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Guest mhurocy34

FMC Landing Speeds Corrections

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Guest mhurocy34

Hope that the title was not too misleading, but here's my question.I am quite familliar with programming the FMC in PMDG 737, but one thing remains a mystery. My issue, Isn't landing at a speed of 240kts a little excessive? I notice that on the legs page during a flight that everything up until the landing procedure for instance and ILS is fine, .780/FL320 for example at cruise, and as I am making my step descent to final, my speed / alt readings on the FMC would be 240/8492 then 180/2500 then on the ILS line, 240/640 what's with the jump from 180 to 240? 180kts is acceptable to land, and the plane stops with moderate runway left at the nose, but 240kts? I modify the 240 back down to 180, and haven't attempted to let the FMC land me at that speed risking parking in a row of trees, or in PHNL's case, the Pacific.My question, both in simulation, and real life... Is this right? I rotate at 160Kts, and land at 180Kts, but is it possible to safely land at 240 kts? I'd rip off my gear if not my flaps first.Thanks!Miklos

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Guest EISN_CONTROL

ummmm....Rotation speed should be around 130-140. I've never had higher, despite loading this baby to it's maximum TOW.Landing at 180 KIAS is not acceptable, if you've planned your fuel correctly,you should only have your reserves and contingency fuel left going over the threshold, meaning landing speed should be about 135,give or take a few.As I understand, in real life, pilots use the MCP speed while flying the ILS. Not VNAV, as the ILS is a precision approach and will handle all vertical and Lateral profiles for you.240/8492, 240 is the speed set in the descent profile page when under 10,000ft. There are 3 ways of changing this.1)Change it on the legs page2)Adjust the speed in the DES page3)Not recommended,but you can extend your flaps and the speed will auto adjust.8492 is just you computed alt crossing the waypoint.180/2500,you've specified these contraints to the FMC so it will automatically adhere to them provided the aircraft is in LNAV/VNAV.240/640 is auto calculated aswell, why not change this value?when on the approach,set the aircraft in VREF and goto the INT page, you'll see all your speeds there.I suggest you programme the Legs pages using these speeds. Add +5 to the Final app speed, that'll be the speed crossing the thresholdJohn http://homepage.eircom.net/~eamonnmca/images/logo_ba.JPGwww.bavirtual.co.uk Senior Captain Simflight.com Staff Reviewer

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Guest mhurocy34

Thanks, I'll try the DES changes. I do admit, my speed settings are a bit high, but usually I load the plane just below the red line in the load manager. I'll lighten the load a bit, and try to get those speeds around the 130-140 mark (g). Yesterday, I was making an ILS approach into KSTL, at flaps 30 with gear down, I was at or around 130kts, and dropped short of the runway. I would assume that this is poor planning on my part as far as remaining fuel and general weight of the aircraft. I'll do some sperimenting, and see what gives.Miklos

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Guest wee_davie_2612

Try using the APPROACH REF page in FMC, that should maybe help you out. Chapter 8 page 47 of the flight manual. You should be flying the approach at Vref + wind correction. You should bleed the correction off during very short final (i.e. crossing the threshold) so that you touch down at Vref speed.Wind correction = Half the steady wind plus the full gust upto a maximum total of 20 knots added. E.g. wind is XXX@10 gusting 15 - add the half the steady (10/2=5) plus the whole gust (15-10=5) so you'd fly the approach at Vref+10I fly with the planes loaded all the way up to Max ZFW. Yesterday I landed at Max LW (stronger than expected tailwind) and the Vref for flaps 30 was 133kts. 180kts is waaay too high a speed to be landing at.Hope this helpsCheersDavid

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Guest boxjockey99

This is 300 series info but here's how we do it,The take off speeds as have been mentioned before are way high, 130-140 is more like it, the climb to 1000ft should be done at V2+15. if you just left click on the RSK button next to the take off speeds it will give you the right speeds assuming you have input a flap setting to use. The landing is genrally done in APR mode or VOR/LOC & V/S or HDG &V/S the latter used for non precision approaches. VNAV is used in the descent and is generally taken out as soon as you start to get vectors and altitudes from radar as you need direct speed control. if however you do fly the full VNAV procedure in VNAV then you should be looking at Arming the VOR/LOC mode prior to intercepting the LOC ie when you are on your 30ish degree intercept. Once established on the LOC you should go to APR mode and this will follow the glide. As soon as APR mode is active the MCP speed window willopen and you have direct control of the speed. Bear in mind if you are going to do the procedure in VNAV you should seriously look at what speed you need to fly in order to get your gear and flap out. You should technically be flap 5 speed 180 by LOC intercept and then as soon as the G/S starts to come down from the top of the scale the following occurs:G/S alive - Gear down Flap 15 speed 150G/S 1 dot above - Flap 25 speed 140 (or Vref30/40 +5ktG/S half dot above flap 30 speed Vref30 +5 (140 if using flap 40)G/S intercept (if using flap 40) take flap 40 speed Vref40 + 5ktLanding at 240kt puts you above your gear limiting speed and just above your flap 1 limiting speed so you are coming in clean and with no legs.... hope you like fireworks as you'll get the ones on the runway followed by the ones in the chief pilots office afterwards.Landing with jammed or asymetric flaps will result in a much higher landing speed, flap up is Vref15 +40 which is insane not to mention very sphincter tighteningly frightening so be very wary! Oh and fly it onto the deck in this case as any kind of flare will without doubt strike the tail! If you need more details just shoutKris

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