in anything smaller than say a Cesna Caravan. If I recall, you could talk to your fellow passengers above the noise. What about a 172? How about a Beech Barron 58? Would everyone plug into an intercom system?

(yes I am stuck at home with a cold playing MS Flight Sim 2002)

It used to be in the old days :::

O² at 10K at night

Flew in the West mountains all the time with no O² until 14K or above. But I was used to it. Plus I have over sized lungs.

Took a C-310 Turbo to 31K ( just barely ) with just simple nose & mouth cover with a re-breather bag.
Worked aerial mapping a lot to 20K with just a nose cannula ( like in a hospital ) or just a tube stuck in our mouths.

Prolly not legal but this was long ago.

Always remembered and never forgot I was bad stupid at high altitudes so I planned accordingly.

Was at 22K one time in Ohio and ran out with about 10 minutes to go on the flight line. We finished it and then requested lower from ATC with the note that we were out of O² and he cleared us down to 16K and started to give additional instructions and I told him I could not copy until I got down to where I was not stupid anymore. He just cleared a block and said to give him a call when I could think again. He was a good controller to work with.

Intercom is easier in most light planes but you can communicate without if you really really want to.

FAR 91.211 gives the O2 usage requirements for general aviation. If you’re above 12,500’ for more than 30 minutes the crew must use oxygen. Above 14,000 the crew has to use it at all times. Above 15,000’ it must be provided to everyone on board (although not necessarily used by passengers).

Several systems are available for non-pressurized aircraft. I think the most common is a cannula system that looks like medical oxygen delivery. I’ve used it, and usually combine it with an blood oxygen saturation monitor.

As to your second question, most people use headsets these days. That wasn’t the case years ago, but now it’s relatively unusual not to. I’ve even flown in Piper Cubs that had intercom systems installed. However, one can still converse without them in most planes, but it’s quite loud.

I wouldn’t call it ‘quite loud’, but it’s definitely louder than in a car. In dad’s 172 and 182 we were able to converse easily without headsets, though with slightly elevated voices. We eventually did start using headsets, which was much better.

Glider pilots routinely carry supplemental oxygen systems when it’s possible to climb above 10,000’ (and in many places in the US West, lift to twice that altitude is possible).

The hot setup these days is an electronic pulse demand system. This uses a nasal cannula; when you inhale the system senses the slight drop in pressure and gives a pulse of oxygen whose duration depends on the current altitude. The result is that close to 100% of the oxygen is useful, meaning that a bottle lasts much longer than with other delivery schemes.

Yes, you can fly in a 172 without a headset and you can talk to your passengers. Sometimes I decide to do just that - you can switch the radio to a speaker overhead, and there’s a little hand-held microphone you use for making radio calls.

I like it, because somehow everything feels more “real” without the headset, if that makes any sense. Also, my wife doesn’t like wearing the headset because she is more prone to motion sickness when she’s wearing it.

Can’t say anything about the oxygen at altitude - I’ve never flown higher than 6500’ and usually potter around at about 1500’. I guess I must be afraid of heights.

Thanks everyone.

I thought that there must be a different system for those that hit 10-15k feet. I see the planes fly over my house and I’m already at 11k.

I’m having great fun flying the Baron 58 in a flight sim (not that I really think I could fly one) and the altitude issue gave me pause.

Mach Tuck hit the oxygen crew usage requirements. With regard to the type of oxygen delivery system required, you have to look to aircraft certification regulations, specifically 14 CFR §23.1441-1449 and 14 CFR §25.1441-1449. Here’s a brief summary:

In unpressurized aircraft, a cannula like you’d see on a hospital patient is sufficient to altitudes up to 18,000 feet. Between 18,000 and 25,000 feet, the crew must use a continuous flow mask that looks a bit like the ones flight attendants use during their passenger safety briefings. Above 25,000 feet the mask must be a face-sealing diluter-demand or pressure-demand mask that looks more like a fighter-pilot oxygen mask. These masks are capable of providing oxygen at high concentrations, and, in the case of a pressure-demand mask, positive pressure. The name of the game is maintaining sufficient partial pressure of oxygen to the flight crew so we don’t get all woozy and giggly.

Tests have been done with a cannula and an oximeter to altitudes over 25,000, showing blood oxygen saturation above 94%. But regulations are conservative, and don’t allow this in aircraft.