MH-60R - Limits Flashcards
(75 cards)
What are engines limited by?
They are limited by Ng, Np, TGT, oil pressure, and oil temperature.
What to do after an operational limit is exceeded.
An appropriate entry shall be made on a MAF. The entry shall state what limit(s) we’re 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.
TGT for aircraft with Intermediate Rated Power (IRP) limited DECUs.
0-810 C Continuous Green >810-851 C 30 Minutes Yellow >851-903 C 2.5 Minutes Red >903-949 C 12 Seconds Red 949 C Maximum Red
TGT for aircraft with Maximum Rated Power (MRP) limited EDECUs.
0-810 C Continuous Green >810-851 C 30 Minutes Yellow >851-878 C 10 Minutes* Yellow >878-903 C 2.5 Minutes Red >903-949 C 12 Seconds Red 949 C Maximum Red
*As required for Max power and limiter check only
Power Turbine Speed (Np)
<96% Avoid Red
96-105% Continuous Green
105-120% 12 Seconds Yellow
120% Maximum Red
NOTE:
During engagement, extended operations in the 20-40% and 60-75% ranges may cause engine damage.
Main Rotor Speed (Nr)
<96% Avoid Red 96-101% Continuous Green 101-120% Precautionary Yellow 120% Maximum Red >120% 123%* Red 127, 137, Overspeed Red and 142% latch
*Maximum for FCF only
Dual Engine Torque(TRQ) <80 KIAS
0-120% Continuous Green
120-144% 10 Seconds Yellow
144% Maximum Red
Dual Engine Torque(TRQ) >80 KIAS
0-106% Continuous Green
106-127% 10 Seconds Yellow
127% Maximum Red
Single Engine Torque(TRQ)
0-135% Continuous Green
135-144% 10 Seconds Red
144% Maximum Red
Gas Generator Speed (Ng)
0-98% Continuous Green
98-102.2% Continuous Yellow (Red above 102%)
>102.2-105.1% 12 Seconds Red
105% Maximum Red
Transmission Temperature (XMSN T)
-50-105 C Continuous Green
105-120 C Precautionary Yellow
120 C Maximum Red
Transmission Pressure (XMSN P)
20 psi Minimum Red
20-30 psi Idle and Transient Yellow
30-65 psi* Continuous Green
65-130 psi Precautionary Yellow
130 psi Maximum Red
*45-60 psi in level flight
Engine Oil Temperature (ENG OIL T)
-50-135 C Continuous Green
135-150 C 30 Minutes Yellow
150 C Maximum Red
Engine Oil Pressure (ENG OIL P)
22 psi Minimum Red
22-26 psi Precautionary Yellow*
26-100 psi Continuous Green
100-120 psi Precautionary Yellow
120 psi Maximum Red
*Green when Ng <70%
NOTE:
Normal idle range is 22 to 55 psi.
Engine start (OAT <16 C)
First Cycle 60 seconds
Second Cycle 60 seconds
Third Cycle 60 seconds
Fourth Cycle 30 minutes
NOTES:
1. A start cycle is defined as starter initiation, acceleration, and dropout.
- Times for motoring are cumulative within a 5 minute period.
Engine start (OAT 16-52 C)
First Cycle 60 seconds
Second Cycle 30 minutes
Crossbleed start limitations
May be attempted with the operating engine at or above 94% Ng and rotor speed at 100% Nr.
When are engine starts prohibited?
With the main rotor blades and/or tail rotor pylon folded.
Engine idle limitations with the gust lock engaged
Engine operation with the gust lock engaged is prohibited.
Minimum planned fuel on landing
No less than 600 pounds.
APU Limitations
The APU is not intended for in-flight use. Operation 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 during 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. If transmission oil pressure and/or temperature are in the precautionary range, the helicopter shall not be scheduled for additional flights until maintenance action is performed.
NOTE:
Prolonged hovering in hot weather (94F or 35C) and high gross weight may cause temperatures to rise in to the yellow precautionary range. Operation in the precautionary range for less than 30 minutes during any one flight under these conditions is acceptable.
Transmission Oil Pressure Limitations (level flight)
During steady-state level pitch attitudes, 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. Maintenance action shall be performed to prevent potential long-term damage to the gearbox.
- Steady pressure outside of 45-60 psi, but within the normal limits of 30-65 psi.
- Fluctuations not to exceed a range of 10 psi, within the normal limits of 30-65 psi.
Transmission Oil Pressure Limitations (autorotations, downwind hover, rearward flight, slope-up landings, etc.)
Fluctuations (including momentary fluctuations below 30 psi and transient drops below 20 psi for up to 1 second) are acceptable. Operating with pressure fluctuations below 30 psi shall be limited to 30 minutes.
