Chapter 5 - Limitations

Question 1

Rotor Speed N_R (%)

Answer 1

110 - Maximum (>110 red)

105-110 - Transient (yellow)

105 - High Rotor Warning Annunciated

94-104 - Normal (green)

0-93 - Transient (red)

Question 2

Engine Oil Pressure

and

NOTE

Answer 2

120 - Maximum (>120 red w/ box)

23-120 - Normal (green)

23 - Minimum (<23 red)

NOTE

It is normal for oil pressure to be high during first start when oil is cold. Oil pressure should return to normal limits after 5 minutes of operation at idle. Do not accelerate above ground idle until oil pressure can be held at or below maximum limit throughout acceleration.

Question 3

Hydraulic Pressure (PSI)

Answer 3

>3410 - Transient - permitted for 5 sec (yellow) (>5 sec red w/ box)

3310-3400 - Transient - permitted for 5 min (yellow) (> 5 min red w/ box)

2750-3300 - Normal (green)

1260 - Minimum (<1260 red w/ box)

Question 4

Engine Starter Limitations

(Explanation)

Answer 4

The Air Turbine Starter (ATS) is capable of making the number of consecutive start cycles listed below, when exposed to the environmental conditions specified, with an interval of at least 60 seconds between the completion of one cycle and the beginning of the next cycle.

A starting cycle is the interval from start initiation and acceleration of the output drive shaft, from zero rpm, to starter dropout. The 60 second delay between start attempts applies when the first attempt is aborted for any reason and it applies regardless of the duration of the first attempt. If motoring is required for an emergency, the 60 second delay does not apply.

Question 5

Engine Starts At Ambient Temperatures of 61° F (16° C) and Below

Answer 5

Two consecutive start cycles may be made, followed by a 3 minute rest period, followed by two additional consecutive start cycles. A 30 minute rest period is then required before any additional starts.

Question 6

Engine Starts At Ambient Temperatures Above 61° F (16° C)

Answer 6

Two consecutive start cycles may be made. A 30 minute rest period is then required before any additional starts.

Question 7

Dual Engine Starts

Answer 7

Dual engine starts are prohibited due to insufficient IPAS air.

Question 8

Engine Temperature Limitation TGT (°C) With SE Picture

Answer 8

949 - Maximum (>949 red)

904-949 - Transient, 12 sec (yellow)

880-903 - Contingency, 2.5 min (yellow)

847-879 - Max rated power, 10 min (yellow)

851 - Maximum during start

794-846 - Intermediate rated power, 30 min (yellow)

793 - Maximum continuous power

0-793 - Normal (green)

Question 9

Engine Temperature Limitation TGT (°C)

NOTE

With DE Verticle Tape Picture

Answer 9

Each engine incorporates a TGT limiter control which limits engine operation according to the following indicated TGT value:

Dual Engine: 879° ±5° C

Single Engine: 903° ±5° C

Question 10

Engine Power Turbine Speed N_P (%)

and

NOTE

Answer 10

119 - Maximum (>119 red w/ box)

114 - Engine overspeed annunciated

105-119 - Transient, 12 sec (yellow, w/ box at 114)

0-104 - Normal (green)

NOTE

• It is not abnormal to observe a NP split between ENG1 and ENG2 during autorotational descent when the engines are fully decoupled from the transmission. An increase from 100% to 105% is possible.
• Maximum NP vertical tape indication is 120%.

Question 11

Engine Gas Generator N_G​

Answer 11

106. 0 - Maximum (>106.0 red)
107. 1-106.0 - Transient 12 sec (yellow)
108. 1-105.0 - Normal (green)
109. 0 - Minimum engine out warning annunciated (<63.0 red w/ box)

Question 12

Engine Torque TQ (%) With N_R <50%

Answer 12

30 - Maximum (>30 red)

0-30 - Normal (green)

Question 13

Engine Torque TQ (%) With NR <90%

Answer 13

70 - Maximum (>70 red)

0-70 - Normal (green)

Question 14

Engine Torque TQ (%) DE

Answer 14

115 - Maximum (>115 red)

101 - 115 (Transient 6 sec (yellow)

0-100 - Normal (green)

Question 15

Engine Torque TQ (%) SE

Answer 15

125 - Maximum (>125 red)

121-125 - Transient 6 sec (yellow)

111-120 - Single engine contingency, 2.5 min (yellow)

110 - Single engine continuous power (green)

0-110 - Normal (green)

Question 16

Auxillary Power Unit (APU)

CAUTION

Answer 16

Avoid prolonged operation at 94% - 96% NR with the APU running. The APU clutch will oscillate from engaged to disengaged. This creates high loads on the clutch and shall be avoided.

