Beechcraft C-12C Operator And Technical Reference Manual page 150

TM 1-1510-218-10
b. Replenishing Oxygen System.
1. Remove oxygen access door on outside of
aircraft.
2. Remove protective cap on oxygen system
filler valve.
3. Attach oxygen hose from oxygen servicing
unit to filler valve.
WARNING
If the oxygen system pressure is below 200
psi, do not attempt to service system.
Make an entry on DA Form 2408-13-1.
4. Ensure that supply cylinder shutoff valves
on the aircraft are open.
5. Slowly adjust the valve position so that
pressure increases at a rate not to exceed
200 psi per minute.
6. Close pressure regulating valve on oxygen
servicing unit when pressure gauge on
oxygen system indicates the pressure
obtained using
Servicing Pressure Chart, Figure 2-24.
To compensate for loss of aircraft cylinder
pressure as the oxygen cools to ambient
temperature after recharging, the cylinder
should be charged
approximately 10%
pressure. Experience will determine what
initial pressure
compensate for the subsequent pressure
loss upon cooling.
create little heat. A complete recharge will
create substantial heating.
The final stabilized
should be adjusted
temperature, Figure 2-24.
7. Disconnect oxygen hose from oxygen
servicing unit and filler valve.
8. Install protective cap on oxygen filler
valve.
9. Install oxygen access door.
2-134
the Oxygen System
NOTE
initially
over prescribed
should be used
A small top-off will
cylinder pressure
for ambient
2-115. GROUND HANDLING.
Towing lugs are provided on the upper torque
knee fitting of the nose strut. When it is necessary to
tow the aircraft with a vehicle, use the vehicle tow bar.
1. Do not attempt towing or taxiing of the
aircraft with control surfaces in the
LOCKED position.
2. Do not operate engines while towing
equipment is attached to the aircraft, or
while the aircraft is tied down.
3. When moving the aircraft, do not push on
propeller deicing boots. Damage to the
heating elements may result.
4. When the aircraft is being towed, a
qualified person shall be in the pilot's seat
to maintain control by use of the brakes.
5. When towing, do not exceed nose gear
turn limits. Avoid short radius turns, and
always keep the inside or pivot wheel
turning during the operation.
6. When being moved backwards, do not
apply the brakes abruptly.
7. Tow the aircraft slowly, avoiding sudden
stops, especially over snowy, icy, rough,
soggy or muddy terrain.
8. Do not tow aircraft with deflated shock
to
struts.
2-116. GROUND HANDLING UNDER EXTREME
to
WEATHER CONDITIONS.
Extreme
particular care in ground handling of the aircraft. In
hot, dry, sandy, desert conditions, special attention
shall be devoted to finding a firmly packed parking and
towing area.
mats or an equivalent solid base shall be provided for
these purposes. In wet, swampy areas, care shall be
taken to avoid bogging down the aircraft. Under cold,
icy, arctic conditions, additional mooring is required,
and added precautions shall be taken to avoid
skidding during towing operations.
problems to be encountered under adverse weather
conditions and the special methods designed to avoid
damage to the aircraft are covered by the various
phases of the ground handling procedures included in
this section of general ground handling instructions.
(Refer to TM 1-1500-204-23).
weather conditions
If such areas are not available, steel
necessitate
The particular