Flashcards in Flight controls Deck (12):
What's an ACE? How many do we have?
• Actuator Control Electronics: Unit that connects the control column electronically to the respective control surface, providing direct analog control of the surface.
1. P-ACE primary
2. SF-ACE slat/flap
3. H-ACE horizontal
4. S-ACE spoiler
What's a FCM? How many do we have?
• Flight Control Module: Software based assistance connected to the P-ACE providing digital inputs and is required for normal-mode operation of flight control system. Provides high-level functions
• 4 FCMs : broken into 2
What high-level functions are provided by the FCM?
1. Control laws scheduling with airspeed
2. Auto-thrust compensation w/elevator
3. AoA limiting
4. Rudder airspeed gain
5. Yaw damper and turn coordination
6. Rudder authority
7. Roll spoiler scheduling w/ speed and speed brake deployment
8. Configuration change compensation with high speed due to speed brake actuation.
What is Direct mode?
• Removes the FCM (high level functions) from the control loop and control limits default to the value set by the hardware in the P-ACE.
What systems provides data to the flight control system?
1. Smart probes and Air Data Application modules (ADA): provide air data for airspeed argumentation commands
2. IRS: provides attitude and accelerations to the FCMs for AoA function computation
3. PSEM: provides WoW and ground spoiler position data
4. BCM Brake Control Module: provides wheel speed signals for ground spoiler deployment
5. FADEC: provides thrust lever angle to FCM for thrust level compensation and AFCS provides autopilot commands
6. EICAS: data shared to display warnings. cautions, advisory, and system status.
How long do the Fly By Wire backup batteries last?
- 15 min
- No dedicated message to indicate failure
- charged by DC ESS 3
What is a PCU? How many?
• Power Control Unit: receives FCM compensated data from the P-ACE and directly actuates the control surface
1. Hyd Sys 1: left outboard
2. Hyd Sys 2: left and right inboard
3. Hyd Sys 3: right outboard
What is the Stabilizer Trim priority logic?
4. FCM (auto-trim) commands
Any flight control concerns during an electrical emergency?
1. Trim works at half speed (manual or Auto)
2. Horizontal stabilizer moves at a low rate
When will the ground spoiler surfaces deploy?
2. Wheel speed 45kt / Airspeed >60kts
3. TLA below 26º
What is a FLT CTRL BIT EXPIRED message?
PBIT time expired: Test must be Re-run.