Does anybody know the maximum speed for deploying the speedbrake in NG or 747? I couldn't find it in the manual, or this mean we can deploy the speedbrake anytime we want. How about in the real aircraft?-Djoko-

Use it at will. My only experience of "flying" large jets is in a SAS full motion B767 sim in Stockholm, but there certainly was no hesitation from the pilots in using max speed brake there. I can

According to airplane approval criteria, the speedbrake must be usable up to VMO/MMO. That means you can use the speedbrakes at any speed.Best Regards,Christian GrillTOPCAThttp://topcat.ofplan.net

>Does anybody know the maximum speed for deploying the>speedbrake in NG or 747? I couldn't find it in the manual, or>this mean we can deploy the speedbrake anytime we want. How>about in the real aircraft?>>-Djoko-Mach 5. :)

The 744 has a "flight detent" (won't allow your lever to go back past a certain point in the air) It's an electrically controlled locking mechanism.The 767 has a fly by wire speedbrake system, and limits the angles of the spoilers by different amounts after takeoff.It's not recommended that you pull the lever all the way back on a 737NG (there is a flight detent, but there is no physical interlock to stop you pulling the lever all the way back).Hope this helps.Cheers.Q>

Thank you for all the answers and great explanation. I was just affraid to break the wings off. Now I don't have to worry again, since the speedbreak is designed that way. I'm sure it is safe to deploy at Mach 5 :D -Djoko-