Flight Control Laws Flashcards
In Normal Law, what does Load Factor Limitation limit g to?
Clean config: +2.5 to -1g
Other config: +2 to 0g
In Normal Law, what does Pitch Attitude Protection limit pitch to?
30 deg nose up (can reduce to 20 based on config/speed)
15 deg nose down
In Normal Law what happens when High Speed Protection reached and ECAM warning and MASTER WARN lights activate?
Side stick nose down authority progressively reduced and ELACs command a pitch up order until airspeed reduced.
*does not prevent aircraft exceeding VMO/MMO.
High AOA protection (alpha prot) has priority over all other protections. It allows optimum performance for extreme conditions (eg. Windshear or GPWS). What are the 3 indications on speed tape?
VLS- flight guidance will not command an attitude resulting below this speed.
Va PROT- (top of amber barber pole) pitch command logic changes from load factor demand to alpha demand- side stick controls alpha directly.
AP will disengage and further nose up trim is inhibited.
Va MAX- (top of red band) max AOA that may be reached in normal law if full back sidestick held, aircraft will descend.
Alpha floor (only available in normal law) commands TOGA thrust when triggered. When is it available and when will it activate?
Available immediately after takeoff to 100ft RA on approach.
Typically half way between alpha prot and alpha max.
*not a fixed speed (not depicted on speed tape). Based on excessive or rapidly increasing AOA.
What AOB is bank angle hold available to?
What happens if you release side stick above this limit?
33 deg.
Positive spiral stability will return AOB to 33 deg.
*if alpha or high speed protection is active, positive spiral stability available at any AOB.
What AOB does bank angle protection limit to normally and with protections active?
Normally 67 deg.
At 33 deg auto trim deactivates. 45 deg FD removed & AP disconnects.
Alpha or high speed protection- 45 deg
How do flight controls work in ground mode and why?
Flight controls move proportional to side stick movement. This allows you to do a control check as well as rotate aircraft.
*automatic pitch trimming is inhibited until transition to flight mode shortly after takeoff.
For landing mode, at 50 ft AGL ELACs memorise pitch attitude. What happens next?
At 30 ft a gentle nose down is commanded which you naturally must counter with aft stick for the flare. This gives a conventional feeling for landing.
In alternate law, replaces Alpha Protection and High Speed Protection?
Alpha Protection becomes Low Speed Stability
-keeps VLS, but VSW (stall warning) replaces Va Prot and Max.
-if VSW approached, gentle nose down introduced, can be overridden and stalled.
High Speed Protection becomes High Speed Stability.
-above VMO/MMO, gentle nose up introduced, can be overridden.
*no A FLOOR in alternate law.
How do pitch and roll change in alternate law?
Pitch control identical to normal law.
Roll control is conventional (proportion to side stick) and no bank protection.
How do pitch and roll change in alternate law?
Pitch control identical to normal law.
Roll control is conventional (proportion to side stick) and no bank protection.
How does yaw control change in alternate law?
No automatic turn coordination- must use rudder pedals.
In most cases yaw damping remains functional.
What protection remains in alternate law?
Load factor limitation remains.
All other protection lost, replaced by high and low speed stability.
When does alternate law change to direct law for landing?
When gear is extended- flare mode.
