nr1jc Posted August 9, 2012 Share Posted August 9, 2012 Hi, had a head to head with the hind and got my right engine blown by its cannon, tried different meassures to get the engine to run again but failed every time, had enough power in left engine to RTB, but as i was trying to restart right engine and riding the throttle up and down to see if i could read any difference in the gauges. only thing i found out was that at off or low throttle was giving me higher air resistance from the fan... so the question is what is the best way to leave your throttle at when engine is damaged inflight?? even better is there a way to free the fan so its not mechanicly conected to the rest of the engine [sIGPIC]www.vjokers.no[/sIGPIC] Link to comment Share on other sites More sharing options...
WildBillKelsoe Posted August 9, 2012 Share Posted August 9, 2012 Hi, had a head to head with the hind and got my right engine blown by its cannon, tried different meassures to get the engine to run again but failed every time, had enough power in left engine to RTB, but as i was trying to restart right engine and riding the throttle up and down to see if i could read any difference in the gauges. only thing i found out was that at off or low throttle was giving me higher air resistance from the fan... so the question is what is the best way to leave your throttle at when engine is damaged inflight?? even better is there a way to free the fan so its not mechanicly conected to the rest of the engine If the throttle is off, or at idle, the fan is not rotating as it should, reference windmill restart to get the idea. AWAITING ED NEW DAMAGE MODEL IMPLEMENTATION FOR WW2 BIRDS Fat T is above, thin T is below. Long T is faster, Short T is slower. Open triangle is AWACS, closed triangle is your own sensors. Double dash is friendly, Single dash is enemy. Circle is friendly. Strobe is jammer. Strobe to dash is under 35 km. HDD is 7 times range key. Radar to 160 km, IRST to 10 km. Stay low, but never slow. Link to comment Share on other sites More sharing options...
BlueRidgeDx Posted August 9, 2012 Share Posted August 9, 2012 A failed engine will windmill in the slipstream regardless of throttle position, and moving the throttle cannot/will not change the amount of drag caused by a windmilling engine. If the engine was on fire, shut it down with the fire handle and place the throttle to Cutoff; don't try to restart it. If the engine was damaged, but is still running (and not not on fire), leave it running until you're out of the threat environment and/or in no danger of colliding with the ground or anything attached to the ground. The engine is still providing electrical power and hydraulic pressure, and is probably providing useful thrust that might be required to ensure terrain clearance. "They've got us surrounded again - those poor bastards!" - Lt. Col. Creighton Abrams Link to comment Share on other sites More sharing options...
Sierra99 Posted August 9, 2012 Share Posted August 9, 2012 even better is there a way to free the fan so its not mechanicly conected to the rest of the engine >POOF< Done... The fan isn't connected... ( Of course it never actually was connected ;) ) It spins freely. Unless there is physical damage to the fan it will spin freely once the engine is shut down. What causes drag are the accessories connected to the engine such as generators, hydraulic pumps etc. http://www.globalsecurity.org/jhtml/jframe.html#http://www.globalsecurity.org/military/systems/aircraft/systems/images/tf34-image02.jpg||| As you can see there are lots of parts and pieces... (Perhaps Cali can jump in here with a little more info about how and where those items connect to the engine) Gadgets [sIGPIC][/sIGPIC] Primary Computer ASUS Z390-P, i7-9700K CPU @ 5.0Ghz, 32GB Patriot Viper Steel DDR4 @ 3200Mhz, ZOTAC GeForce 1070 Ti AMP Extreme, Samsung 970 EVO M.2 NVMe drives (1Tb & 500 Gb), Windows 10 Professional, Thrustmaster Warthog HOTAS, Thrustmaster Warthog Stick, Thrustmaster Cougar Throttle, Cougar MFDs x3, Saitek Combat Rudder Pedals and TrackIR 5. -={TAC}=-DCS Server Gigabyte GA-Z68XP-UD3, i7-3770K CPU @ 3.90GHz, 32GB G.SKILL Ripjaws DDR3 @ 1600Mhz, ZOTAC GeForce® GTX 970. Link to comment Share on other sites More sharing options...
viethson Posted August 9, 2012 Share Posted August 9, 2012 There might also be engine failure situations where the fan or N2 shaft will just stop rotating because of a torn and now blocking turbine blade or something. In this case there will be no windmilling. This of course is a serious damage to the engine and no restart should be attempted. The engine must be shut down completly with the fire handle pulled. Throttle of this engine in idle of course. But I am not sure if this is simulated. Link to comment Share on other sites More sharing options...
