Airbus bank vs Maneuvering speeds

[longobard]

By definition maneuvering speeds protect from stick shaker in current configuration in 15° banks adding a 25° overbank protection.

1-Is there then a reason why FCOM defines Vapp as a maneuvering speed? For sure it's lower than Vstall (or stick shaker) at 40° bank (15+25).

2-Why in HDG lateral mode FD commands 25° bank below maneuvering speeds? I suppose that in a manual flight with no FD an instructor wouldn't be happy to see a guy banking 25° below maneuvering speeds...

all comments appreciated..

[Fursty Ferret]

Might be completely misinformed here but my understanding is that at and above maneuvering speeds you can manoeuvre up to the limit of +2.5g (+2g in Conf 1 and above). Below these speeds you get whatever the aeroplane is capable of giving and will see bank angle reduce accordingly.

[longobard]

My questions was different..

[foxmoth]

Which Airbus are you talking here? No stick shaker on 320/330.

[Fly3]

There are no stick shakers on any Airbus aircraft these days.

[A4]

From the 320 Series FCOM

The AP /FD Limits bank angle as follows:

• 15 ° when the aircraft speed is below the maneuvering speeds (F, S, or Green
Dot speed) -10 kt

• Then linear increase to 25 ° up to maneuvering speeds (F, S, or Green Dot
speed) -3 kt

• 25 ° above maneuvering speeds (F, S, or Green Dot speed) -3 kt.

For Engine Out it's the same.

I'm not sure I understand your question. Basically VAPP is manuveur speed in CONF 3 or CONF FULL - why would you want to bank > 25° at this stage? Even on a circling approach (FD's off) you shouldn't bank more than 25°...... and VAPP is going to be VLS+5 so, theoretically, at VLS+2 (maneurver-3) you can still get a commanded angle of 25°.

A4

[hetfield]

My airbus had a stickshaker:).

But it computed maneuvering speeds the wrong way, e.g. increasing bank - speeds lowered and v.v., a well known bug, nobody cared for....

[longobard]

A4

except in OEI situation HDG lateral mode will lead to bank 25° whatever the speed, try it

[FlightPathOBN]

Where do the 40° bank angle come from?

The max is 30°, but you cant see that... The FMS will command to 25° and leave 5° internally for course change while in the turn....

[Lord Spandex Masher]

40 is 25 plus an allowable over bank of 15 degrees which equals your 1.3g manoeuvre limit.


How do you get the 'degree' symbol?!

[mm43]

How do you get the 'degree' symbol?! Just Copy & Paste from the previous post. The actual HTML code is ° but this forum will not accept it.

[PA38-Pilot]

Just Copy & Paste from the previous post. The actual HTML code is ° but this forum will not accept it.

I know this is completely off topic, but ALT+167 works just fine ---> º

[john_tullamarine]

Can't speak to Apple, but on the MS variants, one conveniently finds all the non-keyboard symbols in the character map applet. On my installation that is located at

Windows\System32\charmap.exe

[longobard]

So nobody has explanation on the hdg mode vs below maneuvering speeds logic?

[compressor stall]

At FL370 at 0.78 if you are in managed NAV you will get 15* in a 90 deg turn. Pull HDG and you get 25*

[longobard]

sorry compressor stall,

that's not the point of the topic...