Airbus and FPA

[Kestrel_909]

Hello,
Curious as to what FPA (Flight path angle?) mode on Airbus glareshields is and what it is used for? I know it uses track instead of heading but what about the vertical speed, what difference is there with it in FPA when setting it on the glaresheild?

Thanks

[NWSRG]

FPA is Flight Path Angle. Allows the pilot to select a descent angle, rather than a ft/min descent.

[Kestrel_909]

Our paths keep crossing Nosewheel Steering, I'm guessing that's what your name is?:ooh:

Thanks for that.

[TopBunk]

K909

As to what it is used for - mainly for non-precision approaches (NDB, VOR, LLZ only). The FPA part looks after the descent profile in so far as groundspeed changes affect the required rod, the track part loks after the heading changes required to make good the inbound track as the drift varies through changing wind velocity or ias.

[Kestrel_909]

Thanks Topbunk!

[NWSRG]

Kestrel,

Nose-wheel steering never crossed my mind...but now that you have pointed it out to me, I like it!

NWSRG is something much more mundane.

[JABBARA]

FPA, that is the same as in B 737 NG. It simply indicates where the aircraft goes in relation to horizon. For example, if it is below the horizon 3 degrees, that means the airplane is descending with 3 degrees in relation to level, regardless of any other parameter like speed, pitch, vertical speed etc. Probably the information is provided by IRs only, not pitot-static.
Its lateral deviation from center indicates the actual track of airplane in relation to heading. So if there is no wind and the airplane is flying level, its position should be centered over horizon. If you need some more detailed information about this, I can write later.