Sideslip in Cruise - Jets
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On the A320,
MCDU -> AIDS -> ALPHA CALL UP -> ALPHA DISPLAY, then type SLP1 (or SLP2). it will show the estimated sideslip with a good resolution (100th of a degree if I remember). You could also look at the drift angle to cross check if any doubts, by typing DA1.
Flex
MCDU -> AIDS -> ALPHA CALL UP -> ALPHA DISPLAY, then type SLP1 (or SLP2). it will show the estimated sideslip with a good resolution (100th of a degree if I remember). You could also look at the drift angle to cross check if any doubts, by typing DA1.
Flex
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Flexpwr
<<You could also look at the drift angle to cross check if any doubts, by typing DA1.>>
This can be helpful to visualize drift angle, but drift angle has nothing to do with a sideslip.
D
This can be helpful to visualize drift angle, but drift angle has nothing to do with a sideslip.
D
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Right, I should have added "in no wind condition", so to have an extra reference. Althought I concede it is hard to have zero wind in cruise.
If you still read a drift with a known no xwind condition, then the measuring or calibration may not be accurate.
If you still read a drift with a known no xwind condition, then the measuring or calibration may not be accurate.
Moderator
This cannot be detected on the sideslip indicator (which will show zero slip) but the yaw string will tell you the truth.
Which sideslip indicator did you have in your initial ME training ? I was limited to simpler aircraft which didn't have such gadgets .. nothing even on the 737/727 told me much about slip ? ... on the other hand, love B's Concorde slip gadget ..
If you are referring to the ball, this should be viewed as a lump of stuff on the end of a bit of string and sensitive to forces - it has no way of knowing what the air outside is doing ? Indeed, one can make it show any indication one might find attractive by manipulation of the controls.
Likewise, wings level after the initial things are done and the aeroplane has settled into steady state flight, it will just show the net force direction in its plane of operation .. ie gravity going straight down. I can't really see how one can deduce much at all about slip angles from a balance ball ?
I am quite uncomfortable with the apparent views of folks that the ball is a slip indicator ... albeit that it generally will give gross indications.
The yawstring, once "calibrated" (if I may misuse that term) will, indeed, tell you a lot about what the wind outside is doing.
Which sideslip indicator did you have in your initial ME training ? I was limited to simpler aircraft which didn't have such gadgets .. nothing even on the 737/727 told me much about slip ? ... on the other hand, love B's Concorde slip gadget ..
If you are referring to the ball, this should be viewed as a lump of stuff on the end of a bit of string and sensitive to forces - it has no way of knowing what the air outside is doing ? Indeed, one can make it show any indication one might find attractive by manipulation of the controls.
Likewise, wings level after the initial things are done and the aeroplane has settled into steady state flight, it will just show the net force direction in its plane of operation .. ie gravity going straight down. I can't really see how one can deduce much at all about slip angles from a balance ball ?
I am quite uncomfortable with the apparent views of folks that the ball is a slip indicator ... albeit that it generally will give gross indications.
The yawstring, once "calibrated" (if I may misuse that term) will, indeed, tell you a lot about what the wind outside is doing.
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Thanks to all for the inputs - exactly the very high level of discussion I've come to expect from pprune!!!
Keep it coming!
The slip ball measures something, but what exactly it measures is hardly ever discussed technically. It certainly does not measure sideslip!!
Keep it coming!
The slip ball measures something, but what exactly it measures is hardly ever discussed technically. It certainly does not measure sideslip!!
