It's very important to remember to breathe through your nose. My older
nose doesn't always stay open and I frequently find myself breathing
through my mouth. I added a little plastic band with 2 holes in it, to
the nasial tubes so that they are spread out a bit. Works great. Don't
forget to gently blow back into these tubes when pre-flighting your
oxygen equipment, should get resistance, easy flow means one of the
little bladders is ruptured. These things are only good for 200 hours
of use, so about every 4 years, through it away and buy a new one.
Nelson says it's good up to 18K, above that he recommends a mask,
believe the Feds agree.
JJ

Roger Worden wrote:
On the advice of fellow club members I ordered an oxygen-saving
cannula,
flow meter, and connector to use O2 in a club ship. When I placed the
order
I was advised by the vendor that regulations require a MASK in the
ship, not
just a cannula. He mentioned some situations wherein a mask would be
better,
e.g. if one has a head cold, if one is panicking and breathing
through the
mouth, etc. Makes sense, but that doesn't mean it's required by the
FAA. I
looked it up in FAR/AIM, but I'm not finding a CFR that requires a
mask in
an unpressurized aircraft. 91.211(b)(ii) does, but it's for
pressurized
cabin aircraft.

I haven't bought a mask bit I might if it's wise or required. Seems
to me
that to switch from cannula to mask you'd either need a Y and shutoff
valves, or quick-connects.

Comments? Advice?