Lockheed YC-121F Turbo Constellation

 

 

 

 

 

 

 

V-SPEEDS:

 

 

Vmca = 112 KCAS

 

 

 

 

ENGINE OPERATION NOTES.

 

 

Throttles:

 

Engine power is controlled by a single lever, the throttle, which coordinates fuel flow with propeller governor setting (propeller RPM).

 

Reverse thrust is available by a mouse click on reverse lights or by pressing the "F2" key. In VC, reverse power can be controlled by the reverse levers attached to throttle levers. To cancel reverse power, you can press the “F1” key, click again on reverse lights or advance throttle in the positive range.

 

The throttle quadrant has three basic positions: Ground Idle, Flight Idle and Take Off. In the Flight Idle position there is a detent to avoid going below this position in flight. The Flight Idle power is adjusted to give zero thrust at 85 KIAS.

 

In FS9 there is no possibility to simulate the Flight Idle detent, so the throttle idle position yields Flight Idle when airborne and Ground Idle on ground. On ground, the throttle range from 0% to 6% is equivalent to the range from Ground Idle to Flight Idle in the real airplane.

 

 

Propellers:

 

The engines are equipped with full-feathering, reversible pitch propellers, incorporating synchronized or constant speed governor control. The normal RPM range is from 91% to 100%. In Ground Idle, RPM is 71-75%.

 

The governor controls the engine RPM according to throttle position, in the range from 91% to 100% RPM.

 

Propeller Synchronizer:

 

Provision for synchronisation the four propellers through a limited band (2%) of RPM is provided for by an electronic controller. Either engine #2 or engine #3 may be selected as master engine. A two positions synchronizer switch is located in the FE panel, placarded ENG 2, OFF and ENG 3. The synchronizer is operating only if propeller condition lever is in the RUN position.

 

 

Propeller condition levers:

 

Four propeller condition levers are located in FE panel. The levers have three positions: FEATHER, UNFEATHER, and RUN.

 

Fuel Shut-Off Levers:

 

Four fuel shut-off levers are located in FE panel. The levers have two positions: OFF and OPEN.

 

Negative Torque Control:

 

A Negative Torque Control (NTC) is installed in each engine to automatically provide an increased pitch (decrease RPM) whenever a condition of negative torque (propeller driving the turbine) exists, to reduce the windmilling propeller drag. When a negative torque is detected, the pitch is increased to reduce RPM to about 60%. The system is armed when airspeed is below 270 KTAS.

 

If engine power is restored prior to feathering, normal propeller operation is restored automatically.

 

 

Fuel pumps:

 

Electric auxiliary fuel pumps are installed in each tank, supplying fuel to main fuel manifold. To avoid cavitations in engine driven main fuel pumps, the auxiliary pumps of tanks in use should be switched on as long as the engine runs. Four low fuel pressure warning lights are installed in FE panel, illuminating if there is not enough pressure to feed the engine fuel pumps safely.

 

 

PERFORMANCES SUMMARY (from USAF Flight Manual):

 

RATE OF CLIMB.

 

 

 

 

 

 

 

 

 

When holding at low weights, it is recommended not to reduce power below 30% of Normal Rated Power (about 10 psi TP at S.L.), allowing speed at low altitudes to be higher that indicated in the table above for weights below 110,000 lb.