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Guest vortovor

Use of spoilers?

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Hello,At what speed after landing do you use your spoilers?Because the moment I use the spoilers at +/- 120 knots, they automaticly flip up again (that for a several time's, till I have a speed of 80/90 knots or so)?.....is that wrong or just normal?Thanksvortovor

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This will be the FIRST thing you will check for upon TD. With the speedbrake armed (approach checklist) the spoilers will (should) deploy but the PNF checks and if not deployed will deploy them manually. I have studied this for the 767 but not yet on the 737. On the 767 with ARM and compression on the main struts will deploy the spoilers *or* reverser engagement. In fact it's the spoilers that are the main factor contributing to help slowing the aircraft and saving the brakes from major over heating.Randy J. Smith

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-->" In fact it's the spoilers that are the mainfactor contributing to help slowing the aircraft and savingthe brakes from major over heating."This is not entirely true: the thrust reversers take the biggest part of the thrust reduction, not the spoilers. The spoilers "spoil" the lift so you have a firm contact with the ground, otherwise it would not have full contact and the brakes would not have that much effect. So the spoilers improve the braking effect and the thrust reversers take up some of the desceleration. So it is important to get those spoilers out immediatly to improve braking capability.

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"...with the ground, otherwise it would not have fullcontact and the brakes would not have that much effect..."Hey Kenneth, both planes are equipped with antiskid systems, and that's what will reduce the brake pressure when the ground contact is not optimal to avoid skidding tires. (just for info ;))

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Thanks all!But still I have no answere on my question ;)After landing with the A/P and A/T disconnected (I fly the plane manual around 2000 feet for landing) the spoilers goes down again when I want to deploy them. Its like the plane refuse to deploy his spoilers at a sertain speed...only when I am at around 80 knots I can deploy them?...is this automatically set by the plane?Thank again,vortovor

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Hmmm, seems like I can deploy spoilers at any time by pressing the / key on my keyboard. To retract them I press Shift-/(equivalent of the ? on the keyboard). At that point it shows that my 'Speed Brake' is armed. So I just press Shift-/ again to disarm the Speed Brake, if I'm wanting to disarm it. Does this help answer your question?Hope it helps,Jimmy Richards

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The spoilers if armed will deploy at >60kts and 2 of the 3 ground sensing as far target (struts compressed)To the original question, spoilers should be out as soon as you touch the ground.The problem you get i cant get it to do here DennisLicensed on the B737NG and the Airbus 319-321 as a technician (B1 and B2)

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This is not entirely true: the thrust reversers take the biggest part of the thrust reduction, not the spoilers. The spoilers "spoil" the lift so you have a firm contact with the ground, otherwise it would not have full contact and the brakes would not have that much effect. So the spoilers improve the braking effect and the thrust reversers take up some of the desceleration. So it is important to get those spoilers out immediatly to improve braking capability. This is also not entirely ture =). You missed my point which is this, without spoilers deployed your braking is reduced up to 60% since like you pointed out they spoil the wing lift and places the aircraft's weight on the main gear. As for the reversers here's what the manual says;"Reverse thrust always reduces the "brake only" stopping distance, brake and tire wear. Reverse thrust is most effective at high speeds." Now give me the spoilers without the reversers anyday for stopping... [h5]Best Wishes,Randy J. Smith [h4]P M D G 7 3 7 NG[/h4]http://img.villagephotos.com/p/2003-8/196432/mineimage.jpg [h3] Realism on the horizon [h5]AMD XP 2200 |MUNCHKIN 512 DDR RAM |ECS[/b ][i] K7S5A MB[/i] |GF2 MX 32 MEG and still runs GOOD!|WIN XP PRO |MITSUBISHI DIAMOND PLUS 91 19"[/h5]

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I think Boeing's stopping distances are calculated with max brake's and spoiler's only? Jim

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Step one. On approach to the runway say about 2500ft, checklistFlap: ready for landing flapSpeed: Set for landing vrefgear: downSpoilers: Armed (shift + / and confirm green "Spoilers Armed" on the MCP)as you land, you should hear the spoilers deploy (and the green light disapear, and on panel Shift-8 the spoiler lever should move down)If you press the / button now, the spoilers should not move, but if you hit shift - / then the spoilers will retract again. (bad move)in otherwords, well before you touchdown, arm the spoilers, and don't touch them again till you vacate the runway.

