Hello,We all know where the bugs go during takeoff and approach, but is there any specific configuration they should be in when cruising?I have found no info anywhere for this subject so thought I should post here.Thanks.Alex.

Does vary a little from person to person, but as a general guide this seems to work.Place one bug on your current Vref30.Place one bug on the holding speed.Place one bug on the engine out speed.Place one bug on the current speed.PIC has a 5th bug which our aircraft dont... so I guess you could just put two on the Vref or something!This config gives you as much useful information as possible on the ASI. The most important being the engine out speed, as it represents the minimum speed you would want to be going before commencing descent after an engine failure in cruise.Having a bug on current speed is useful in the event of failure of the command airspeed bug, and allows you to see if the cost index has been changed while you weren't paying attention.The holding speed is generally the lowest speed people are prepared to fly in cruise, as below this speed you venture too far into the bad side of the drag curve. Its worth remembering that if you had an engine failure while at the holding speed you would very very quickly need to start descending to avoid approaching a stall.Finally placing a bug on Vref is probably to make it all look pretty more than anything... it gives you an idea of where +80 is, in the event you had to run flaps for any reason (after descending below 20000ft of course).

HPSOV,Thanks for clearing this up. One thing though. At what point do the capt and f/o move the bugs from takeoff config to cruise config ? How common is it for airlines to have a cruise config ?Tero

At our airline, we just moved the bugs to minimum clean speed at the After Takeoff checklist, that is, VREF30+80, where the 'highest one', which was already at that speed, is joined by the other ones. This results in all the bugs being just about at the bottom of the airspeed indicator.Two advantages of this method:- You have a very quick visual indication what your minimum speed during cruise is.- You can instantly see that your approach speeds have not been set.

Hey thanks for that.How would I determine the engine out speed and the hold speed though?Is there any specific calculations?Thanks.Alex.

Ali,I checked with a friend who has over 3000 hours 75/76 time. He said that setting bugs in cruise was a technique at his airline. Mostly, after leveling off, and after checking O2 and fuel remaining, those wanting to plan ahead would pull up the destination atis, then add fuel remaining at destination to the ZFW. This will give you an estimated landing weight. Apparently, this helps reduce some workload during descent. Plug the estimated landing weight into the approach page to get estimated Vref. Then set your bugs to Vref, +20, +40, +60, and +80. These speeds are just an estimate and may have to be slightly readjusted during your descent check. The Vre+80 gives a good estimate for your descent/approach min clean manuevering speed.Again, this was "technique." Some guys would wait until descent to even touch their bugs while others would set them using other figures. Sounds like it just depends on what the pilot wants to do. . .at least at his airline. Hope this helps you.

Thanks a lot.It's just a matter of what to do out of the two people that have suggested different things.I would probably go for the latter as it is easier, I would just calculate my VREF and press the "magic button", that sets all the bugs for me. Then I would wait until just about to start descent and reset them again.....there might be small changes.I just saw a video of a 767 and they had two bugs on around their VREF in cruise, and another two bugs on around 230kts. Can anyone explain this?Also, some people tell me, set two speed bugs on VREF speed for approach, when others say just one. Maybe someone can shed a little light on this.Cheers.Alex.

Interestingly our flight crew training manual (assume it originates from the Boeing version) states that the bugs should be set to Vref30, +40 and +80 (which is how we set them, unlike PIC) for the planned landing weight, as someone stated above.However not a single one of 500 767 pilots set them that way (perhaps the manuals need ammending?) as this really achieves nothing. Setting them as I described above in my mind provides for the most effective use of them during cruise. They are usually set to these figures at TOC, and reset to approach (Vref, +40 and +80) at TOD. We always set two bugs on Vref, one on +40 and one on +80.Alex in the video they most likely had two bugs on Vref, one on holding, and one on engine out (which at lowish weights would be around 230kts). To find these two speeds simply go to the holding page for the holding speed (Vref +80 at low weight, +80-+100 at high weights), and select the engine out cruise page to find the engine out speed.At the end of the day it really is something that is up to the individual pilot, and the culture within the airline.

Thanks I think I will just stick with the two bugs at VREF, then one at +40 and one at +80, during the cruise.It is how I have always done it before.Thanks for the input.Alex.

HPSOV,Could you clear something up for me ?PIC sets them like Vref, +20, +40, +60, +80 which can directly be used for minimum man. speeds, and thus I always extend flaps by the bug speeds, ie. flap 1 before +80, flap 5 before +60, flap 20 before +40 and flap 30 before +20. How do you figure out the flap5 and flap30 setting speeds if you don't actually have the bugs visible. Do you just do it by "seat of the pants", or mentally add up the 20 kts slices.For example, you're approaching +60 and it would be time for FLAP5 (actually FLAP20 if we're thinking of them as transient speeds :), but I think that's useless in deceleration), how do you know when to extend it AT LATEST, if you don't have the bug in there to remind you. Or do you do the mental adding up ?Tero

It's easy to see the halfway point between two bugs to see +60 and +20 during the approach.Setting your speed bugs for approach during climbout on a long flight would increase chances of errors, if circumstances change, you need to divert and land with a different weight. You may not remember whether you set them using the latest weights data or forget it, thinking you probably did it two or three or four hours ago.

Its funny, because when I first used PIC and saw that there was a bug on every flap speed it just seemed to make so much more sense! But, our manuals state that we must set 2 on Vref, 1 on +40 and 1 on +80. Basically you just remember the speeds, you need to know atleast the last digit to set it accurately (its too hard to pick a knot or two on the ASI). If Vref was 134, then +80 is 214, this is the speed that would be in the window as you decelerate to flaps up speed. When you run flaps one its simply a matter of subtracting 20 from the speed in the window, so 194 would be next, then 174, 154 and finally Vref+5. These can all be confirmed by making sure they look right on the ASI (bug halfway between +40 and +80 for +60).If I was in charge I'd probably go for a bug on each speed, it makes things a little easier, however I imagine there is some logic behind the way we do it.

Ah, but then we had the speed tape on the EADI, which of course does show every flap speed and is actually more used during those phases of flight. :)