Flight Controls Flashcards
What are the 3 flight control modes?
Normal, secondary and direct.
How are the primary flight controls supplied?
Redundant hydraulic sources.
How are secondary flight controls, flaps and slats supplied?
Hydraulically with electrical back up.
What is an ACE and what functions do they serve?
Actuator Control Electronics. There are four units which receive input from pilot controls. They process the inputs and transmit the signals to multiple actuators on the primary control surfaces with no single ACE controlling more than one actuator on a given control surface.
How many PFC’s are there and what purpose do they serve?
There are 3 Primary Flight Computers. Signals from the ACE’s are combined with info from other sources such as air data, inertial data, slat position etc which are processed through the PFC’s and the modified data returned to the control surfaces via the ACE’s for enhanced handling qualities.
In Normal flight control Mode what is the basic methodology?
Pilot input/Autopilot>ACE>PFC>ACE>control surface
In Secondary Flight Control Mode what is the basic methodology?
Pilot input>ACE>SIMPLIFIED PFC>ACE>control surface.
How is Secondary Flight Control Mode selected?
Automatically. It cannot be selected manually. EICAS FLIGHT CONTROL MODE.
What does the EICAS “FLIGHT CONTROL MODE” indicate?
That there is an internal fault in the PFC or they have insufficient info to function normally and the system has reverted automatically to Secondary.
What functions are not available in Secondary flight control mode? In Direct?
Autopilot/auto speed brakes/envelope protection/gust suppression/TAC/yaw damping and in Direct manual trim cancel too.
How is Alternate Flap Mode selected?
Either automatically following a failure of all three PFC’s or it can be selected manually
In Direct Mode what is the basic methodology?
Pilot input>ACE>control surface
What does the EICAS “PRI FLIGHT COMPUTERS” indicate?
That the flight control system is in Direct Mode.
What are the three flap/slat control modes?
Primary (hydraulic), Secondary (electric), Alternate (electric)
Which hydraulic system supplies the flaps?
Center
