nightlynx Posted October 11, 2010 Posted October 11, 2010 I've been getting the L HYD PRESS warning come on when landing. I hammer the brakes usually since I come in too fast, is this normal for the pressure to go down the more you use the brakes? I thought as long as everything was working i.e. engines and hydro pumps that there would be a constant supply of high pressure available for things like the brakes. I thought maybe I blew a tire or something but everything looked fine. Oh yeah, I LOVE THIS SIM!
Echonomix Posted October 11, 2010 Posted October 11, 2010 (edited) I've had these happen too. I think it happens because you slowly lose hydraulic pressure while pressing the brakes. If you let up for a second it should rebuild and you can brake again. It could also be a bug, I'm not sure. Be sure to deploy full speed brakes upon touchdown too. Edited October 11, 2010 by Echonomix break != brake asus p7p55d deluxe | intel i5-750 @ stock | g.skill ripjaw 4gb | asus geforce gtx 470 @ stock | trackir 4 | thrustmaster hotas warthog | win7 home premium 64bit
nightlynx Posted October 11, 2010 Author Posted October 11, 2010 Haha speed brakes?! Yeah maybe I should use them next time.
BladeLWS Posted October 11, 2010 Posted October 11, 2010 It could be a bug or it may be the pressure demand on the pump. The left system controls left rudder, left elevator, left and right ailerons, flaps, landing gear, wheel brakes, and nose wheel steering.
deephack Posted October 12, 2010 Posted October 12, 2010 If I had to guess I'd say that at idle the engine isn't providing enough energy to run the hydraulic pump hard enough to counteract the hydraulic load of the brakes in use. https://www.youtube.com/user/deephack
Zenra Posted October 12, 2010 Posted October 12, 2010 Stuff like this is just great, and could just as appropriately be posted in the "Little details that you've noticed?" thread. I haven't seen this but will try jumping on the breaks more and see what happens. It might be fun to save a track, replay and watch how low the pressure drops on the gauge. Just because it goes low enough to set off the warning is not necessarily a bad thing - presumably the system still has some pressure, the breaks still work, etc. Great stuff! Zenra Intel i7 930 2.8GHz; ATI HD5850 1GB; 1TB Serial ATA-II; 12GB DDR3-1333; 24 x DL DVD+/-RW Drive; 800W PSU; Win7-64; TM Warthog HOTAS
Headspace Posted October 12, 2010 Posted October 12, 2010 I get the same thing as well, always when landing, throttle back to idle position and brakes engaged.
Scabbers Posted October 12, 2010 Posted October 12, 2010 what color is the warning? Now where is that speed brakes control again? [sIGPIC][/sIGPIC]
chaos Posted October 12, 2010 Posted October 12, 2010 (edited) With engines idle, hydraulic pressure would be more than sufficient to operate the brakes. Even with the pumps not running, there would be enough pressure in the accumulator to brake (i.e. hydr. failures). "Pumping" the brakes is not smart as you're forcing the anti-skid system to continuously cycle in an effort to find maximum brake pressure for existing runway conditions. This will increase your stopping distance. Especially during hydr. failures you should refrain from pumping as the accumulator will only allow a maximum of 5 applications before pressure drops below safe levels (A-10A). Besides, as anti-skid is not available with alternate brakes, you'd be well advised to brake cautiously because you may blow a a tire. It would be interesting to see if ED actually modelled this anti-skid behaviour. Edited October 12, 2010 by chaos "It's not the years, honey. It's the mileage..."
Scabbers Posted October 12, 2010 Posted October 12, 2010 With engines idle, hydraulic pressure would be more than sufficient to operate the brakes. Even with the pumps not running, there would be enough pressure in the accumulator to brake (i.e. hydr. failures). "Pumping" the brakes is not smart as you're forcing the anti-skid system to continuously cycle in an effort to find maximum brake pressure for existing runway conditions. This will increase your stopping distance. Especially during hydr. failures you should refrain from pumping as the accumulator will only allow a maximum of 5 applications before pressure drops below safe levels (A-10A). Besides, as anti-skid is not available with alternate brakes, you'd be well advised to brake cautiously because you may blow a a tire. It would be interesting to see if ED actually modelled this anti-skid behaviour. UM there is no ABS in aviation. you stand on the brakes you blow tires. pump the brakes Now where is that speed brakes control again? [sIGPIC][/sIGPIC]
slug88 Posted October 12, 2010 Posted October 12, 2010 UM there is no ABS in aviation. you stand on the brakes you blow tires. pump the brakes Page 101 of the DCS: A-10C pilot's manual: 4. Anti-skid Switch. Prevents landing gear from locking when braking when enabled. [sIGPIC][/sIGPIC]
chaos Posted October 12, 2010 Posted October 12, 2010 UM there is no ABS in aviation. you stand on the brakes you blow tires. pump the brakes Okay, I'll email flight-technical of our company and tell them they've been wrong all along. Might as well get Boeing and Airbus involved as well. :-) "It's not the years, honey. It's the mileage..."