Question 17

APU Operating Limitations

Answer 17

APU operation is prohibited during normal flight. After a fault or aborted start, wait 30 seconds after APU has stopped before attempting another start. After 2 consecutive start attempts, wait 20 minutes before third start attempt. No more than 3 start attempts are permitted in one hour.

Question 18

Extended APU Ground Operations

Answer 18

During prolonged ground operations greater than 30 minutes, observe XMSN TEMP 1 and XMSN TEMP 2 on the SYS page. If the temperatures exceed 140° C, the APU shall be shutdown and the transmission fluid allowed to cool for 30 minutes prior to resuming APU ground operations; or transmission fluid may be cooled by operating an engine with rotor turning. There is no requirement to remove transmission side panels during extended APU ground operations. However, the transmission fluid will not get as hot under high ambient temperature conditions if the side panels are removed.

Question 19

Weight Limitations

Answer 19

The aircraft maximum gross weight is 20,260 pounds, except for non-tactical ferry flights, which may not exceed 23,000 pounds.

Question 20

Airspeed Limits For Autorotation

Answer 20

Maximum airspeed for autorotation is 145 KTAS. Above 145 KTAS, drag on the rotor system will cause NR to decay rapidly.

Question 21

Airspeed Limits for Single Engine Operation

Answer 21

Maximum airspeed for single engine operation is the greater of:

1. 67% of VNE determined from Figure 5-13 using the GROSS WEIGHT line. If above this, a successful autorotation may not be possible due to rapid NR decay.
2. The airspeed for minimum power determined from the applicable Chapter 7 cruise charts using the MAX END/MAX R/C lines.

Question 22

Maximum Airspeeds During Manual Stabilator Operations

Answer 22

Maximum airspeeds are based on stabilator position. The stabilator position and nominal airspeed restrictions are displayed on the FLT, FLT SET and SYS pages, as described in Paragraph 2-45d.

Question 23

Maximum Rearward and Sideward Airspeed

Answer 23

Maximum rearward and sideward airspeed is 45 KTAS for all gross weights due to the possibility of loss of tail rotor effectiveness.

Question 24

Maximum Airspeed for Searchlight Extension

Answer 24

The searchlight is designed for operation (extend/retract/rotate) at airspeeds up to 90 knots. However, if movement operation is not attempted, the lighthead can be left in any extended position at speeds up to VNE.

Question 25

Maximum Airspeed for Stores Jettison

Answer 25

Jettison of external armament stores is not authorized except for emergency situations and then only from unaccelerated flight during:

1. Maximum airspeed for stores jettison is 130 KTAS
2. Hover to 45 KTAS (minimize side slip, if possible)
3. 45 to 130 KTAS (ball centered, if possible)

Question 26

Maneuvering Limitations

Answer 26

For normal load factors, refer to Figure 5-14. Intentional maneuvers beyond attitudes ±30° in pitch or ±60° in roll are prohibited.

Question 27

Excessive Tail Rotor Scissors Loads

Answer 27

Avoid aggressive directional and lateral control inputs greater than 1 inch/second when conducting combat maneuvers requiring a left turn. This is to prevent excessive tail rotor scissors loads.

Question 28

Excessive Tail Rotor Loads

Answer 28

Avoid large pedal step inputs in arresting right hovering/low speed yawing turns greater than 60°/second. This is to prevent excessive tail rotor drive system loads.

Question 29

Flight with Canopy Enclosure Open

Answer 29

Flight with the canopy open is prohibited, except for smoke/fume elimination.

Question 30

Landing Limits

Answer 30

Do not complete a landing on terrain which produces a pitch attitude change from a hover greater than 7° nose up or 12° nose down; or a roll attitude greater than 10°. Data is not available beyond these limits at gross weights above 17,650.

Question 31

Flight into Turbulence

Answer 31

Flight into known or forecast extreme turbulence or into known severe turbulence is prohibited.

Question 32

Flight In Icing Conditions

Answer 32

Intentional flight into moderate icing conditions is prohibited. Flight into known or forecast trace or light icing conditions is ​authorized and not considered a hazard unless the condition is encountered for an extended period (over one hour).

Question 33

Flight In Instrument Meteorological Conditions

Answer 33

The aircraft is qualified for IMC flight.

Question 34

Rotor Limitations - Start and Stop Limits

Answer 34

Maximum wind velocity for rotor start or stop is 45 knots to prevent droop stop damage.

Question 35

Use of Force Trim

Answer 35

Force trim will not be turned off except in a failed or partial failed mode.