Limits Flashcards
(45 cards)
Engines are limited by…
Ng, Np, TGT, oil pressure, oil temperature
Anytime an operational limit is exceeded…
An appropriate entry shall be made on a MAF. The entry shall state what limit(s) were exceeded and include range, duration, and any additional data that would aid maintenance personnel.
Note: If a limit is exceeded to the extent that a red “XXX” is indicated, the crew shall land as soon as practicable.
Start cycle definition
Starter initiation, acceleration in Ng, and starter dropout/disengagement. A 60-second delay between start attempts is required any time a start is aborted, except during emergencies.
Crossbleed starts
May be attempted with the operating engine at or above 94% Ng and rotor speed at 100% Nr. Engine starts with the main rotor blades and/or tail rotor pylon folded are prohibited.
Caution: Donor of Ng less than 94 percent may result in hot starts.
DECU TGT Limits (IRP)
0-810: continuous: green
>810-851: 30 mins: yellow
>851-903: 2.5 mins: Red
>903-949: 12 secs: Red
EDECU TGT Limits (MRP)
0-810: continuous: green >810-851: 30 mins: yellow >851-878: 10 mins: yellow >878-903: 2.5 mins: Red >903-949: 12 secs: Red 949: Max: Red
Np Limits
> 96%: Avoid: Red
96-101%: Cont: Green
101-120%:12 sec:Yellow
120%: Max: Red
Caution: Operating engine steady state between 20 to 40% Np or 60 to 75% Np may cause engine damage.
Nr limits
<96%: Avoid: Red 96-101%: Cont: Green 101-120%: P: Yellow 120%: Max: Red 127, 137, 142: OL: Red
Dual-Engine Q <80 KIAS
0-120%: Cont: Green
120-144%:10 s: Yellow
144%: Max: Red
Dual-Engine Q >80 KIAS
0-106%: Cont: Green
106-127%%:10 s: Yellow
127%: Max: Red
Single-Engine Q
0-135%: Cont: Green
135-144%:10 s: Yellow
144%: Max: Red
Ng Limits
0-98%: Cont: Green
98-102%: Cont: Yellow
102-105%:12 sec: Red
105%: Max: Red
XMSN Temperature
-50-105: Cont: Green
105-120: P :Yellow
120: Max : Red
XMSN Pressure
<20: Min: Red 20-30: Idle and transient: Yellow 30-65 (45-60 in lvl flt): Cont: Green 65-130: P: Yellow 130: Max: Red
Engine Oil Temp
-50-135: Cont: Green
135-150: 30 mins: Yellow
150: Max: Red
Engine Oil Pressure
22: Min: Red 22-26: P: Yellow 26-100: Cont: Green 100-120: P: Yellow 120: Max: Red Note: Normal idle range is 22 to 55 psi.
Engine Starter Limits
Engine Start:
<16: 60-60-60-30 mins
16-52: 60-30 mins
Engine Motoring:
Any temp: 2 mins-5mins-2 mins-30 mins
Engine operation with…
the gust lock engaged is prohibited
Minimum Planned Fuel on Landing
Shall be no less than 225 lbs (approximately 20 mins) of fuel per main tank. With fuel less than 300 lbs per main tank, maintain balanced flight at AOBs greater than 30 degrees.
APU Limits
The APU is not intended for routine in-flight use. Operation of the APU in flight shall be limited to essential operations only. Acceptable in-flight use includes EPs, single engine training, practice autorotations, and powering the ECS during extreme temperature operations.
Transmission is limited by:
Nr, torque, oil pressure, and oil temperature
Note: Prolonged hovering in hot weather 95 degrees and high gross weight may cause temperatures to rise in the yellow precautionary range. Operations in the precautionary range for less than 30 mins durning any one flight under these conditions is acceptable.
Transmission Oil Pressure Limitations
During steady-state level pitch attitudes xmsn pressure should be between 45-60.
The following conditions do not constitute an immediate emergency situation, but may be indicative of a degraded lubrication system. Maintenance action shall be performed to prevent potential long-term damage to the gear box:
- Steady state pressure outside of 45-60 but w/in normal 30-65.
- Flux not to exceed a range of 10 psi within normal 30-65.
During transient pitch or steady-state nose-high pitch attitudes xmsn oil press flux (including momentary flux below 30 psi and transient drops below 20 psi for up to 1 sec) are acceptable. Press flux below 30 psi shall be limited to 30 mins
Max Wind Velocity for rotor engagement or disengagement
45 kts from any direction
Airspeeds
Auto: 100 KIAS Sideward/Rearward flight: 45 KIAS (35 with an external load) Two sas inop in IMC- 125 KIAS SAS/Boost Off- 140 KIAS Either PRI SERVO PRESS caution- 125 KIAS Cabin doors open- 120 KIAS Cabin doors open/closing- 100 KIAS Gunner windows opening/closing- 170 KIAS Landing light in transition- 130 KIAS Searchlight in transition- 100 KIAS Aircraft gross weight >22,000 lbs with an external load- 120 KIAS