TH67 Operating Limitations And Restrictions Flashcards
Engine oil temperature
0 to 107°C continuous operation
107°C maximum
Engine anti-ice limitations
Engine anti-ice shall not be used in ambient temperatures above 4 deg C.
Engine anti-icing shall be ON for flight in visible moisture in temperature 4 deg C or below.
Low inlet pressure caution
Caution:
Takeoff with LOW INLET PRESSURE caution light illuminated is PROHIBITED.
Engine starter limits
If there is no rise in TOT within the first 20 seconds of engaging the starter, limit starter energizing time to the following:
-External power: 25 seconds ON, 30 seconds OFF, 25 seconds ON, 30 seconds OFF, 25 seconds ON, 30 minutes OFF
-Battery: 40 seconds ON, 60 seconds OFF, 40 seconds ON, 60 seconds OFF, 40 seconds ON, 30 minutes OFF
If there is no rise in TOT within the first 20 seconds of energizing starter, limit starter energizing time to the following:
-External / Battery power: 1 minute ON, 1 minute OFF, 1 minute ON, 1 minute OFF, 1 minute ON, 30 minutes OFF
Engine starting limitations
During starting if N1 does not reach 58% in a total time of 45 seconds (or 60 seconds below 10 deg C FAT), close throttle and press starter button until TOT is below 200 deg C. If engine fails to start on third attempt, abort start and make an entry on DA form 2408-13-1. Starter engage time limits above do not apply to engine starting limitations should abort start procedures become necessary.
Fuel limitations
Type B or JP-4 may be used at all ambient temperatures with no restrictions.
Type A or A-1, JP-5 and JP-8 may be used in ambient temperatures above -32 deg C. The minimum fuel pressure is 8 PSI at temperatures of -18 deg C to -32 deg C. At temperatures above -18 deg C the minimum fuel pressure is 4 PSI.
If fuels other than Type B or JP-4 are used, a deceleration check must be performed prior to the first flight of each day. A deceleration check must also be performed prior to each flight if Power Off maneuvers are to be performed.
The use of AVGAS in the TH-67 is prohibited.
Health indicator test (HIT)
Select an N1 speed based on free air temperature. TOT is compared to a predetermined value (baseline).
If the difference between recorded and baseline TOT is:
+/-20 deg C or greater, an entry in DA form 2408-13-1 will be made
+/-40 deg C or greater is cause for grounding the aircraft
Longitudinal center of gravity limits
VMC center of gravity limits are from station 106 to 114.2; forward and aft limits are variable depending on gross weight and configuration.
2425 pounds and below 106.0 - 114.2
At 3200 pounds 106.0 - 111.6
At 3350 pounds 106.9 - 110.8
Lateral center of gravity limits
3 inches left of centerline
4 inches right of centerline
Weight limitations
Maximum allowable ramp weight is 3,350 lbs
Maximum allowable gross weight for hover/flight is 3,350 lbs
Minimum front seat weight is 170 lbs
Flight restriction for high power
VNE 80 knots with >85% to 100% torque applied
Aerobatic maneuvers
Aerobatic maneuvers are prohibited. Aerobatic flight is defined to be any intentional maneuver involving an abrupt change in aircraft attitude, an abnormal attitude, pitch angle greater than 30 deg or roll angles greater than 60 deg, or abnormal acceleration not necessary for normal flight.
Control movements
Abrupt control movements, including rapid and repetitive anti-torque pedals reversals are prohibited to avoid excessive stresses in the structure. This restriction in no way limits normal control application.
Caution:
For gross weights greater than 3000 lbs and density altitudes greater than sea level, the directional control margin may be significantly reduced while hovering in winds from the right greater than 20 knots or for right sideward flight at speeds greater than 20 knots.
Engine oil pressure
50 psi minimum below 78% N1
90 psi minimum from 78% to 94% N1
115 psi minimum above 94% N1. Double wide arc.
50 psi minimum
130 psi maximum
Note: During cold temperature operation the oil pressure may exceed the maximum of 130 PSI. Stabilize the engine at idle speed of 60 to 64% until the engine oil temperature is above 0°C and the engine oil pressure is within normal limits.
Transmission oil pressure
30 to 50 PSI continuous operation
30 psi minimum
70 psi maximum
Transmission oil temperature
15°C to 110°C continuous operation
110°C maximum
Loadmeter
70% maximum
Fuel pressure
4 psi minimum
4 to 30 PSI continuous operation
30 psi maximum
8 psi minimum: Type A, A-1, JP-5, JP-8 fuel below -18°C to -32°C.
Airspeed indicator
Note: autorotation above 100 knots indicated airspeed will result in high rates of descent and low rotor RPM.
0 to 130 knots continuous operation
130 knots maximum
100 knots maximum for autorotation
VNE for internal gross weight above 3,200 pounds is 78 knots indicated airspeed, not to exceed placarded VNE.
Turbine outlet temperature
Note: the red warning light illuminates when either of the following conditions are exceeded: 810 to 927°C for 10 seconds, or higher than 927°C.
100 to 738°C continuous operation
738 to 810°C take off power range (5 minute limit)
810°C maximum
810 to 843°C, 6 second transient (Not to be used intentionally)
927°C maximum during starting and shutdown (10 seconds maximum)
Gas producer (N1)
60 to 105% continuous operation
105% maximum
105 to 106% transient (15 seconds maximum)
Rotor indicator
90% minimum operation 50 to 60% accelerate through this range 90 to 107% normal operation 107% maximum Power on transient rotor droop limit is 95% (five seconds maximum)
Power turbine indicator (N2)
97% minimum operation
97 to 100% continuous operation
100% maximum
N2 75 to 88%, 60 seconds maximum (time not cumulative)
VMC airspeed limitations
At 3000 pounds gross weight and below:
VMC VNE 130 KIAS sea level to 3000 ft density altitude. Decrease VNE 3.5 KIAS per 1000 feet above 3000 feet density altitude. Maximum density altitude 20,000 feet.
Above 3000 pounds gross weight:
VMC VNE 122 knots sea level to 3000 ft density altitude. Decrease VNE 7 KIAS per 1000 ft above 3000 ft density altitude. Maximum density altitude 13,500 feet.
VNE for internal gross weight above 3200 lbs is 78 KIAS, not to exceed placarded VNE.
