FMA position on PFD

[aussiesteve]

Could any one tell me if there is a reason why the FMA's are positioned at the top of PFD?

[TopBunk]

I would suggest that it is derived from the basic scan for instrument flight, in which the prime instrument is the attitude indicator. Being placed at the top of this makes them central to the process. If you were to place them in any other location, especially anywhere away from the major scan flow, then it would mean a change to the decades old and proven scan flow, and mean any significant (and possibly unwanted) changes being more likely to be missed.

[gums]

Think TopBunk nailed it.

When the Earth was still cooling, we had the basic "T" scan for the instruments, with ADI at the top and airspeed and altitude on either side. Vertical velocity and such closeby. We also had the old turn needle/slip doofer just below the ADI or as part of it. But normally, it was the RMI/compass. You know, VOR and RDF and TACAN stuff there.

When the first HUD's came out in late 60's and early 70's, we had the same thing, with heading/course at top. Also had pitch lines, and vertical velocity was a bug on the altitude scale.

[aussiesteve]

Brilliant,

I had heard somewhere that it was to break up the IF scan, that just sounded completely wrong.

Thanks TopBunk and gums.