TM 1-1520-238-10
5-10
Change 9
Section V.
AIRSPEED LIMITS MAXIMUM AND MINIMUM
5.12 AIRSPEED OPERATING LIMITS.
See figure 5-2 to determine the never exceed velocity
(VNE) as a function of weight, altitude, and temperature.
Additional airspeed limits are:
a. Maximum airspeed during autorotation is 145
KTAS.
b. Maximum airspeed with one engine inoperative
shall not exceed the greater of:
(1) 67% of VNE determined from figure 5-2 sheet 1
using the GROSS WEIGHT line.
(2) The speed for minimum power determined
from the cruise charts in Chapter 7
or Chapter 7A
using the MAX END/MAX R/C lines.
c. The NOM SPD values depicted on the stabilator
position (STAB POS) indicator placard (fig 5-1) shall be
observed as maximum indicated airspeeds during manual
stabilator operations.
d. Maximum rearward/sideward flight speed is 45
KTAS for all gross weights.
e. Maximum airspeed for searchlight extension is 90
KIAS.
f. Maximum airspeed with symetrically loaded exter-
nal fuel tanks (2) installed is 110 KIAS and (4) installed is
65 KIAS.
g. Jettison of external armament stores is not autho-
rized except for emergency conditions, and then only from
unaccelerated flight during:
(1) Maximum airspeed for stores jettison is 120
KIAS, or
(2) Level flight – Hover to 40 KIAS (minimize side
slip), or
(3) Level flight – 40 to 120 KIAS (ball centered), or
(4) Descents (0 fpm to full autorotation) 80 to 100
KIAS (ball centered).
h. Jettison of external fuel tanks is not authorized ex-
cept for emergency conditions, and then only from air-
speeds less than 100 KIAS. Jettison from level flight if
possible, and if not, jettison at an airspeed which mini-
mizes the rate of descent at the time of jettison.
5.12.1 Airspeed Operating Limits Chart.
Referring to
figure 5-2 sheet 1, note that free air temperature lines and
pressure altitude scale are provided in the upper grid, and
gross weight lines and true airspeed scale on the lower
grid. Using the observed free air temperature and altitude
obtained from the aircraft instruments and the calculated
aircraft weight, enter the chart as directed in the chart ex-
ample. Determine maximum true airspeed at the left side
of the lower grid. To determine the maximum indicated air-
speed (pilots gauge), refer to figure 5-2 sheet 2 and enter
as directed in the chart example with the true airspeed
and density altitude determined from figure 5-2 sheet 1.
