TM 55-1510-221-10
Section VIII. OTHER LIMITATIONS
5-35. MAXIMUM DESIGN SINK RATE.
The maximum design sink rate is 500 feet per
minute.
5-36. INSTRUMENT LANDING SYSTEM LIMITS.
During ILS approach do not operate the propel-
lers in the 1750 to 1850 RPM range.
5-37. INTENTIONAL ENGINE OUT SPEED.
Inflight engine cuts below the safe one-engine
inoperative speed (V
sse
- 109 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 erosion, and
during crosswind to minimize stress
imposed on propeller, engine and air-
frame. Care must be exercised when
reversing on runways with loose sand or
dust on the surface. Plying 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 FLIGHT.
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 OAT. The minimum
oil temperature graph (fig. 5-3) is provided for use as
a guide in preflight planning, based on known or
forecast operating 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 OAT
are such that ice formation could occur during take-
off or in flight, anti-icing additive per MIL-I-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
apply.
Anti-icing additive must be properly
blended with the fuel to avoid deteriora-
tion of the fuel cell. The additive concen-
tration by volume shall be a minimum of
0.060% and a maximum of 0.15%.
Approved procedure for adding anti-icing
concentrate is contained in Chapter 2,
Section XII.
JP-4 fuel per MIL-T-5624 has anti-icing
additive per MIL-I-27686 blended in the
fuel at the refinery and no further treat-
ment 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.
5-11
