Engine Limitations (4.5)

Question 1

Define TRT

Answer 1

The highest value of thrust the engine will deliver. This rating is restricted to 5 minutes of operation. “Go-Around” thrust is similar to this just for in flight.

Question 2

Define MCT

Answer 2

The maximum thrust approved for continuous use.

Question 3

Oil Consumption Limits
(Maintenance vs precautionary shutdown of engine)

Answer 3

1/8 gph: Maintenance required after flight
1/2 gph: during stabilized engine operation for an extended period (3-4 hours), shutdown the engine unless needed for safety of flight.

Question 4

N1 Limitations
(Starting, Ground Idle, TRT, MCT, Flight Idle)

Answer 4

Starting: Positive rotation
Grnd Idle: 16-22%
TRT: 102%
MCT: 102%
Flight Idle: Variable (normal range: 22-102%)

Question 5

N2 Limitation
(Normal, Max, Ground Idle, Min inflight)

Answer 5

Normal: 60-105%
Max: 105%
Ground Idle: 54-61%
Min Inflight: 69%

Question 6

Max EGT Limits
(Starting, Ground Idle, TRT, MCT, Flight idle, Caution, Excursion range, Precautionary shutdown)

Answer 6

Starting: 725 C
Grnd Idle: 675 C
TRT: 930 C
MCT: 895 C
Flight Idle: 895 C
Caution: 895-930 C
Excursion (1.5 minutes): 930-940 C
Precautionary Shutdown: 950 C

Question 7

Oil Pressure
(Starting, Ground Idle, TRT, MCT, Flight idle, Continuous ops, Min, Max)

Answer 7

Starting: positive
Ground Idle: 11-35 psi
TRT: 35-90
MCT: 35-90
FLT Idle: 20-60
Cont ops: 11-90
Min: 11
Max: 90

Question 8

Oil Temperatures
(Starting/Ground Idle, TRT/MCT/Flt idle, Max, 15 minute limit range)

Answer 8

Starting/Ground Idle: -50 to 140 C
TRT/MCT/Flt Idle: 5 to 140 C
Max: 155 C
15 Minute: 140 to 155 C

Question 9

Wind Limitations for Starting

Answer 9

Tailwind: 20+ knots requires thrust reverser deployed start
Crosswind: 30 kts