Limits Flashcards
Exceeding Operational Limits
Anytime an operational limit is exceeded, an appropriate entry shall be made on an MAF. The entry shall state what limits were exceeded and include range, duration, and any additional data that would aid maintenance personnel.
The flight display’s digital readout will display “XXX” in red when a TGT or torque limit is exceeded.
If a limit is exceeded to the extent that a red “XXX” is indicated, the crew shall land as soon as practicable.
Engine Limitations
The engines are limited by Ng, Np, TGT, oil pressure and oil temperature. Specified temperature limits ensure that engines are operated at internal temperatures that will not shorten the service life expectancy of engine components.
Engine Starter Limitations, Starter Cycle
Engine starter limits are presented in Figure 4-2. A start cycle is defined as starter initiation, acceleration of the output drive, and starter dropout. A 60-second delay between start attempts is required any time a start is aborted, except during emergencies.
Engine Start Limitations
The single and dual engine start envelopes are presented in the Figure 4-3. For crossbleed starts, the receiving engine shall be at or above 24% Ng prior to advancing the PCL to IDLE.
Engine starts with the main rotor blades or tail pylon folded is prohibited.
The start TGT limit is 851C until idle speed is attained.
Engine Idle Limitations with Gust Lock Engaged
Engine operation with gust lock engaged is prohibited.
TGT
0-810 Continuous Green 810-851 30 mins Yellow 851-878 10 mins Red 878-903 2.5 mins Red 903-949 12 seconds Red 949 Maximum Red
Power Turbine Speed
<96 Avoid Red 96 to 105% Continuous Green (Yellow above 101%) 105 to 117% 20 Seconds Yellow 117 to 120% 12 Seconds Yellow 120% Max Red
During engagement, extended operations in the 20 to 40% and 60 to 75% ranges may cause engine damage.
Main Rotor Speed
<96% Avoid Red 96 to 101% Continuous Green 101 to 120% Precautionary Yellow 120% Max Red >120, 123% max FCF only Red 127% Overspeed Latch Red
Dual Engine Torque <80 KIAS
0 to 120% Continuous Green
120 to 144% 10 Seconds Yellow
144% Max Red
Dual Engine Torque >80 KIAS
0 to 106% Continuous Green
106 to 127% 10 Seconds Yellow
127 Max Red
Dual engine torque limits apply when both engines are above 65% torque
Single Engine Torque Limits
0 to 135% Continuous Green
135 to 144% 10 Seconds Red
144% Max Red
Gas Generator Speed
0 to 102.2% Continuous Green
>102.2 to 106% 2.5 mins Yellow
>106 to 107% 12 Seconds Red
107% Max Red
Transmission Temperature
-50 to 105C Continuous Green
105 to 120C Precautionary Yellow
120C Max Red
Transmission Pressure
20 psi Minimum Red 20 to 30 psi Idle and Transient Yellow 30 to 65 psi (45 to 60 psi in level flight) Continuous Green 65 to 130 psi Precautionary Yellow 130 psi Max Red
Engine Oil Temp
-50 to 135C Continuous Green
135 to 150C 30 Mins Yellow
150C Max Red
Engine Oil Pressure
22 psi Minimum Red 22 to 26 psi Precautionary Yellow 26 to 100 psi Continuous Green 100 to 120 psi Precautionary Yellow 120 psi Max Red
Normal idle range is 22 to 55 psi
Minimum Planned Fuel on Landing
Minimum planned fuel on landing shall be no less than 600 lbs.
APU Limitations
The APU is not intended for routine in-flight use. Operations of the APU in flight shall be limited to essential operations only. Acceptable in-flight use includes emergency procedures, single engine training, practice autorotations, and powering the ECS in extreme temperature operations.
Transmission Limitations
The transmission is limited by Nr, torque, oil pressure, and oil temperature. Operation is governed by whichever limit is reached first.
Engine torques over 150% are displayed as red XXX.
Transmission Oil Temperature Limitations
During any operating condition, no maintenance action is required if main transmission oil temperature is in the precautionary range continuously for 5 mins or less.
