Serben Posted September 19, 2012 Posted September 19, 2012 I have a problem with shutting down my engines. Everytime i do, i get a red "main gearbox" warning light and also the red master warning signal starts sounding off. Here's what i do after i've safely landed: i set collective to zero, set throttle to idle, then i close the red fuel shut off valves near the collective which stops the engines, and finally i engage the rotor brake. For some reason this seems to damage my gear box. What exactly am i doing wrong?
sobek Posted September 19, 2012 Posted September 19, 2012 Does it say main gearbox or something about oil pressures? Master warnings are normal when shutting down the engines due to causing fuel and oil pressures to fall below redline, thus causing the sensors to indicate a master warning. Good, fast, cheap. Choose any two. Come let's eat grandpa! Use punctuation, save lives!
Spetz Posted September 19, 2012 Posted September 19, 2012 Exactly. Once you start powering down, your hydraulic pressure, fuel pressure, voltage levels, etc all begin to lose pressure / power, therefore your warning guages will indicate the drop and set off warnings to alert you. Obviously, during flight, this is a bad thing. On the ground, not so much unless you are fully spooled up and ready for flight, which would indicate a problem.
Serben Posted September 19, 2012 Author Posted September 19, 2012 Ok so this is normal then? Also is my way of shutting down the engines correct? Or should i be doing something different?
sobek Posted September 19, 2012 Posted September 19, 2012 (edited) Usually you would be running the engines at idle for a up to a few minutes to allow all parts to cool down and minimize cooling shock, but apart from that, it sounds about right. Also, IIRC the rotor brake only engages below 5(?)% rotor RPM. Edit: I don't remember the waiting times for shutdown, but there is a maximum time in idle IIRC because the oil starts to heat up due to the oil cooling fan and pump that are running off the main gearbox running slower. I think A16 wrote about it somewhere, might be a bit hard to find by now though. Edited September 19, 2012 by sobek Good, fast, cheap. Choose any two. Come let's eat grandpa! Use punctuation, save lives!
Spetz Posted September 19, 2012 Posted September 19, 2012 Ok so this is normal then? Yes, this is normal.
Daniel M Posted September 19, 2012 Posted September 19, 2012 . Also, IIRC the rotor brake only engages below 5(?)% rotor RPM. I believe you are correct, (I wait til its past the "2"). Edit: I don't remember the waiting times for shutdown, but there is a maximum time in idle IIRC because the oil starts to heat up due to the oil cooling fan and pump that are running off the main gearbox running slower. I think A16 wrote about it somewhere, might be a bit hard to find by now though. I didn't think they actually simulated to this level of detail with the shark(not saying that you shouldn't do it though...). Would be a nice feature in the future to have your start up/shutdown affect your long term durability :smartass:
sobek Posted September 19, 2012 Posted September 19, 2012 You can actually watch the oil get hotter in BS, but i don't think that cooling shock is modelled. Good, fast, cheap. Choose any two. Come let's eat grandpa! Use punctuation, save lives!
Yurgon Posted September 19, 2012 Posted September 19, 2012 Also, IIRC the rotor brake only engages below 5(?)% rotor RPM. According to the manual (Normal shutdown procedure): "Engage the rotor brake when rotor RPM is less than 30%." And I've definitely managed to destroy the brake by applying it too soon, but 5% is a bit too far on the safe side. :music_whistling:
lokitexas Posted September 19, 2012 Posted September 19, 2012 Hmmm...thats odd. A/A guns and SAM's usually shut my engine down for me. i5 3570k @ 4.3 560ti GTX 2gig 8gig RAM Intel SSD Win7 64bit
Nate--IRL-- Posted September 19, 2012 Posted September 19, 2012 Hmmm...thats odd. A/A guns and SAM's usually shut my engine down for me. They also provide ventilation openings so you don't have wait for components to cool down upon touchdown. Very considerate. Nate 1 Ka-50 AutoPilot/stabilisation system description and operation by IvanK- Essential Reading
AlphaOneSix Posted September 19, 2012 Posted September 19, 2012 (edited) Normal engine cooldown times at idle prior to shutdown are 2 minutes in the winter and 1 minute in the summer (at my organization, we just use 2 minutes regardless of season). This allows the gas generator and power turbine discs more time to cool than if the engines were immediately shut down. The danger is that the engine casing will cool (and shrink) more rapidly than the turbine discs, and the discs could be damaged by rubbing on the engine casing. This possibility of damage is not modeled in the game, so there is no danger from immediately shutting off the engines after reducing throttles to idle. Edited September 20, 2012 by AlphaOneSix
sobek Posted September 20, 2012 Posted September 20, 2012 The disks expand when they cool off? That seems rather odd. Are you certain that it's not the casing that is cooling off faster? Good, fast, cheap. Choose any two. Come let's eat grandpa! Use punctuation, save lives!
AlphaOneSix Posted September 20, 2012 Posted September 20, 2012 (edited) The disks expand when they cool off? That seems rather odd. Are you certain that it's not the casing that is cooling off faster? Yes I have it backwards... The engine casing SHRINKS faster because it COOLS faster...I should not post so close to bedtime. EDIT: I fixed the post to explain it properly...thanks sobek! Edited September 20, 2012 by AlphaOneSix
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