Card Set Information
170 190 Landing Gear Brakes
E-170/190 Landing Gear and Brakes
What type of landing gear is installed?
Retractable tricycle landing gear
How is the landing gear extended and retracted?
Electrically commanded, hydraulically actuated
In a 180
turn on the ground, will the tail clear if the wingtip does?
How many sensors are there for each gear?
2 uplock and 2 downlock sensors for each
Can you monitor the brake pressure and brake temperature?
Yes, on the MFD Status page
When will the aural wanring for the landing gear sound?
If the gear is not down and locked, and
- <700 RA, TLA below 45
(2 engines) or below 59
(1 engine), and Flaps 0-4, or,
- Any altitude with flaps set 5 or more
- Dual radio altimeter failure
How long would you expect to have to wait after lowering the gear handle to see a RED icon indicating a discrepancy between a gear position and the LG lever position?
20 seconds after the discrepancy is detected
When is the LG WRN INHIB switch used?
To inhibit the landing gear warning in the event of a dual radio altimeter failure
What will cause LG WRN INHIB system to reset allowing a new warning activation?
The flap selector is set to 5 or FULL positions without any landing gear down and locked, or
TLA over 45
(2 engines) or 59
What are the three landing gear extension modes?
Normal - LG lever down
Electrical Override - Bypasses PSEM to directly command selector valve
Alternate Gear Extension - Manual uplock release opens free-fall sequencing valve
What is the purpose of the DN LOCK RLS button on the landing gear lever?
Mechanically releases the landing gear lever lock
Lock protects against inadvertent landing gear retraction when WOW
When would you use the Electrical Override switch?
When the normal extension mode fails, the electrcial override system bypasses the electric proximity switches and opens the gear doors and lowers the landing gear
How do you lower the gear if you lose all hydraulics?
Alternate gear extension handle
When would you use the Alternate Gear extension procedure?
In the event of a failure of the electric and hydraulic systems
When the alternate gear extension lever is pulled, it does what?
It relieves hydraulic pressure in the landing gear lines and releases all landing gear uplocks. The gear falls down by gravity.
After using the alternate gear extension system, can you restore normal gear operation?
Yes, by placing the alt gear lever back in it's initial position
What keeps the gear locked in position?
: Downlock springs
: Uplock hooks
How do the landing gear doors actuate?
Mechanically, during landing gear extension or retraction
How are the brakes commanded?
Electrically commanded, hydrualically actuated
Pedal position transducers send brake requests to the BCM (Brake Control Module)
What hydraulic systems provide brake pressure?
HYD 1 - Outboard brakes
HYD 2 - Inboard brakes
HYD 1 & 2 - Parking/Emergency brake
What is touchdown protection?
No braking until 3 seconds or > 50 kts wheelspeed after touchdown
Describe Anti-skid protection.
Compares wheel speeds and releases pressure (deactivated below 10 kts)
Describe Locked-wheel protection.
Allows up to 30% differential braking for steering purposes (deactivated below 30 kts)
How many applications will the parking/emergency brake provide?
6 applications or 24 hours as a parking brake
Does the nose gear landing light and taxi light automatically extinguish with gear retraction?
Anti-skid protection is not available for which system?
Emergency/parking brake system
What stops the wheels from spinning during retraction?
Main gear - BCM applies brakes after weight-off-wheels
Nose gear - Snubbers in the nose bay stop the wheels
What disengages the rudder pedal steering?
The activation of the nosewheel steering
When is the free wheel steering mode activated?
When the steering angle is greater than 76
or there is a system failure
What must be done to switch to free wheel steering mode?
Push the steering disengage switch
When the steering disengage switch is activated, disengaging the noewheel steering system, how is the system re-engaged?
Steering handle must be momentarily pushed down
Which hydraulic system controls the nosewheel steering?
How far does the nosewheel turn (max) in either direction?
but is reduced as speed increases
What is the maximum nosehweel steering angle using the rudder pedals?
+/- 7 degrees
Does the tiller work on takeoff roll?
Yes, but authority is decreased as a function of speed. Up to 76
under 40 kts, and then decreases to 7
to 100 kts.
Is there ever a time when freewheel steering is automatically selected?
Yes, when steering angle is more than 76
failure of the WOW sensor
steering system failure
How can the towing lights on the nosewheel be tested?
With a test switch on the back of the lights
How does the ground crew know that the nosewheel is disengaged and towing is allowed?
There is a green towing permissable light on the nosewheel. The RED towing is not permissable light will illuminate when the nosewheel steering is not disengaged.
How many emergency/parking brakes do we have?
What are the limits for the nosewheel steering?
Angle varies with ground speed
Up to 40 kts
41 to 100 kts
: Decreases linearly from 76
If the parking brake is used for landing instead of the main foot brakes, is there any anti-skid protection?