December 28, 200322 yr Is the proper landing speed Vref or Vref plus 1/2 the headwind speeds?I ask because approaching the runway fully configured and at Vref speeds tends to make the plane pitch up pretty high making it hard to see the approach.Presario
December 29, 200322 yr No one has any idea about this? Seems like a pretty important topic to me.. the FMC has a line under the Vref approach speed thats stuck on wind correction +5kts, I'm sure this in an inop button but it also raises the question of what's the proper approach speed, Vref or Vref plus 1/2 the headwind speed.. e.g. Vref 30 = 131kts Headwinds speed 12kts makes the proper approach speed 137kts.. is this right? anyone?
December 29, 200322 yr Hope this helps. On final approach, the airplane will react to windshear and gusts for both the headwind andcrosswind components of the wind. Unless compensated for, these factors may cause the airplaneto land short.
December 29, 200322 yr This is good information Howard thanks. I'm still confused about the proper MCP speed needed for a full autoland approach. In your message you say "With the autothrottles disengaged, use an approach speed wind correction of 1/2 the steady headwind component" does this mean that when autothrottle is engaged that Vref only should be placed in the MCP? Isn't autothrottle most usefull when landing?Presario
December 29, 200322 yr doing a full auto land (rare)when setting your flaps for landing v-ref +5 in M.C.P with no wind corrections and leave on auto throtlles. on a manual landing add the wind speeds.Howard
December 29, 200322 yr Hi, Very interesting indeed, Howard :) Now that you seem to know a lot about the subject, I will shoot a question: When setting up the speeds, and as you decelerate, at some point, there is a white bug on the speed tape. Now, I don't have the manuals here (am off on vacation), so I can look to see what it is for. Do you by any chance know that?Thanks :-waveBoaz
December 30, 200322 yr VREF + 15 BUG, I assume it's the same on landing........[h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/betaimg.jpg Randy J Smith
December 30, 200322 yr what he is seeing is "Bug 5", the white speed-ref bug that can be set up on the cockpit displays. It can be set with a little knob above your engine displays. Its called SPD REF Normally its on auto so all your speed bugs come from the FMC. However, you can manually set V1, VR, Gross Weight, VREF on the ground to override the FMC if you need too with bug5 (the 5th one you can set obviously) being just a pilot selectable speed for any reason he might need it. You can go out of auto mode and select bug5 to get all your automatic readings plus the airspeed you select too. Its sometimes handy for showing an ATC speed restriction on your speed tape.. hope this helps :)Howard
December 31, 200322 yr Reading this thread triggers a question I've had for a while now. What is the correct way to add flaps on approach to landing? I never know when exactly I should be at each flap setting.Let's say I have selected a 30 degree flaps approach. When should I be at 5, 10, 15, 25, and 30 degrees? And how should the plane be slowed down? Normally I stay at the last ATC speed (usually 250 knots) until I'm on an intercept course for the localizer. Then I slow to 180 knots and set 5 degrees flaps. When I'm established, I set 10 degrees and slow to 160. Then between 5 and 10 miles on final, I set the final approach speed and go to 30 degrees flaps.Should I instead by setting final approach speed as soon as I'm established, then add flaps according to the flap speeds placard as the plane decelerates?I'd love some input on the proper and realistic way to slow the plane and add flaps on approach.Thanks!
January 1, 200422 yr Here are some rules of thumb for an ILS:5 miles to G/S intercept: flaps 5 / speed 5 (on the 5 bug)1500 ft RA: gear down, flaps 15 / speed 151000 ft RA: flaps 30 / final approach speedThis is a low noise/low drag approach. A standard ILS or a non-precision approach would be:5-8 miles to final descent point: flaps 5 / speed 52 miles to descent point: gear down, flaps 15 / speed 151 mile to descent point: flaps 30, then 40 / final approach speedIz
January 1, 200422 yr From your INI REFS PAGE SELECT YOUR FINAL FLAPS SPEEDS. when maneuvering to intercept the localizer, decelerate and extend flaps to 5. Attempt to be at flaps 5 and flaps 5 maneuvering speed prior to localizer capture.When glideslope alive select flaps 15 gear down and arm speed brake.At glideslope capture observe the annunciation change. At this time, select landing flaps and VREF plus 5 knots or VREF + wind correction if landing manually, and complete the landing checklist.When using the autothrottles to touchdown, no additional wind correction to the final approach no speed is required. MAX FLAP SPEEDS. VMO / MMO
January 1, 200422 yr I wrote this 'equation' wrong in my tutorial, so my apologies.....The correect landing speed is VRef + (1/2 * wind component) + (gust componoent)So with the following conditions - wind 4 gust to 9, VRef of 135, you do:135 + (1/2 * 4) + 9 = 136 knots :)
January 2, 200422 yr Hmm well, to me, 135 + 2 + 9 is still 146 :)But the gust component in this example is not 9, it's 5 (9 minus 4 knots steady wind). So you would end up with 135 + 2 + 5 = 142 knots for FAS.
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