757 Airspeed bug placement
 

Good Day, I noticed that Boeing in the 757 have their airspeed bugs set at ref 30 then at ref 30 plus 80 and 100 in cruise flight. What is the reason for this?

Cheers
Novato

Vref30+80 is min clean speed, depending on the phase of flight. And Vref30+100 is a good pointer to engine out speed, give or take a couple of knots.

I personally have mine set to the flap schedule (vref30+40, +80) until top of climb then set Mmo and Vref30+100 for the cruise.

We don't have SOPs on what should be set on the ASI except during approach and take-off, so its down to individual pilots.

Also Vref+100 is min clean speed above FL200 (where flaps are also no certified for use)

Normal SOP where I work is double bug Vref30, Vref30+40 and Vref30+80 for normal flap schedule, but does not have any SOP for setting of bugs in cruise.

Thank you so much for the replies.

You mention Vref+100 is that the same as Vref 30 +100?

cheers