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Moose4

Captain Sim C-130 condition levers and cruise/climb settings

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Hey all...I've been messing around with my Captain Sim C-130, and have a question about the condition levers. If I click the condition levers forward to "run" as the manual (and tutorials I've found) state, the prop RPM just goes to 100% once I put any throttle on it, and stays there, so there's no rotating prop animation. Is this the normal setting for the C-130, just to leave the prop RPM at 100% through all parts of a flight?Also, does anyone have any ideas about typical power settings (ITT, fuel flow, etc.) for climb and cruise? Thanks.Lewis "Moose" GregoryDurham, North Carolina

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Hello,Just for the record The C-130 has a constant speed propeller system. At Low speed ground Idle (LSGI) The prop Rpm is between 69 and 72 percent. At Normal Speed Ground Idle ( NSGI) The prop RPM is 98 to 102 percent and stays there for all flight and ground operations till the engineer puts the engines at LSGI just prior to engine shutdown.Some Technical Stuff:The prop turns at 1020 Rpm at the reduction gearbox shaft. The propshaft has a beta feedback gear that is splined to the number 1 prop blade. The other end of the beta feedback shaft is splined to the prop assembly valve housing that is mounted on top of the prop assembly pump housing. The pump housing contains 2 hydralic pressure pumps, one electrical standby pump and one scavange pump. The hydralic fluid that is contained in the pump housing ( approx 26 quarts ) is used by the assembly to change prop blade angle by way of the valve housing. The valve housing uses a speeder spring and flyweight assembly that rotates according to prop RPM. The valve housing is also attached to the throttle system mechanically. When the pilot move the throttles below the flight idle gate range( Alpha Range), he is mechanically changing the prop Rpm directly as the turbine engine speed is increased. When the throttles are moved down over the flight idle gate( Beta Range ), the prop blade control is now being done by the speeder spring and flyweight assembly. As the pilot increases power for take-off, the speeder spring and flyweight assembly sense the prop RPM increase and adjust a porting valve to send more hydralic fluid to the prop to increase pitch thus maintaining 100 percent RPM. Now, I know what your asking yourself, How does the prop assembly know when the proper amount of pitch has been applied to keep the RPM at approx 100 percent?Well, You remember the beta feedback gear that is splined to the number 1 prop blade? It sends a mechancally geared signal to the speeder spring and flyweight assembly to center the fluid porting valve back to the zero effect position so that the blade will stop at the present postion.This process is very effective in allowing the Aircraft to tke full advantage of instant power adjustments to get instant power tansfer to the prop blades while maintainng 100 percent RPM.Simple Huh :0)Now, I know you would like to know about the Prop assembly pitchlock regulator, but that can be covered in a later thread.As far as engine power settings, for an Aircraft equipted with Allison T-56-15 engines, Max takeoff settings are: ITT is 1083 Deg C, Torque is 19,600 in pounds and approx 1600 pounds fuel flow.Cruise power: ITT is 1010 degrees C, Torque is around 11000 in pounds, fuel flow approx 1200 pounds fuel flow.As aircrew, we usually set one set of the gauges for cruise. Keep in mind that allthis proformance data is based on OAT, Pressure Altitude and takeoff factor. The proformance book for the C-130 is half the size of a big yellow pages book :0) My two cents WorthFly Safe :0)Dave

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Dave,What happens if you loose the #1 engine? Do the other blades just go to full pitch?Thanks,Jason

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Thanks Dave! Very interesting stuff.I did figure out my problem...first, I was attempting to use the prop pitch keys to adjust the prop RPM rather than just using the clickspots on the throttle. Then when I did start to use the clickspots, I pushed the levers all the way forward to the "AIR START" position, rather than to the "RUN" position. I did a flight with them in the "RUN" position and everything looked fine, good prop animation, and takeoff power seemed just great. So now I know, just set it and forget it!I just wish they'd put the ground idle speed controls on a popup window, and not exclusively in the VC (same with the interior light controls)--or are they, and I just missed it?Lewis "Moose" GregoryDurham, North Carolina

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Hi Jason,If the engine should fail, the aircraft will yaw terribly to the malfunctioning engine as the prop is driving the failed engine and no longer producing thrust. A negative 1200 ( + - 600 ) inch pounds of torques is sensed, the NTS system will cause the prop blade angles to increase pitch, trying to reduce the amount of negative torque.However, the NTS system will be no match for a failed engine, and at a negative 6000 in pounds, the reduction gearbox will decouple from the engine shaft, thus allowing the prop RPM to return to near 100 percent. It is able to do this because a decoupled gearbox has very little drag. The prop will continue to rotate but will be producing very little thrust and poses a risk of an uncontrollable prop situation, so aircrews are trained to (cage) the prop by moving the condition lever to feather at the moment of determined engine failure which also lessens the Yaw action as the prop blades have been featered to the 92.5 degree pitch angle.Sorry, Kinda Long WindedIn short, the prop will not automatically go to feather at engine failure. It has to be done manually ( Condition lever, fire handle, or prop override button ) :0)Fly safe

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Hi Lewis,Near as I can tell so far, the LSGI buttons and lighting controls are in VC only.Also, glad to hear you were able to find the condition lever control solution. BTW, you probably already knew this, but the airstart position is just used for engine restart in-flight. When you go to airstart, the electrical hydralic standby pump turns on and provides pressure to "unlock" the feathered blades and move them towards flat pitch where the airstream will do the rest and accelerate the prop to 100 % as governed by the prop assemby valve housing.Just more trivia :0)fly safe

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