PPRuNe Forums - View Single Post - AF 447 Search to resume (part2)
View Single Post
Old 17th May 2011, 22:02
  #1659 (permalink)  
OK465
 
Join Date: May 2011
Location: BOQ
Age: 79
Posts: 545
Likes: 0
Received 1 Like on 1 Post
New guy to these discussions. I’ve read only about 200 pages of posts, some from Part 1, all of Part 2; so forgive me if I repeat something already covered.

The FPA/TRK discussion finally got me hooked.

The FPA-TRK mode, as I understand it, is an alternate FD display with command steering available for the FPV. The HDG-V/S mode is the primary FD display option with the dual-cue command steering for pitch attitude and bank.

The validity of the command steering for either FPA/TRK or HDG/VS is always a function of proper mode selection and annunciations per the FMA.

I guess what I’m getting at is once the FPV is selected is it always valid autonomously as an FPV regardless of the mode selected and the command steering indication. At high AOA, would the FPV not be visible on the PFD when outside the PFD displayed range of attitude versus actual FPA? Are the FD's removed?

Boeing allows the selection of the FPV on either PFD individually thru the individual EFIS control panels. In the HUD, if so equipped, Boeing always displays the FPV and command steering in the HUD is always for the FPV. If the FPV is out of the HUD FOV, it ‘ghosts’ (dashed outline) to indicate non-conformal situations. (The HUD & PFD FPV algorithms are very slightly different however.)

My other question: Is ADR "unreliable" the same as ADR "failed"? My understanding is that in ALT 2 you cannot re-engage the A/P with dual ADR failure.

I may know just enough to not really know enough however.

edit: the Boeing PFD FPV's, if selected, are added symbols to the PFD, the dual-cue FD steering is still for pitch attitude & bank
OK465 is offline