Explanations: Position and Warning Systems Flashcards
How do antiskid systems work?
They are mounted in the wheel hubs, and produce a signal whose frequency is proportional to the wheel rotational speed.
This signal is sent into a computer where its rate of frequency change is compared with an allowable rate of change. If the rate is too fast, it signals that a skid is impending.
What happens when an impending skid is detected?
A signal is sent to the skid control valve. The skid control valve relieves hydraulic pressure from the brake until the rate of deceleration for its wheel is no longer excessive.
Anti skid systems are electrohydraulic, meaning what?
an electrical signal is sent to actuate a hydraulic valve in the brake system.
What happens when the arming switch is placed in the ARMED position in a brake antiskid system?
It releases the brakes and initiates the locked-wheel protection circuit. The armed antiskid system will not allow the brakes to be applied until the weight of the aircraft is on the wheels and the wheels have reached a rotational speed of more than 15 to 20 mph.
This same switch allows the pilot to deactivate the system.
A takeoff warning indicator system does what when it senses something is not in the correct configuration?
If the elevator or stabilizer trim in the takeoff range,
speed brake (spoilers) handle in the 0 degree position,
steerable fuselage landing gear is centered,
wing flaps are at 10 degrees,
landing-edge flaps are extended.
when will a warning sound in the takeoff warning system?
When any of the monitored flight controls are not properly set for takeoff, when the thrust lever is advanced, a warning will sound.
An airspeed indicator is what?
a differential pressure gauge that measures the difference between ram (pitot) pressure and the static pressure surrounding the aircraft at any moment of the flight.
What is the angle-of-attack indicating system?
It consists of an airstream-direction detector mounted on the side of the fuselage and an indicator mounted in the instrument panel.
The airstream-direction detector contains a sensing element that measures the direction of the local airflow relative to the true angle of attack.
It makes this measurement by finding the angular difference between the direction of the local airflow and the fuselage reference plane.
What does the squat switch do when the aircraft is airborne?
it causes the antiskid control box to prevent fluid reaching the brakes.
The control surface indicating system indicates what about the trim tab?
Whether the trim tab is set properly for the existing flight condition.
When are reed type stall warning indicators actuated?
when the angle of attack is increased to the position at which there is a negative pressure at the pickup hole in the leading edge of the wing.
What is another name for the squat switch?
the landing gear safety switch, or the ground safety switch, which is usually located on one of the main landing-gear shock struts. It prevents the landing gear from retracting when the weight of the aircraft is on the landing gear.
Can the brakes be applied when the plane is in the air?
No, because the antiskid system has a provision that prevents the brakes from being applied until weight is on the landing gear.
What is a remote indicating system?
It provides feedback about the status of control surfaces and other mechanically actuated devices on aircraft.
What is an autosyn remote indicating system?
It utilizes the interaction between magnetic fields set up by electric current flow to position the indicator pointer
