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eddychewingum

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core_pfieldgroups_2

  • First Name
    Bart
  • Last Name
    Brackx

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  1. Ok I see but if you loose an engine at Vcef then the speed will decrease to zero if we stop. If you follow the acceleration to stop line the speed is increasing not decreasing...
  2. Hello, Maybe I am wrong but shouldn't the acceleration-stop and acceleration-go be swapped? Bart
  3. @ PerfManJ: Ok let me try to repeat this and tell me if I am correct: To find the correct CFL ( during mission accomplishment off course ) I use the wind correction as said in the 777 ( 50 % HW and 150 % TW ). To find the Vcef I use the uncorrected CFL with the Vcef wind correction grid on Vcef chart OR the corrected CFL with the Vr wind correction grid. You say that it should be + or - the same but I still have a few kts difference. Also in theory if we use 100 % wind just for trying out it should be the same but the difference is even higher. I can see what you say and I believe you because I found an example that is done this way. The only thing is that I would like to know why and I want to prove it because that is what I will try to do in my briefing which will be given on a training day to the whole squadron.. so I can expect some questions;) As I said before the correction grid for Vr for me is only + or - the wind to see the exact refusal distance. IAS to GS. Can you copy paste that part of the 1-1 for me? Also if you use only one correction to avoid double correction is that also for the nose wheel correction? thx
  4. Gentlemen, and perhaps lady's Thanks for all the info and explanations. I think in the end the concept is all the same. Something surprises me in the last post it is said that if we use the wind correction in the CFL chart we don't use in the Vcef chart? Why is that? In the SMP777 it is not said not to do that. E
  5. @NATOP1 it is indeed not very clear but Vr is only the speed at witch we can stop on the remaining runway. The acceleration part I understand but still it does not impact the performance I would think. If for a theoretical reason we use 100% wind factor The point Vr will always be the same for a giver gross weight. Would you think wind impacts acceleration that much? In the end this comparison is made in the Vcef vs Vr and acceleration is implemented in Vcef calculations. Correct me if I am wrong. I am tryin to make a briefing on this to finally clear this up because this question is asked a lot in our squadron. If you want I can send you a draft of it. Can you maybe forward me that section of your 1.1? We use SMP777 so I don't have that part.
  6. I am writing a paper on this question. The influence of wind on Refusal or Vcef. For refusal speed it is in fact very simple. It is only a correction from Indicated airspeed to groundspeed. In fact the point Refusal drawn on a runway is always the same point for a given gross weight. In fact it is a distance not a speed. So for every not headwind it will increase refusal with one knot. Offcourse this is only when we use 100% wind what we never do. Just theoretically this is correct. For the effect of wind on Vcef it is different. Headwind helps us for takeoff so CFL will decrease which makes that Vcef increases.
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