Barber Pole

[asolo]

Could someone explain to me the reason for the barber pole on the a/s indicator? What does it mean and why is there one on the K-200 i fly, but not the c-90?

 

[erj-145mech]

Because your Vne changes with pressure altitude?

 

[EagleRJ]

Correct. Some aircraft have a flight envelope that changes with altitude. Some aircraft that have a moving barber pole are Mach-limited in addition to the knot limitation, and that is what the barber pole is representing.

 

[Snakum]

My Captain told me the barber pole exists in our B200 so I'll know how fast I can go to meet a crossing restriction after I dilley-dalley way too long before I start down and then trim like a punk once I do.

Minh

 

[dash8driver]

the barber pole is the minimum speed pointer for the last leg of the day. also known as Vllms (last leg min speed).

its also the point at which the beer horn sounds off.




.

 

[Foxcow]

Correct. Some aircraft have a flight envelope that changes with altitude. Some aircraft that have a moving barber pole are Mach-limited in addition to the knot limitation, and that is what the barber pole is representing.

Vmo v. Mmo right? Up high, you have to worry about mach buffet and all that jazz so Mmo is the limiting factor. Down low, you will run into your maximum indicated airspeed before you have to worry about Mmo so Vmo is the limiting factor. At some altitude, Vmo will equal Mmo.


I think...

 

[satpak77]

barber pole is a goal not a limitation

 

[MauleSkinner]

If you look in your C90 manual, you will probably find something that says Vne is reduced 4 knots for every thousand feet above a certain altitude...no barber pole, but you have to do it manually.

Fly safe!

David

 

[Beechman]

I set off all the bells and whistles today: barber poll (over-speed), stall warning (on landing in flare), gear warning (pulling power levers below 84%N1), no GPWS warning though...perhaps tomorrow (but it always goes off in the sim)!

 

[mike1mc]

If you look in your C90 manual, you will probably find something that says Vne is reduced 4 knots for every thousand feet above a certain altitude...no barber pole, but you have to do it manually.

There is a limitation. The C90B has a barber pole.