wb2002,

The speed brakes on the 767/757 are less effective than the 727. The speed you are flying at the time of deployment also had some bearing.
Above 250 knots the spoilers tend to "blow down" or be less effective since the angle of the deployment is less than at lower speed. The area of the speed brake is also smaller than the 727 which also has some blow down.

Try this:

At cruise altitude (FL300) and at high speed ( M.80 ) with the autopilot on, give this a try.

First just close the throttles and see the speed bleed from say M.80 to M.75. Time it.

Next, do the same, but after you close the throttles, deploy the speed brakes and time it as well.

Now in lower altitude fly the plane at 250 knots, 10,000 on the autopilot. Do the same test as above. First just close the throttles then use the brakes and see the difference.

BTW, you can use the speed brakes with any flap setting something that is verboten in the 727. You can also use the speed brakes on approach if needed, but keep an eye on the speed!

The 757/767 is a very clean plane and hard to slow down. The 757 being a bit harder than the 767. It takes some planning to make crossing altitudes in both planes. You can either use the default / key to deploy or in VC, you can grab the handle and use just small amounts or anything in between. I would always try to sneak on the brakes so as not to disturb the passengers since there will be some vibration with deployment.

Let me know what you discover in this test.

I find they work pretty much as they do in the RW.

Lou