Flight controls Flashcards
How many channels FBW has?
3 channels, Any of the three FBW channels can allow safe flight and landing.
What are Inceptor Interface Modules (IIMs),
The FBW system includes three IIMs. The IIMs receive data from the flight deck controls and transmit it to the PFCCs. Each IIM is connected to the three PFCCs.
How many PFCCs are there and which one is control?
3 PFCCs, only one is in control of FBW system, it is determined automatically during startup
What is function of REUs?
Transmit commands from PFCCs to hydraulic PCUs and to stabilizer trim motors
What is the AFCU
Alternate Flight Control Unit, bypasses the REUs if there is a severe FBW system degradation
Explain REU direct mode?
PFCUs recieve inputs from IIMs and REUs skipping PFCCs. It is REU DIRECT MODE
What is provided by Fly-by-wire Normal mode?
Envelope protection, structural envelope protection, ground mode functions
Explain nose gear loading function of the FBW system
With the sidestick at the neutral position (no pilot input), the elevator is automatically set to 12 degrees nose down up to 80 kt and decreases to 0 degrees by 90 kt.
Normal mode ground mode functions?
- Direct, full travel authority of the elevator,
- Pitch rate damping,
- Direct control of the horizontal stabilizer trim,
- Nose-up pitch attitude limit set to 17 degrees,
- Sidestick shaker function above 60 kt, and
- Yaw damper function enabled at 70 kt
What is pitch limit on ground in normal mode between 60 and 90kt?
Reducing from 12 to 0 degrees
At what altitudes is bank limited to half bank?
31500ft
What is maximum roll and bank provided by engine-out compensation function from Fly-by-wire?
5 deg yaw, 20 deg bank
Is engine out protection function working on ground?
NO
Wht types of direct modes are there?
Dependent on the type of failure, the system reverts to one of three types
of direct mode:
* Primary Flight Control Computer (PFCC) direct mode,
* Remote Electronics Unit (REU) direct mode, or
* Alternate Flight Control Unit (AFCU) direct mode.
What is PFCC direct mode?
The PFCC direct mode is used when the information required for normal mode is degraded or not received by the PFCCs
What are the 2 PFCC direct sub modes?
- When PFCC direct mode occurs because there of data input failure from all Air Data Smart Probes (ADSP), the FLT CTRL DIRECT ADS
caution message is displayed on the EICAS page. - When PFCC direct mode occurs because there is an input failure of all inertial data, the FLT CTRL DIRECT IRS caution message is
displayed on the EICAS page.