Chapter 5 - Limitations Flashcards
Rotor Speed NR (%)
110 - Maximum (>110 red)
105-110 - Transient (yellow)
105 - High Rotor Warning Annunciated
94-104 - Normal (green)
0-93 - Transient (red)
Engine Oil Pressure
and
NOTE
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.
Hydraulic Pressure (PSI)
>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)
Engine Starter Limitations
(Explanation)
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.
Engine Starts At Ambient Temperatures of 61° F (16° C) and Below
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.
Engine Starts At Ambient Temperatures Above 61° F (16° C)
Two consecutive start cycles may be made. A 30 minute rest period is then required before any additional starts.
Dual Engine Starts
Dual engine starts are prohibited due to insufficient IPAS air.
Engine Temperature Limitation TGT (°C) With SE Picture
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)
Engine Temperature Limitation TGT (°C)
NOTE
With DE Verticle Tape Picture
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
Engine Power Turbine Speed NP (%)
and
NOTE
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%.
Engine Gas Generator NG
- 0 - Maximum (>106.0 red)
- 1-106.0 - Transient 12 sec (yellow)
- 1-105.0 - Normal (green)
- 0 - Minimum engine out warning annunciated (<63.0 red w/ box)
Engine Torque TQ (%) With NR <50%
30 - Maximum (>30 red)
0-30 - Normal (green)
Engine Torque TQ (%) With NR <90%
70 - Maximum (>70 red)
0-70 - Normal (green)
Engine Torque TQ (%) DE
115 - Maximum (>115 red)
101 - 115 (Transient 6 sec (yellow)
0-100 - Normal (green)
Engine Torque TQ (%) SE
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)
Auxillary Power Unit (APU)
CAUTION
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.
APU Operating Limitations
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.
Extended APU Ground Operations
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.
Weight Limitations
The aircraft maximum gross weight is 20,260 pounds, except for non-tactical ferry flights, which may not exceed 23,000 pounds.
Airspeed Limits For Autorotation
Maximum airspeed for autorotation is 145 KTAS. Above 145 KTAS, drag on the rotor system will cause NR to decay rapidly.
Airspeed Limits for Single Engine Operation
Maximum airspeed for single engine operation is the greater of:
- 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.
- The airspeed for minimum power determined from the applicable Chapter 7 cruise charts using the MAX END/MAX R/C lines.
Maximum Airspeeds During Manual Stabilator Operations
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.
Maximum Rearward and Sideward Airspeed
Maximum rearward and sideward airspeed is 45 KTAS for all gross weights due to the possibility of loss of tail rotor effectiveness.
Maximum Airspeed for Searchlight Extension
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.
Maximum Airspeed for Stores Jettison
Jettison of external armament stores is not authorized except for emergency situations and then only from unaccelerated flight during:
- Maximum airspeed for stores jettison is 130 KTAS
- Hover to 45 KTAS (minimize side slip, if possible)
- 45 to 130 KTAS (ball centered, if possible)
Maneuvering Limitations
For normal load factors, refer to Figure 5-14. Intentional maneuvers beyond attitudes ±30° in pitch or ±60° in roll are prohibited.
Excessive Tail Rotor Scissors Loads
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.
Excessive Tail Rotor Loads
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.
Flight with Canopy Enclosure Open
Flight with the canopy open is prohibited, except for smoke/fume elimination.
Landing Limits
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.
Flight into Turbulence
Flight into known or forecast extreme turbulence or into known severe turbulence is prohibited.
Flight In Icing Conditions
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).
Flight In Instrument Meteorological Conditions
The aircraft is qualified for IMC flight.
Rotor Limitations - Start and Stop Limits
Maximum wind velocity for rotor start or stop is 45 knots to prevent droop stop damage.
Use of Force Trim
Force trim will not be turned off except in a failed or partial failed mode.