robmlufc Posted October 12, 2010 Posted October 12, 2010 UM there is no ABS in aviation. you stand on the brakes you blow tires. pump the brakes Anti-skid = ABS :smartass:
Ragtop Posted October 12, 2010 Posted October 12, 2010 UM there is no ABS in aviation. you stand on the brakes you blow tires. pump the brakes Maybe not in grampappies Piper Cub, you're playing the big leagues sonny boy :P:pilotfly: 476th vFG Alumni
5by5 Posted October 12, 2010 Posted October 12, 2010 ...there's definitely anti skid on the Dash-8 Q400 I flew this morning. It's an absolute necessity for my home airport! Specs: AMD 5900X, Asus X570MB, EVGA3090FTW, 64Gb 3200 RAM, 2x M.2 Drives, Reverb G2 Hotas: Virpil Stick and CM3 Throttle, TM Warthog, TM TPR Pedals, Realsim FSS Stick, Honeycomb Alpha and Bravo, Brunner CLS2 Yoke, Motion/Haptics: DOF P6 Platform, Jetseat Additional: TM MFDs, Tek Creation F-16 UCP
ARM505 Posted October 12, 2010 Posted October 12, 2010 Yeah, aviation is actually the original home of ABS (antiskid) technology, but anyway. Back OT, I've also seen this - one press of the pedals should not result in a constant rate of pressure loss, and even at idle the hydraulic pumps should be able to maintain pressure.
Steve Davies Posted October 12, 2010 Posted October 12, 2010 The loss of L-HYD pressure is a realistic feature, not a bug. Steve Davies https://www.10percenttrue.com
Echonomix Posted October 12, 2010 Posted October 12, 2010 The loss of L-HYD pressure is a realistic feature, not a bug. Thanks for confirming. I don't pump the brakes on rollout. I usually hold them until just before I get the caution and then I'll coast for a bit while I watch the pressure build back up, then if I need to, I'll apply more brake. Usually though, if you hang around in ground effect too long, or come back to base with most of your weapons on your wings, you shouldn't need that much brake. Don't forget the speed brake either! asus p7p55d deluxe | intel i5-750 @ stock | g.skill ripjaw 4gb | asus geforce gtx 470 @ stock | trackir 4 | thrustmaster hotas warthog | win7 home premium 64bit
Scabbers Posted October 13, 2010 Posted October 13, 2010 Anti-skid is not the same thing. with abs you can stand on the brake and your car controls pumping the brakes. The anti skid in an aircraft (atleast the ones i work with) gradually releases pressure to prevent a complete lock up. it does not pump your brakes. Crew is taught to never stand on the brakes in the aircraft unless it is a last resort(landing). hence my point. pump em. you can apply brakes with alot of intesity on taxi. but my post was dealing specifically with landing. Exactly prevents locking. but doesnt pump your breaks. but hey what does 20 years aviation(military) maintenance know about anything. Now where is that speed brakes control again? [sIGPIC][/sIGPIC]
Eddie Posted October 13, 2010 Posted October 13, 2010 Crew is taught to never stand on the brakes in the aircraft unless it is a last resort(landing). Indeed, this is I suspect the cause of the L-HYD caption here. There should be no reason to apply full brake pressure when landing, except in an emergency. You should be able to slow to taxi speed on even the shortest runway in the DCS world with no more than a few seconds of around 1/4 - 1/2 braking force. Tbh I've often been able to land with nothing more than a short dab of wheel brakes to bleed off a few knots before turning off the runway. Of course if you don't have pedals with brake axis and are using the keyboard you can be forgiven ;). It's a pity brake fires/overheating isn't moddeled.
chaos Posted October 13, 2010 Posted October 13, 2010 ... Crew is taught to never stand on the brakes in the aircraft unless it is a last resort(landing). hence my point. pump em. But hey what does 20 years aviation(military) maintenance know about anything. Maybe take a re-fresher course... ? Joking!!!! :-) Like Eddie said; there's no need to stand on the brakes (unless you have to make due with the "W" key for braking like I do). Pumping the brakes is discouraged because it doesn't do anything except increasing your stopping distance. With every brake-application, you're forcing the anti-skid system to re-calculate how much pressure should be bled in order to prevent the wheels from locking up. It can take up to 3 seconds for the system to calculate how much pressure should go to the brakes. I assume the military systems work on the exact same principle. I've been flying for 22 years now (currently B777) and still learning every day... 1 "It's not the years, honey. It's the mileage..."
Scabbers Posted October 13, 2010 Posted October 13, 2010 we teach em to pump on our aircraft. as for your I can not claim knowledge to equipment or procedures. but pumping is for coming in hot not for normal use. normal use is a couple seconds of brake and let it roll out. pumping is not inteded for all brake applications. i hope that made sense. Now where is that speed brakes control again? [sIGPIC][/sIGPIC]
Scabbers Posted October 13, 2010 Posted October 13, 2010 On topic of the L HYD PRESS. can any confirm what color the indication is. If I remember correctly when the pressure drops it shows yellow as a caution. then if there is no pressure or the pump faults it shows red. Can a dev confirm this for the game? is this modeled Now where is that speed brakes control again? [sIGPIC][/sIGPIC]
power5 Posted October 13, 2010 Posted October 13, 2010 I stand on the brakes every time and seems I will not stop in time every time. I usually am slow enough by the last turn off. Clean aircraft after a sortie. Am I doing something wrong? [sIGPIC][/sIGPIC] Aaron i7 2600k@4.4ghz, GTX1060-6gb, 16gb DDR3, T16000m, Track IR5 BS2-A10C-UH1-FC3-M2000-F18C-A4E-F14B-BF109
Eddie Posted October 13, 2010 Posted October 13, 2010 Am I doing something wrong? You're most likely either landing too far down the runway, too fast, not using the airbrakes to slow down, not using the anti-skid or a combination of all of them.
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