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dmiannay

Which Vref to Choose?

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Hi Folks,I have to say that in all my many years and hours (3200 +) enjoying the many releases of MSFS, the PMDG 737NG series clearly exceeds all other add-ons I've tried! Kudos to the team for what I believe to be the preeminent FS payware product to-date!That said I

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If you correctly fill out the FMC, you can get the REF speeds by clicking the "INIT REF" button while your approach or the Approach page (both the same, but the INIT REF is a shortcut). Remember 30REF and 40REF differ by airplane. For the 900, it's usually a 10 knot difference but in the 700 in can be as little as 3. In most cases, you should use flaps 30 when the skies are clear, and flaps 40 when the runway is wet or windy.As for your bump, make sure you cross the runway at exactly VREF (make sure you look at your groundspeed instead of the IAS while landing).Nick B.Continental Airlines Virtual 737NG Pilothttp://www.precisionmanuals.com/images/forum/800driver.jpg--AMD Athlon XP 3200+ @ 2.2 Ghz (Equal to 2.8 ghz)400W Power supply3x 80 mm Case FansSoyo VIA KT600 Dragon PlusnVidia GeForce FX 5200 128 mb2 x 512 PC400100 GB Western DigitalMicrosoft Sidewinder Precision 2

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600-700 30 flaps. 800-900 40 flaps. Now you already look at rwy lengths conditions etc so you probably know these can change but in *general* these are used. The bounce has been talked about a great deal of late. I do not bounce, I have never bounced as have not many other users. But some folks do. Is this a autolanding? VREF + 5 set? WHat is the crosswind on the rwy? Do you have the CW limit handy? Are you using an add-on weather program? What is your landing weight? WHat is the landing flaps set to?Best Wishes,[h4]Randy J. Smith[/h4][h3]P M D G's 747-400[/h3][h4]coming to a runway near you[/h4][/font color]Caution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |

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Thanks Nick and Randy :) I really appreciate all the activity here and the willingness to help!Thanks for the better insight on which Vref to choose (30 or 40) and why. I'll stick with 40 since I fly the -800 most of the time.The bounce isn't too much of a problem for me... it's very slight (more like a rock skipping on water than a bounce) and a bit common since I end up flying commercially so much for my work. While "greasers" are always desired they are not always accomplished in real life. Instead of getting into all the particiulars for my landings I'll just read through the many threads on the issue and try and work it out. If I get stumped I'll come back for more advice.Thanks again!DougDell 8250 (3.06GHz/533FSB)1GB Rambus RAM120MB ATA 100 (7200 RPM)ATI Radeon 9700 Pro (Catalyst 4.5)Audigy 2 Sound (latest drivers)MS Force Feedback 2WindowsXP Pro (SP1)DirectX 9.0b

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Great Doug, glad that you are enjoying the bird! Another forum member made a very good post about this bouncing issue that I thought I would share."Daniel,you may have a good result but this is a technique which should be used to often.It's better to have a firm landing, than a soft landing.The bumps...must be a wrong landing speed as normally if you fly the approach Vref+5, and idle the throttles at about 30ft AGL, you'll have an airplane wanting to stay down in stead of an airplane wanting to fly. add a good pair of speedbrakes to this and you're set... not more bouncing... autolands may be automatic, it's still the pilot's job to continuously monitor the computer's actions and correct if necessary(that's why a CAT3 autoland can be so intense(i say CAN))Personally i'd never give extra thrust on finals, since you're a good bit above the stalling speed(times 1.3 correct??) you have room to do a better job on the flare. the autoland's flare is basically 'crap' but it'll give you a presentable touchdown rate IF you are on the right speed. Speed is everything on approach... remember that.Coming in too fast will make you bounce because there is enough 'energy' to get the plane up again, at the right speed, this is not so.Enlisted for Integrated ATP Course @ Aeromadrid, leaving here in October.Lenny Zaman - Tiesto forever Pretty good advice don't you think? Best Wishes,[h4]Randy J. Smith[/h4][h3]P M D G's 747-400[/h3][h4]coming to a runway near you[/h4][/font color]Caution! Not a real pilot, but do play one on TV ;-)AMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | Maxtor 6Y080M0 SATA 80 GIG | 512 DDR 400 | Windows Xp Pro | Windows Xp Pro 64 |

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Randy,Lenny's response is a bit confusing. He states "Personally i'd never give extra thrust on finals" Does this mean that he doesn't use Vref+5 so his T/D speeds are slower and thus the a/c will stay down better? Not sure I follow what he means. If I have a gross weight within range and I autoland with Vref+5 and flaps 40, the landing ought to be a greaser every time. Every flight in the -800 starts with a ZFW of 132,900 and is loaded with enough fuel to land with between 5000 and 8000 lbs. With essentially 10 kt or less crosswinds within 30 degrees R or L of the R/W centerline I have yet to stick a landing.Again I'm not to burdened about this but it is a bit of a curiosity.DougDell 8250 (3.06GHz/533FSB)1GB Rambus RAM120MB ATA 100 (7200 RPM)ATI Radeon 9700 Pro (Catalyst 4.5)Audigy 2 Sound (latest drivers)MS Force Feedback 2WindowsXP Pro (SP1)DirectX 9.0b

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Decided to do a little more testing on a flight from Cleveland to San Francisco. The picture below shows the status of my approach to KSFO 28L in the PMDG 737-800, Delta livery. I use AS2004 MR2 Build 131 as the external weather app (does a great job BTW :) ).Notice the following:GW: 141,000 lbs.Vref+5: 145ktsSpoilers: ArmedFlaps: 40Winds: 274/1328L Course: 283DA738_Arriving_KSFO_28L.jpgEverything seemed right where it should have been but... still bounced! :( There's some neat little trick here to grease the landings but no matter what I try I can't seem to crack the code.Back to the drawing board ;)DougDell 8250 (3.06GHz/533FSB)1GB Rambus RAM120MB ATA 100 (7200 RPM)ATI Radeon 9700 Pro (Catalyst 4.5)Audigy 2 Sound (latest drivers)MS Force Feedback 2WindowsXP Pro (SP1)DirectX 9.0b

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