Mxsmanic wrote:
Robert M. Gary writes:

I usually do. Many of the rental planes keep a bottle in the back too.
I have a large bottle I bring for the family 4 place, but also a
smaller, more manageble bottle with just one port for myself in the
Mooney.

Is this just a device you set down on the seat beside you, or what?
How long does one bottle last? I presume it's automatically regulated
so that you use only as much oxygen as you need for the altitude?

My personal one sits on the seat next to me. If I"m flying with the
family the big one sits on the back of my seat (it comes with a special
strap). There are 4 twist adjustors and each line has a gauge on it
that is measured in altitude. So you turn up the adjustor until the
ball bounces up to the altitude you are flying at. From there you go by
personal preference. My wife likes a bit more O2 so I set her higher.
If the boys are starting to fight with each other I'll turn theirs down
a bit. My youngest likes a bit less anyway. At night I turn mine up a
bit more for better night vision.
Its important to remember to turn them off as you start down for
landing or you'll waste your O2. Amount of O2 used goes up quickly with
altitude. At 13,000 feet with all 4 of us using O2 my bigger bottle
lasts about 10-12 hours down at 10,000 its probably good for 20 hours
with 4 people. The difficult thing is that if you are planning a long
trip do you fill now or later? Remember you don't pay for the O2, just
the labor to fill it, which is the same for a top off vs a full tank.
So you want to run it down a bit before filling.
Also, if you want to **** someone off **really quick* turn their O2 way
up. It burns the inside of your nose pretty good. I also carry an
emergency O2 mask in case I have a bad cold but have yet to ever use
it.
-Robert