viethson Posted August 9, 2012 Share Posted August 9, 2012 >POOF< Done... The fan isn't connected... ( Of course it never actually was connected ;) ) It spins freely. Unless there is physical damage to the fan it will spin freely once the engine is shut down. What causes drag are the accessories connected to the engine such as generators, hydraulic pumps etc. http://www.globalsecurity.org/jhtml/jframe.html#http://www.globalsecurity.org/military/systems/aircraft/systems/images/tf34-image02.jpg||| As you can see there are lots of parts and pieces... (Perhaps Cali can jump in here with a little more info about how and where those items connect to the engine) Gadgets accessories are always connected to the N2 shaft not the fan. So as long as the N2 shaft keeps spinning, also windmilling with a certain rpm you still get hyd pressure, generator maybe also bleed air Link to comment Share on other sites More sharing options...
BlueRidgeDx Posted August 9, 2012 Share Posted August 9, 2012 accessories are always connected to the N2 shaft not the fan. So as long as the N2 shaft keeps spinning, also windmilling with a certain rpm you still get hyd pressure, generator maybe also bleed air That's true, but its entirely dependent on the particular engine, since generator cut-in speeds are different, and windmilling RPM is dependent on IAS. For some older aircraft/engine combinations - and usually on long haul flights - a windmilling engine that's not providing enough oil pressure can eventually seize due to bearing failure. Not good, when you're hours away from a suitable alternate and critical fuel... In any event, the TF34 doesn't windmill fast enough in cruise flight to continue providing electrical/hydraulics. The generator will trip offline at 52% N2, and the hydraulic system bleeds off within 60 seconds. Bleed air cannot be extracted from an engine thats not running. "They've got us surrounded again - those poor bastards!" - Lt. Col. Creighton Abrams Link to comment Share on other sites More sharing options...
BlueRidgeDx Posted August 9, 2012 Share Posted August 9, 2012 As you can see there are lots of parts and pieces... (Perhaps Cali can jump in here with a little more info about how and where those items connect to the engine) That picture is mislabeled...it's a TF39, not a TF34. You can tell because the TF39 has a one-and-a-half stage fan with fixed IGVs, and a 6-stage LPT. The TF39 is recognizable as the engine that powers the C-5A/B. 1 "They've got us surrounded again - those poor bastards!" - Lt. Col. Creighton Abrams Link to comment Share on other sites More sharing options...
viethson Posted August 9, 2012 Share Posted August 9, 2012 Thanks for the details on the engine :thumbup: Link to comment Share on other sites More sharing options...
Sierra99 Posted August 9, 2012 Share Posted August 9, 2012 That picture is mislabeled...it's a TF39, not a TF34. You can tell because the TF39 has a one-and-a-half stage fan with fixed IGVs, and a 6-stage LPT. The TF39 is recognizable as the engine that powers the C-5A/B. I think the picture is upside down too... :music_whistling: [sIGPIC][/sIGPIC] Primary Computer ASUS Z390-P, i7-9700K CPU @ 5.0Ghz, 32GB Patriot Viper Steel DDR4 @ 3200Mhz, ZOTAC GeForce 1070 Ti AMP Extreme, Samsung 970 EVO M.2 NVMe drives (1Tb & 500 Gb), Windows 10 Professional, Thrustmaster Warthog HOTAS, Thrustmaster Warthog Stick, Thrustmaster Cougar Throttle, Cougar MFDs x3, Saitek Combat Rudder Pedals and TrackIR 5. -={TAC}=-DCS Server Gigabyte GA-Z68XP-UD3, i7-3770K CPU @ 3.90GHz, 32GB G.SKILL Ripjaws DDR3 @ 1600Mhz, ZOTAC GeForce® GTX 970. Link to comment Share on other sites More sharing options...
nr1jc Posted August 9, 2012 Author Share Posted August 9, 2012 A failed engine will windmill in the slipstream regardless of throttle position, and moving the throttle cannot/will not change the amount of drag caused by a windmilling engine. If the engine was on fire, shut it down with the fire handle and place the throttle to Cutoff; don't try to restart it. If the engine was damaged, but is still running (and not not on fire), leave it running until you're out of the threat environment and/or in no danger of colliding with the ground or anything attached to the ground. The engine is still providing electrical power and hydraulic pressure, and is probably providing useful thrust that might be required to ensure terrain clearance. Thanks, seemed like there was some connection between throtle position and IAS, must have been some coincident with other variables [sIGPIC]www.vjokers.no[/sIGPIC] Link to comment Share on other sites More sharing options...
Recommended Posts