Beech Beechcraft Bonanza V35 Pilot Operating Handbook page 356

Section X
Safety Information
~ft
Slngle Engine (Piston)
who take certain drugs, may be more susceptible to hyp-
oxia. Susceptibility may also vary in the same individual
from day to day or even morning to evening. Use oxygen on
flights above 10,000 feet and at any time when symptoms
appear.
Depending upon altitude, a hypoxic individual has a limited
time to make decisions and perform useful acts, even
though he may remain conscious for a longer period. The
time of useful consciousness is approximately 3-5 minutes
at 25,000 feet of altitude and diminishes markedly as alti-
tude increases.
Should symptoms occur that cannot definitely be identified
as either hypoxia or hyperventilation, try three or four deep
breaths of oxygen. The symptoms should improve markedly
if the condition was hypoxia (recovery from hypoxia is rapid).
Pilots who fly to altitudes that require or may require the use
of supplemental oxygen should be thoroughly familiar with
the operation of the airplane oxygen systems. A preflight
inspection of the system should be performed, including
proper fit of the mask. The passengers should be briefed on
the proper use of their oxygen system before flight.
Pilots who wear beards should be careful to ensure that
their beard is carefully trimmed so that it will not interfere
with proper sealing of the oxygen masks. If you wear a
beard or moustache, test the fit of your oxygen mask on the
ground for proper sealing. Studies conducted by the military
and oxygen equipment manufacturers conclude that oxygen
masks do not seal over beards or heavy facial hair.
Federal Aviation Regulations related to the use of supple-
mental oxygen by flight crew and passengers must be
adhered to if flight at higher altitudes is to be accomplished
safely. Passengers with significant circulatory or lung dis-
ease may need to use supplemental oxygen at lower alti-
tudes than specified by these regulations.
10-42 May, 1994