Pressurized flight is prohibited due to a
cracked windshield. Conduct flight with
the CABIN PRESS switch in the DUMP
position and the BLEED AIR VALVE
switches in the ENVIRO OFF or PNEU
For further information on cracked
windshield procedures, see the RC-12
Series Maintenance Manual.
Section VIII. OTHER LIMITATIONS
5-35. MAXIMUM DESIGN SINK RATE.
The maximum design sink rate below 13,500 lbs.
gross weight is 600 feet per minute. The maximum
design sink rate above 13,500 lbs. gross weight is 480
feet per minute.
5-36. INSTRUMENT LANDING SYSTEM LIMITS.
During ILS approach do not operate the propellers
in the 1750 to 1850 RPM range.
5-37. INTENTIONAL ENGINE CUT SPEED.
Inflight engine cuts below the safe one-engine
inoperative speed (Vsse, 107 KIAS) are prohibited.
5-38. LANDING ON UNPREPARED RUNWAY.
Except in an emergency, propellers
should be moved out of reverse above
40 knots to minimize propeller blade
minimize stress imposed on propeller,
engine and airframe. Care must be
exercised when reversing on runways
with loose sand or dust on the surface.
Flying gravel will damage propeller
blades and dust may impair the pilot's
forward visibility at low aircraft speeds.
5-39. MINIMUM OIL TEMPERATURE REQUIRED FOR
Engine oil is used to heat the fuel upon entering the
fuel control. Since no temperature measurement is
available for the fuel at this point, it must be assumed to
be the same as the FAT. The minimum oil temperature
graph (fig. 5-3) is provided for use as a guide in preflight
conditions, to allow the operator to become aware of
operating temperatures where icing at the fuel control
could occur. If the plot should indicate that oil
temperatures versus FAT are such that ice formation
could occur during take-off or in flight, anti-icing additive
per MILI-27686 should be mixed with the fuel at refueling
to insure safe operation. In the event that authorized
fuels (Prist) are not available the limitation of this chart
Anti-icing additive must be properly
deterioration of the fuel cell. The
additive concentration by volume shall
be a minimum of 0.060% and a
concentrate is contained in Chapter 2,
JP-4 fuel per MILT-5624 has anti-icing additive per
MILI-27686 blended in the fuel at the refinery and no
further treatment is necessary. Some fuel suppliers blend
anti-icing additive in their storage tanks. Prior to
refueling, check with the fuel supplier to determine if fuel
has been blended. To assure proper concentration by
volume of fuel on board, blend only enough additive for
the unblended fuel.