Flight Augmentation

Question 1

Four functions of FAC

Which two computers does it talk to?

Answer 1

• Yaw
  
  • YD, turn co-ord
  • Rudder trim
  • Rudder limiter
• Flight Envelope
  
  • PFD speed computation
  • Alpha floor
• Low Energy Aural Alert
• Windshear Detection

Talks to ELAC / FMGC

Question 2

Speeds that FAC calculates

Answer 2

• VSW
• VLS
• VFE / Next
• VLE
• VMO/MMO
• Green dot, S, F speed
  Also calculates trend arrow

Question 3

What weight data does FAC use?

FAC calculates VS1G from AoA / GW either side of what alt / speed?

Answer 3

Continuously calculates speeds based on FMS gross weight
* Also calculates its own GW/CG
* ELAC and FMS crosschecks with this
* Also for back up with dual FMS failure
* VS1G calculation
* from AoA under 14600 ft + 250 kt
* FROM GW over 14600 ft OR 250 kt

Question 4

When is Alpha Floor inhibited?

Answer 4

• OEI and slats/flaps
• EIU fail
• SFCC/FMGC failures
• Dual FCU
• Dual FMGC
• Altn/dir law
• A/THR locked out

Question 5

When is Low Energy Aural Alert (SPEED SPEED) active?

Answer 5

Config 2/3/Full only
Considers
* Decel rate
* FPA

Question 6

When is windshear detection active?

What is it predicting, what data does it use?

Answer 6

• 3 sec after lift off to 1300 RA
• 1300 RA down to 50 RA
• Config 1 min
  Prediction
• Predicted energy level falls below a threshold
• ADIRS data inc: VS, longitudinal wind gradient, vertical wind
• FAC expesses the energy level as an AoA