Prolonged hovering in hot weather, 86F (30C), may cause main transmission oil temperature to rise into the precautionary range. Operation in the precautionary range for less than 30 mins during any one flight under this condition is acceptable and no maintenance action is required.
Transmission Oil Pressure Limitations
During steady state level pitch attitudes (i.e., level flight), the transmission oil pressure should be 45 to 60 psi. The following conditions do not constitute an immediate emergency situation, but may be indicative of a degraded lubrication system. Any discrepancy shall be documented on a MAF.
1) Steady pressure outside of 45 to 60 psi, but within the normal limits of 30 to 65 psi.
2) Fluctuations not to exceed a range of 10 psi, within the normal limits of 30 to 65 psi.
During transient pitch or steady state nose high pitch attitudes (autorotations, downwind hovering, rearward flight, slope up landings, etc.) transmission oil pressure fluctuations (including momentary fluctuations below 30 psi and transient drops below 20 psi for up to one second) are acceptable. Operating with pressure fluctuations below 30 psi shall be limited to 30 mins.
During rotor engagement, a zero oil pressure indication may indicate a no-oil-flow condition through the oil lubrication system. Operating with a no oil pressure indication shall be limited to les than 1 minute and shall be documented on a MAF.
Rotor Engagement and Disengagement Limitations
Maximum wind velocity for rotor engagement or disengagement is 45 knots from any direction.
Airspeed Operating Limits
Vne: 180 KIAS
Sideward/Rearward Flight: 35 knots
Autorotation: 100 KIAS
Boost Off: 140 KIAS
SAS 1 and SAS 2 inoperative in IMC: 125 KIAS
Either PRI SERVO PRESS caution: 125 KIAS
Searchlight in fixed position other than stowed: 160 KIAS
Searchlight in transition: 100 KIAS
Dome at or above trail (cable extended 10 feet, dome approx 6 ft below aircraft): 70 KIAS, 45 deg AOB
Dome below trail: 70 KIAS, 15 deg AOB
Cabin door opening/closing: 60 KIAS
With cabin door open, uncoordinated flight should be avoided
With MTS installed, failure to maintain balanced flight below 90 KIAS in descents over 1000 FPM will result in inaccurate and erratic airspeed indications.
Maneuvering Limitations
Rate of descent is limited to 1000 fpm for rescue hoist loads.
External load and rescue hoist load maneuvering limitations:
35 KIAS, 10 deg AOB crosswind and side flight
120 KIAS forward flight
0-40 KIAS: 10-20 deg AOB
40-90 KIAS: 20 deg AOB
90-100 KIAS: 20-10 deg AOB
100-120 KIAS: 10 deg AOB
Hovering Limitations:
Prolonged rearward flight and downwind hovering should be avoided to prevent accumulation of exhaust fumes in the helicopter and heat damage to the window on an open cabin door.
Hovering turns at a rate in excess of 30 deg per second
Dipping sonar operations at altitudes other than 70 feet.
CAUTION: Deviation of aircraft hover altitude from 70 feet while the transducer assembly is entering or exiting the water may result in damage to the dipping sonar equipment due to electrostatic discharge.
Do not tow the transducer in the water above 8 KGS with the array folded and 4 KGS with the array unfolded.
CAUTION: Exceeding 8 KGS with array folded or 4 KGS with array unfolded may cause TA cable separation.
NOTE: Towing is defined as the cable contacting the funnel. Aircraft ground speed may be greater than 8 KGS (folded) or 4 KGS (unfolded) provided the cable is not in contact with the funnel.
AOB Limitations
Bank angles shall be limited to the following:
Normal operations: 45 deg
Operations above 10,000 ft DA: 30 deg
Either PRI SERVO PRESS caution: 30 deg
Boost off flight: 30 deg
Altitude Limitation:
Max operating density altitude is 13,000 ft
Prohibited Maneuvers
The following maneuvers are prohibited:
Aerobatic flight
Practice full-autorotation landings
Intentional approaches into or inducement of retreating blade stall
Rotor Brake Operating Limitations
Max rotor speed for rotor brake application is 76% Nr. Routine stops shall be made between 30 and 50% Nr. Routine rotor brake stops should be limited to 180 psi to extend service life.
