Cause BUFFET ALERT?

[fjsharry 0]

I was happened twice in cruise,and i found cause is"Current conditions result in a maneuver margin less than specified." in FCOM2.But i still can't get understand....Has anyone can explain detail..? And i always use ASE to get weather,so i was thinking could be by weather data change in cause. Thanks a lot.

[Jason-118 0]

I have only had this warning when you exceed your max calculated cruise level calculated by the fmc for your aircraft weight. Jason Paver

[Max Kraus 338]

All you can eat ? ed: oh now I know what you mean.. sorry

[Flexman 30]

It's called "coffin corner" for a reason :) Overspeed buffet and low speed stall speed become the same speed... and you're in trouble.

[RYR738 9]

I was happened twice in cruise,and i found cause is"Current conditions result in a maneuver margin less than specified." in FCOM2.But i still can't get understand....Has anyone can explain detail..? And i always use ASE to get weather,so i was thinking could be by weather data change in cause. Thanks a lot.

The FCOM Vol 2 page 1133 says !!!! "" Bring the airplane back within the operating envelope. "" Is your speed or altitude too high ???

[KevinMM 22]

A lot of parrotheads chartering flights to a concert... Oh wait, that's a Jimmy Buffet Alert!

[fjsharry 0]

@JASON I was set cruise altitude is by FMC calculated result.So i not get to high altitude. @Omar Before get buffet alert ,i was in stable cruise,then get buffet in the short time.I notice IAS drop down to yellow are.And buffet has two condition is overspeed and low speed??(Thanks you share this page)@Frederic I was meet "something" causing my IAS was drop down.And my speed and altitude is normal before.I just don't know what is reason....i know is low speed to receive alert message. @Kevin I was eat launch before,this alert could be for other people...

[CT1 5]

hmmmm

[RYR738 9]

In the first pic you have no autopilot engaged. ??? In the second pic CWS P is the pitch mode.You are climbing in to a stall !!! Are you flying the plane manually with LNAV and VNAV engaged ? Buffet Alert would be normal in this case.You are about to stall the plane.

[fjsharry 0]

@FredericIn first pic,i was disengage AP,then i try to control to stable.Second pic i was forgot circumstances....No i was always receive buffet in AP control condition.Maybe i fly more times try to find out the reason. So far i know if get overspeed or stall speed in the more high altitude then will receive BUFFET ALERT.

[baldwin2002 0]

If your speed is within the yellow zone, your airplane might loose aerodynamics and stall at a higher airpeed, within zone add flaps to maintain altitude or descent to lower altitude. Or just research it in internet to find answer/solution. It only took me me one minute to find answer for you same problem. Go back to props!!! Some people....

 

[pcubine 143]

You are fixin' to buy the farm.

 

Michael Cubine

[davierosoft 13]

Do you use weather programs like active sky or similar? If yes it could be the cause of your troubles if you don't set smooth change in weather conditions.

[kevinh 409]

If your speed is within the yellow zone, your airplane might loose aerodynamics and stall at a higher airpeed, within zone add flaps to maintain altitude or descent to lower altitude. Or just research it in internet to find answer/solution. It only took me me one minute to find answer for you same problem. Go back to props!!! Some people....

Leaving aside the unfriendly and unhelpful tone, this is not correct.  If your airspeed falls into the yellow buffet zone you are not likely to "lose aerodynamics" and stall at a higher airspeed.  Your stall margin is decreased, but your stall speed is unchanged.  You certainly should not add flaps in a high altitude cruise situation.

 

An aircraft can never lose aerodynamics unless it flies into a vacuum, i.e. at the edge of space.  This happened to X-15 pilots but isn't likely to happen in an airliner.

 

Sure people can google answers rather than ask questions you might regard as beneath you here.  But it seems your google search wasn't very informative.  The whole point of this forum is to get relevant and informed advice.  If you don't know the answer, don't reply.  Certainly don't resurrect an old, already answered, thread to add inaccurate information.

[flyerboy 114]

WOW - You dug up a post from 2011 just for that - and thats your first post..

 

amazing