I suspect the key phraseology here is if you are keeping the A/T engaged to touchdown use Vref +5, otherwise, if you are disengaging the A/T prior to touchdown I would think normal procedures (speed corrections) apply). Perhaps one of our resident 767/757 drivers (Tim757 or BBall) can put this to rest for us?Kevin in CYOW

What does the double white bug represent?

Greg,"What does the double white bug represent?"The double white bug represents the landing reference speed (VREF) appropriate to the landing configurtion.Best Regards,

Thanks.

I'm a bit surprised the approach speed would be different with/without A/T engaged, in particular comments about flying at VREF +5 no matter the wind conditions if A/T engaged. This surprises me because a heavy jet is suceptible to wind shear and might not be able to accelerate quickly enough if it suddenly loses headwind or gains tailwind. This basically comes down to mass and the time it takes for the engines to spool up, so I don't see how A/T setting suddenly overrides the physics. At least those are my thoughts on the subject.Lee Hetherington (KBED)

Well I'm not sure what to say, this is quoting directly from the COA 757/767 flight manual:Note: When using A/T to land, position the MCP selected speed bug to VREF+5 knots, regardless of computed additive.

"I'm a bit surprised the approach speed would be different with/without A/T engaged, in particular comments about flying at VREF +5 no matter the wind conditions if A/T engaged."I believe the reason given to the pilots for this is simply that the aircraft can respond more quickly to changes than humans (especially humans distracted by having to look at all flight parameters, not just airspeed, during approach)."This surprises me because a heavy jet is suceptible to wind shear and might not be able to accelerate quickly enough if it suddenly loses headwind or gains tailwind."There are restrictions placed on the use of automation in really bad conditions (e.g. strong headwind/crosswind components)if they are known beforehand, but, as you say, windshear presents special problems... Thank heavens for GPWS with Windshear detection ;-) Of course, technology has run amok.... Newer Weather Radar systems now have Windshear aural/visual warnings so you can see it coming.http://members.ozemail.com.au/~b744er/PWSTest1OJT.jpgHope this helps.Cheers.Ian.P.S. I can't seem to view my attached pics? Can anyone see them? Thanks.

Hi Ian,Your picture is appearing clear here. By the way and to the risk of sounding totally stupid how di you get this picture?Michael

"Hi Ian,Your picture is appearing clear here."Thanks, Michael....I realized what I was doing wrong.... I was using ".JPG" instead of ".jpg" in my http address".....how did you get this picture?"A combination of all of the following...Access to a Boing 747-400 (c/o of my job as an aircraft maintenance engineer)Aircraft powered up and IRS's aligned."TEST" selected on the Weather Radar Control Panel on the pedestal"WXR" selected on the EFIS Control PanelDigital Camera ;-)The Weather Radar test also produces some very loud aural warnings advising the pilots "MONITOR RADAR DISPLAY", "WINDSHEAR AHEAD....WINDSHEAR AHEAD"... and "GO AROUND.....WINDSHEAR AHEAD".Only the small central pie slice-shaped part of the multicoloured test display indicates the area of the windshear. i.e. the red and black striped section and the black and yellow bit tacked on the top.Hope this helps.Cheers.Ian.

Great job Ian! very interesting indeed. I am sure some smart brains will try to digest all these informations and maybe... who knows... figure out how to create new gauges incorporating all this.Michael

Ian,Remarkable technology!I've seen a few newer 767s equipped with such.