Flap Modes of Operation Flashcards
What are the different flap modes?
Primary (“C” Hydraulic)
Secondary (Automatic - electric)
Alternate (Manually Engaged - electric switch control)
When do engines go to Flight Idle?
When Flaps are Selected to 25 or 30
If C1 and C2 Hyd Pumps are Inop and Flaps are out of Up.
Flap Sequencing in Primary Mode
Flap 1 - Slats go mid-range and Kruger Flaps Extend
Flaps 5,15,20 - Inboard and Outboard trailing flaps move to position
Flaps 25,30 - Slats go Full first, then flaps move
Flap Sequencing in Secondary Mode
Flaps 1 - Slats move first to full down, then flaps move
Flaps 5/15/20 - Slats don’t move
Flaps 25/30 - Slats fully extend if not already, then flaps
- If slats are in mid position when Secondary Mode is engaged, they remain there until flaps 25/30 or Flaps UP
Flap Sequencing in Alternate Mode
Flaps 1 - Slats move with Flaps, Max slats is midrange
Max Flaps is 20, Max slats is midrange
When is flap extension inhibited?
Above 275kts
Above 20k feet
What is Auto Slat?
Augments stall protection
If in midrange position when aircraft approaches stall, slats extend automatically to down to increase lift.
*Only available in Primary mode
What flap modes are controlled by FSEU?
FSEU (Flap/Slat Electronic Unit) controls Primary and Secondary modes, NOT Alternate mode.
When do you have Flap Load Relief?
Primary at Flaps 15-30, NONE in Secondary or Alternate
When do you have Slat Load Relief?
Only in Secondary 256kts and below to Mid Position
When do you have Auto Slat?
Only in Primary at Flaps 1,5,15,20. None in Secondary or Alternate
What modes do you NOT have Flap/Slat Asym protection and Uncommanded Motion Protection?
Alternate mode
Do you have any relief or protections in Alternate Mode?
No.
