19 Power Plant

Question 1

Power plant model name

Answer 1

The Challenger 604 is equipped with two General Electric CF34-3B high-bypass ratio turbofan engines.

Question 2

Bypass / Core air thrust ratio

Answer 2

80% of the thrust at takeoff is produced by Bypass airflow.
20% of the thrust at takeoff is produced by Jetpipe thrust.
Air bypass is 1/6.5

Question 3

At what % N2 rpm does ignition and ATS (air turbine starter) disengage?

Answer 3

At 55% N2 rpm, the starter control valve closes and the air turbine starter disengages.

Question 4

Starter engagement limits

Answer 4

STARTER — COOLING
30 sec ——- no cooling
30 sec ——- no cooling
30 sec ——- 5 minutes (Same for subsequent attempts)

Question 5

Dry motoring engagements limits

Answer 5

DRY MOTORING — COOLING
90 sec —————– 5 minutes
30 sec —————– 5 minutes (Same for subsequent attempts)

*Dry-motoring is performed with ignition off and thrust levers at SHUTOFF.

Question 6

Continuous ignition must be used during the following flight conditions:

Answer 6

• T/O & LND on contaminated runways.
• T/O with high crosswind components > 10 knots.
• Flight in moderate or heavier intensity rain.
• Flight in moderate or heavier intensity turbulence.
• Flight in the vicinity of thunderstorms.

Question 7

When does N1 vibration turn amber?

Answer 7

2.7

When the N1 vibration level is 2.7 mils or greater, the color of the readout changes to amber. There is no associated caution EICAS message