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>in otherwords, well before you touchdown, arm the spoilers,>and don't touch them again till you vacate the runway.In fact, with autospoilers, they automatically retract upon the first application of forward thrust - obviously necessary in a balked landing, and it also works when you accelerate after coming to a complete stop after clearing the runway.Tim MetzingerCommercial Pilot

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yep, when you add thurst (move out of reverse thurst, past idle) the spoilers will retract.From a United Airlines Airbus Pilot: Brakes are relatively innefective until 60-70 knots depending on runway and weight conditions, that is why reverse thrust is necessary until then. You come off reverse thrust, and then add brakes, in the airbus, the autobrake system will automatically add brakes once you are at the optimum speed to brake. (Normally you dont press on the brakes at 120 knots, more like 60-70) I know on a short runway, you would use the brakes as they will add stoping power, but it is definitely more comfortable to back off the brakes until the speed is at 60-70 kts. ) (braking is never not allowed tho)Sopilers are also referred to as lift-dump system on some planes, they will keep weight on wheels and do also add a lot of drag, the flight detent is so that the ground spoliers do not extend, which would destroy the lift in flight and you could come dangerously close to a stall, if you aren't in one. IT is advised never to use spoilers with flaps extended.hope this helpsfor your origional q--use spoilers the second you are on the ground!

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"The spoilers if armed will deploy at >60kts and 2 of the 3ground sensing as far target (struts compressed):Just wondering how many more versions we can get of the logic required? :-lolHere's what my notes say..."During landing, the auto speedbrake operates when all these conditions occur:-The altitude is less than 10 feet (from the flight control computers to the "R/A greater than 10 ft" relays). -The main landing gear is on the ground or the main landing gear wheels spin up (Greater than 60kts)-The speedbrake lever is in the Armed position.Both left and right thrust levers are at idle."Does this mean that if the RA's are not working, the Speedbrake Lever Actuator also does not work. Here's one for Paul (grin)... Does the Autospeedbrake work if your plane is upside-down :-lol Unfortunately, my computer went up in smoke before I could check this out ;-)Cheers.Ian.

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>"The spoilers if armed will deploy at >60kts and 2 of the 3>ground sensing as far target (struts compressed):>>>Just wondering how many more versions we can get of the logic>required? :-lolMAY hehehe well it was only a comment to the main strut part, of course RA <10ft and thurst is at idle or lower (makes sense)As far as i know, the main struts compressed is the old 737 logic, then again, boeing change everything faster than you wanna believe :-DWell i checked my manual, may i ask if you are a tech or pilot? just curius :-) DennisLicensed on the B737NG and the Airbus 319-321 as a technician (B1 and B2)

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>in the>airbus, the autobrake system will automatically add brakes>once you are at the optimum speed to brake.That is so wrong, that im 100% sure of, i just finished the license less than a year ago (allso checked manual) BUT what it does do is that the braking curve is used as on all aircrafts, when you use reverser and spoiler then you can be on the curve without brakes (unless you use set autobrake to max) and the aircraft dont have to use the brakes, unless again if you hardly use the reverser then you need the brakes, when you get to a loweer speed spoilers dont really help much and then you need the brakes (as you said).Without reversers you really need brakes and the autobrake system still work, so you only have spoilers and brakes available so of course that is used.DennisLicensed on the B737NG and the Airbus 319-321 as a technician (B1 and B2)

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"Well i checked my manual, may i ask if you are a tech or pilot? just curius"Hi, Dennis.I'm a maintenance engineer.... licensed on the 747-400 (Avionics) and on the 767's and the 747 Classics (Radio trades only, however). Very little experience on 737's (all Line stuff and mostly Classic), but have access to some good books.. and can always pick the brains of those around me ;-)Glad to make your acquaintance :-)Cheers.Ian.