Blade, Pylon, and Stabilator Fold and Spread Limitations
Max wind velocity for blade fold and spread is 45 knots from any direction. Following a complete blade fold and spread cycle, allow a 10 minute cooling period before commencing another blade fold and spread evolution. A complete blade fold and spread cycle is defined as a full spread evolution followed immediately by a full fold evolution or vice versa.
Maximum wind velocity for tail pylon or stabilator fold/spread operations is 45 knots from any direction.
Vne
180 KIAS
Sideward/rearward flight
35 knots
Autorotation
100 KIAS
Boost off
140 KIAS
SAS 1 and SAS 2 inoperative in IMC
125 KIAS
Either PRI SERVO PRESS caution
125 KAIS
Searchlight in fixed position other than stowed
160 KIAS
Searchlight in transition
100 KIAS
Landing Limitations, Rate of Descent
Max rate of descent for level terrain shall not exceed 720 fpm for gross weight less than 19,500 pounds and 480 fpm for gross weight above 19,500 pounds.
Max rate of descent for sloped terrain shall not exceed 360 fpm.
Landing limits, Touchdown Speed
Max touchdown speed shall not exceed 75 KGS with tail wheel locked and 20 KGS with tail wheel unlocked.
Landing Limits, Taxi Speed
Max ground taxi speed is 40 KGS. If the shimmy damper is not installed or inoperative, max ground taxi speed is 20 KGS.
Slope landing limitations
9 nose up slope
12 cross slope
6 nose down slope
A low frequency oscillation may occur when landing nose down one a slope with the cyclic near the aft stop.
Landing, wind direction
Downwind landings should be avoided.
Limits, windows
Windows shall not be installed or removed in flight, except during actual aircraft emergencies.
Aircraft Operating Gross Weight Limitations
The maximum operating gross weight is 23,500 pounds. The maximum launch and recovery gross weight for aviation ships is 23,500 pounds. The maximum launch and recovery gross weight for air capable ships and amphibious assault aviation ships is 22,500 pounds.
Internal Load Weight Limitations
The max cargo floor loading is 300 pounds per square foot.
External Load Weight Limitations
The max weight that may be suspended from the cargo hook is 6,000 pounds. The max weight that may be suspended from the rescue hoist is 600 pounds.
Center of Gravity Limitations
Longitudinal CG limits are presented in figure 4-5. At max gross weight, the lateral cg limits are 8.0 inches right and 7.5 inches left.
Minimum Aircraft Equipment for Night Flight Over Water
- LAWS
2. Altitude hold (RAD ALT or BAR ALT)
Minimum Aircraft Equipment for Flights into Forecast or Known Icing Conditions
Helicopters equipped with operable anti-ice and blade de-ice equipment are permitted flight into forecast or known trace or light icing conditions. All installed anti-ice/de-ice equipment (windshield, engine, rotor) shall be operational prior to flight. Helicopters not equipped with operable blade de-ice equipment are prohibited form flight into forecast or known icing conditions (ambient temperatures of 5C or below in visible moisture). Refer to Ch14.
The following icing limitations apply:
- Flight into known icing conditions without de-ice equipment is prohibited.
- Flight into forecasted or known moderate or severe icing conditions is prohibited.
Minimum Equipment for Passengers
Except in emergency situations, helicopter emergency egress light in systems (ADHEELS and IHEELS) shall be operational for all overwater flights requiring passengers/non-aircrew in the cabin.
For passenger and aircrew seating requirements, refer to CNAF M-3710.7 Ch7.
Temperature Limits
Operations at temps below -40C (-40F) or above 60C (140F) are prohibited.
Backup Hydraulic Pump Limitations
During prolonged ground operation of the backup pump with the rotor system static, the backup pump is limited to the operating times shown below to prevent hydraulic fluid from overheating.
OAT 33 to 38 C: 24 mins operating time, 72 mins cool down time
OAT 39 to 60 C: 16 mins operating time, 48 mins cool down time.
APU Operating Limits
To prevent APU overheating, APU operation at ambient temperature of 43C and above with engine and rotor operating is limited to 30 mins. With engine and rotor not operating, the APU may be operated continuously up to to an ambient temp of 51C.
