Wind correction on finals

[tfm 169]

In the 747X and 767X FMS there is a page telling you (among other things) the current headwind component.Is there any equivalent for the MD-11? I can see that the FMS adds +5kts to vRef for vApp, but it doesn't seem to make any automatic allowance on top of that for head/tail winds on landing.Tim

[emvaos 13]

Tim,You must be confusing the 747 and 767 with Airbuses. Neither of the above two aircraft automatically compensates for wind at arrival. To begin with they do not even know what that is (unlike the MD11).The +5 increment is added by default byt the FMS (irrespective of the wind prevailing) and is editable by the pilot. The FOM of the 747 notes that the +5 increment is sufficient in case the AT is intended to be used all the way to landing. In any other case VApp can be adjusted by the pilot, as much as he/she deeems necessary. The same is true for the MD11 where VApp is also **editable** by the pilot. Hope this clarifies the situation.Vangelis===================================== E M V Precision Manuals Development Group www.precisionmanuals.com=====================================

[michal 44]

The proper procedure for making Vref correction due to wind while on approach is use winds as reported by the airport. Do not use winds calculated by FMS. The winds that FMS calculated may be completely different than winds close to the runways and clearly your FMS can't give you those winds.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

[tfm 169]

I may be confused, but not about this! I don't suggest that the FMS on the 747X or 767X add a wind component automatically: obviously they don't - and I'm amazed that the Airbus FMS can do it.But the FMS on the 747X and 767X do identify a headwind component. I realise it's better to use winds as reported by the airfield. But sometimes it is just as well to double-check and, frankly, in the simulator, to cheat.Anyway, I just wanted to know if the MD-11 tells you the headwind component; I cannot find it; and I guess from the responses to this post take the answer is "no".Tim

[Shmiffy 0]

Hi Tim:The FMC in the MD11 will not tell you the headwind component for the arrival runway. However to a certain extent, you may tell it.On the Desc Forecast page you may input the winds at varying altitude at arrival, just like the 744, and most likely, the 76. Within the MD11, it will also permit you, and indeed find very useful, the current surface wind speed, direction, and local temperature where;LSK - EGLL/090/10 14C - RSKFor example.CheersPaulPS - Not sure if you need the C there, i beleive it 'remembers' that you used C on the takeoff and init pages, so assumes C on arrival. Provided your airline doesnt change the SOP's mid flight ;)

[michal 44]

>But sometimes it is just as well to double-check>and, frankly, in the simulator, to cheat.There is no reason to "cheat" even in the simulator. Surface wind is such a critical piece of information for a pilot (runway selection depends on it!!) that if you don't know it you may as well look at the windsock or go to another airport. Whatever weather program you use in FSX - this information is available to you. Using FMS calculated winds for this purpose is really a very bad practice. It is really ABC of meteorology that winds at 1000 ft can be totally different than surface winds.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

[Shmiffy 0]

Michael:You reminded me of a very famous mishap regarding landing with a tail wind....http://findarticles.com/p/articles/mi_qn41...s_/ai_n13995636CheersPaul

[mfrantz 45]

>In the 747X and 767X FMS there is a page telling you (among>other things) the current headwind component.>>Is there any equivalent for the MD-11? I can see that the FMS>adds +5kts to vRef for vApp, but it doesn't seem to make any>automatic allowance on top of that for head/tail winds on>landing.>>TimTim,You can see the current headwind and crosswind componends on the ND anytime (except when there is no wind or you are not on the ground) by changin the option of wind display from "arrow" to "cross" from the Addons->PMDG Options menu (Airline display options tab).

[3-2-1-Now 126]

Hi,The aircraft is not aware of the headwind, nor compensates for it at all - it flies indicated airspeed; all the wind does is affect ground track and ground speed.If you watch the aircraft in a cross wind, you will see that it flies with a certain crab angle. This is simply to maintain the ground track. You will also note that with a headwind, the GS is lower than it otherwise might be.In zero wind, GS = TAS.TAS increases approximately 2% above IAS per thousand feet.IN ZERO WIND:Altitude = 4000 ftIAS = 180 kts.TAS = 180 + (4 x (180 x 0.02)) = 3.6 x 4 = 14.4 + 180 = 194 kts.GS = TAS = 194 kts.WITH A HEAD WIND:If you have a 20 kt headwind component:TAS = 194 kts.GS = TAS - headwind = 194 - 20 = 174 kts.Best regards,Robin.

[tfm 169]

> You can see the current headwind and crosswind componends on the ND> anytime (except when there is no wind or you are not on the ground)> by changin the option of wind display from "arrow" to "cross" from> the Addons->PMDG Options menu (Airline display options tab).Now THAT is an answer to my question.Thank you.TimPS: Thanks to the others too - but I wasn't really looking for a flying lesson (not that I couldn't do with one).

[tfm 169]

Someone from the PMDG team has answered my question (a post or two down) but I agree that the ability to enter destination winds is a nice touch - and an interesting variant on the Boeing versions.Ta,Tim