TM  1-1520-240-10 2-3-2            The power turbine governor senses the increases and reduces the flow of fuel to the gas producer, thus de- creasing the engine output power. The power turbine speed governor allows the power tur- bine output speed to decrease (droop) approximately 10 percent when the power loading varies from minimum to full load. This is minimized by a droop eliminator linked to the thrust control rod. The droop eliminator automati- cally changes the power turbine lever to compensate for droop as pitch is increased or decreased. Another type of droop, which is only transient, occurs as a result of the time required for the engine to respond to changing loads due to system lag. 2-3-8.  ENG COND Levers  712 Two ENG COND (engine condition) levers, one for each engine are on the ENG COND panel (fig. 2-3-1) of the overhead switch panel. Each lever has three positions labeled STOP, GND, and FLT. They are used to select appropriate fuel flow rates for GND, FLT, and STOP (en- gine shutdown). Power is supplied by the DC essential buses  through  the  ENGINE  NO.  1  and  NO.  2  COND CONT circuit breakers on the No. 1 and No. 2 PDP. Each ENG COND lever is spring-loaded outboard and is inhibited by lock gates. They allow the pilot to proportion- ally control acceleration of the gas producer from STOP to FLT. Two engine control caution capsules are on the master caution panel (fig 2-14-5). They are labeled NO. 1 ENG N1 CONT and NO. 2 ENG N1 CONT. The cap- sules normally illuminate when the ENG COND levers or the N1 actuators are at an intermediate position between STOP,  GND,  or  FLT.  They  extinguish  when  the  ENG COND lever and N1 actuator positions agree. However, they  remain  illuminated  if  a  component  of  the  system (actuator, control box, or condition panel) has failed in other than a detent position. Power is supplied by the DC essential bus through the LIGHTING CAUTION PNL cir- cuit breaker on the No. 1 PDP. Figure  2-3-1.  Engine Condition Panel  712 CAUTION When  the  ENG  COND  lever  is  placed  to GND during start sequence, the N1 actua- tor   could   inadvertently   go   beyond   the ground position. The respective ENG N1 COND   caution   capsule   will   illuminate. However, ignition will still occur if the start switch is moved to START, thus resulting in a possible engine runaway. CAUTION When  adjusting  controls or switches on the  overhead  switch  panel,  make  sure gloves or sleeves do not catch and inad- vertently move the ENG COND levers. The ENG COND lever must be at GND before the engine will start. When an ENG COND lever is advanced from STOP to GND, power is then supplied to the electrome- chanical actuator which establishes an appropriate fuel flow rate at ground idle. The speed of the gas producer with the lever at GND should be 60 to 63 percent N1. When an ENG COND lever is moved to FLT, the engine is operating within the N2 governing range, unless the engine is “topped out” at which time it goes back to N1 governing. The N2 governor then takes control to main- tain selected rotor RPM (RRPM) in response to the en- gine  beep  trim switches and collective pitch changes, When an ENG COND lever is moved to STOP, the gas producer lever closes the fuel control fuel shutoff valve which stops fuel flow to the gas producer. Each electrical system is completely separate and a fail- ure in one system will not affect the other. A built-in me- chanical brake holds the actuator at its last selected posi- tion if loss of electrical power occurs. ENG COND lever friction is provided to reduce the possibility of overtorqu- ing the engine transmissions by resisting movement of the ENG COND levers. The ENG COND lever friction brake cannot be adjusted by the pilot and a force of 4 to 5 pounds is needed to move them. 2-3-9.  Normal Engine Beep Trim Switches. 712    On  712  engine  installations  engine  beep  trim switches are active at all times during normal operation. Two  momentary  switches  are  on  the  auxiliary  switch bracket of each THRUST CONT lever and are labeled ENGINE BEEP TRIM (fig. 2-5-1). Both switches have an RPM INCREASE, RPM DECREASE, and a neutral posi- tion.  712   One switch is labled NO. 1 & 2 which is normal- ly used to select desired RRPM. The second switch is labeled NO. 1 which will only affect the No. 1 engine and is used to match engine loads which are indicated by the dual torquemeters.