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>I'm a maintenance engineer.... licensed on the 747-400>(Avionics) and on the 767's and the 747 Classics (Radio trades>only, however). Very little experience on 737's (all Line>stuff and mostly Classic), but have access to some good>books.. and can always pick the brains of those around me ;-)Cool im educated as an aircraft mechanich (all areas of the aircraft, allso avionic) and then became a technician and flight engenir 2

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>From a United Airlines Airbus Pilot: Brakes are relatively>innefective until 60-70 knots depending on runway and weight>conditions, that is why reverse thrust is necessary until>then.I think this UA pilot was misinterpreted! Talk about Chinese Whispers!Brakes provide THE main stopping force and are applied upon main gear touchdown. Many landings are done with only reverse idle to reduce engine wear. I think this pilot was referring to the effectiveness of reverse thrust decreasing as speed is reduced, so the autobrake system applies more wheel brake force to maintain the selected constant deceleration rate.>(Normally you dont press on the brakes at 120 knots,>more like 60-70) I think the pilot was referring to when he comes out of autobrake and applies manual braking, he didn't mean that no brakes at all are used until then.I've found that the PMDG 737 doesn't deploy spoilers with weight on wheels, but only when reverse thrust is selected. Bug or FS limitation?Neil.Frozen ATPL and Jet Orientation Course complete on B737-700

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"I've found that the PMDG 737 doesn't deploy spoilers with weight on wheels, but only when reverse thrust is selected. Bug or FS limitation?" For the real NG here's how it works: You must have the Speedbrakes armed Thrust levers at idle Wheel speed (spin up) >60 knots + Radio Alt below 10 feet A landing gear strut compression (All including NOSE GEAR STRUT) - Flight spoilers with nose, left or right landing gear strut - Ground spoilers with right main landing gear strut only Reversers But even if the spin up is not detected, the ground sensors (strut compression) will deploy them. For RTO they can be deployed by reverser thrust also (Being in the DOWN position on TO run), once you apply forward thrust they will automatically retract.[h5]Best Wishes,Randy J. Smith [h4]P M D G 7 3 7 NG[/h4]http://img.villagephotos.com/p/2003-8/196432/mineimage.jpg [h3] Realism on the horizon [h5]AMD XP 2200 |MUNCHKIN 512 DDR RAM |ECS[/b ][i] K7S5A MB[/i] |GF2 MX 32 MEG and still runs GOOD!|WIN XP PRO |MITSUBISHI DIAMOND PLUS 91 19"[/h5]

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"I've found that the PMDG 737 doesn't deploy spoilers withweight on wheels, but only when reverse thrust is selected."Same here, Neil. This seems to be something which affects a lot of sims. For some people it will work, for others not. One thing which sometimes stops the spoilers working is the thrust levers not being at the idle stop... In some cases this can be due to joystick throttle calibration errors or joystick noise. In other cases, it could be the A/T not moving the thrust levers to idle fast enough during A/P-A/T coupled approaches or the pilot not doing fast enough during manual approaches.(To the PMDG team)Is "Idle" logic for spoiler deployment based on joystick throttle position or engine rpms? If rpms, is Approach Idle implemented in PMDG? The engines may be taking too long a time to spool down from Approach Idle to the trigger rpm point on some folks computers?Cheers.Ian

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Ian, I was just thinking about joystick calibration errors myself when I read Randy's post, you beat me to it.Will be interesting to see what the idle logic is from the PMDG guys.For the record, I've been landing manually, speedbrakes armed, no autobrake, and bringing the thrust levers to idle at 30ft RA.

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