Laws Flashcards
Flight Mode
of
Normal Law
Load Factor Demand in Pitch, all protections available
Load Factor Demand
Normal Law - Pitch
A specific input results in the same G change regardless of the current airspeed
Automatic Pitch Trim
Normal Law - Pitch
If the desired pitch attitude requires the elevators to remain displaced, THS movement is commanded until the elevators are centered with the THS.
Manual Pitch Trim Not Required
Ground Mode
of
Normal Law
(Normal Law - Pitch)
Direct stick to flight control relationship
Enables pilot to:
- Check Controls
- Rotate A/C for takeoff
Lost in Alternate Law
Landing Mode of Normal Law
Normal Law - Pitch
Created to give the flare and touchdown a “conventional feel”
- 50’ AGL - ELACs memorize pitch attitude
- 30’ AGL - ELACs add a gentle nose down command which the pilot counters with an aft stick input.
Lost in Alternate Law
Maneuver Protection
Normal Law - Pitch
Prevents flight control surface movement that would cause the aircraft to exceed preset G limits.
Prevents aircraft damage due to over stressing the aircraft
Pitch Protection
Normal Law - Pitch
30 degrees nose up
15 degrees nose down
Lost in Alternate Law
High Speed Protection
Normal Law - Pitch
Prevents A/C damage due to excessive speed
Activates just above VMO/MMO
Gentle pitch up is produced to limit acceleration
Acceleration limited even if full forward stick applied
Automatic pitch trim nose down deactivated
AP deactivates
Always possible to overspeed, flight computers merely limit max attainable speed to within safe limits.
Alpha Prot
Normal Law - Pitch
AOA where computers intervene to prevent alpha from reaching a stall alpha
- Logic changes from load factor demand to commanding an angle of attack
- Addt’l nose up trim inhibited, nose down available
- AP disengages
- Lowering of pitch attitude occurs
Note: Actual angles of attack that correspond with Alpha Protection and Alpha Max are computed by the ELACs based on AOA, not airspeed.
Alpha Max
Normal Law - Pitch
Highest AOA that ELACs will allow
Lower alpha than ALPHA STALL; therefore, it is nearly impossible to stall the aircraft in normal law
Note: Actual angles of attack that correspond with Alpha Protection and Alpha Max are computed by the ELACs based on AOA, not airspeed.
Alpha Floor
Normal Law - Pitch
- Predictive function of the A/THR system
- Activates based on current trend if it predicts thrust will be required
- Available rom immediately after TO throughout the flight down to 100’ RA in config 1 or greater.
- Only available in Normal Law
Uses A/THR system to automatically provide TOGA if any of the following occur:
- Excessive high angle of attack
- Indirectly as a result of windshear
- Excessive nose up attitudes combined w/specific side stick inputs
Predictive, triggered at any airspeed, not depicted on airspeed tape. Can be at airspeeds significantly higher than Alpha Prot
- TOGA thrust automatically applied regardless of lever position
- DOES NOT require A/THR to be engaged, just available
Roll Rate
Normal Law - Roll
Neutral stick - Requests zero roll rate (maintains current bank angle)
Full stick deflection - Request 15 degrees/sec roll rate
Stick slightly left/right of center - Requests between 15 and 0 degrees/sec roll rate
Lost in Alternate Law
Pitch Trim < or equal to 33 degrees
Normal Law - Roll
Automatic pitch trim available up to 33 degrees of bank
Bank Angle Hold < or equal to 33 degrees
Normal Law - Roll
If stick released to neutral, a 0 degree/sec roll rate is commanded
A/C maintains a constant bank angle, unless commanded otherwise
Lost in Alternate Law
Positive Spiral Stability
Normal Law - Roll
If bank angle exceeds 33 degrees and stick is released, bank angle returns to 33 degrees.
Returns bank angle to 0 degrees if high speed protection is active.
Lost in Alternate Law
