Communication, Light Signals, and Runway Lighting Systems practice questions

Answer: C) It blocks or distorts the radar signal

• AIncorrect. The issue is signal blocking.
• BIncorrect. The concern is signal transmission.
• CCorrect. Radomes must be transparent to radar energy.
• DIncorrect. Only approved non-metallic coatings are used.

Answer: A) White

• ACorrect. Wingtip strobes are white; beacons are often red.
• BIncorrect. Green is the right position light.
• CIncorrect. Blue is not used for anticollision lights.
• DIncorrect. Amber is not a standard strobe color.

Answer: A) About 108–118 MHz

• ACorrect. VORs operate between about 108.0 and 117.95 MHz.
• BIncorrect. This is not the VOR band.
• CIncorrect. That is AM broadcast.
• DIncorrect. That is the ELT frequency.

Answer: A) Immersion in water, which activates the beacon's water-sensing switch

The underwater locating device on a flight recorder is a self-powered acoustic beacon that turns on automatically when it is immersed in water. Current TSO-C121b units must keep transmitting for at least 90 days.

• ACorrect. The recorder's acoustic beacon is water-activated. Once it is submerged it sends out ultrasonic pulses so searchers can find the recorder underwater. Units built to TSO-C121b must operate for at least 90 days. The older TSO-C121/C121a standard required 30 days.
• BIncorrect. A G-switch is how an emergency locator transmitter (ELT) is activated, not the recorder's acoustic beacon. The beacon starts only when it is immersed in water.
• CIncorrect. The beacon runs on its own battery, and losing aircraft power does not start it. Water immersion starts it.
• DIncorrect. The beacon needs no action from the crew. It turns on automatically when submerged, so it works even if the crew cannot act.

Answer: C) It needs a clear view of the sky

• AIncorrect. Temperature is not the reason.
• BIncorrect. Location is for signal reception.
• CCorrect. The fuselage can block signals from below.
• DIncorrect. Signals come from satellites.

Answer: A) To minimize RF coupling and interference between the aircraft's radio systems

Antennas are kept apart, as far as practical from other radiating antennas, to limit RF coupling and interference between radio systems. Manufacturer instructions give system-specific limits.

• ACorrect. FAA guidance says to place antennas as far as possible from other radiating antennas and interference sources, because closely spaced antennas can couple and interfere with each other.
• BIncorrect. Antennas do add a little drag, but the minimum separation guidance exists to control electromagnetic interference, not aerodynamic effects.
• CIncorrect. Antenna weight is accounted for in the weight and balance records. It is not the reason for antenna-to-antenna spacing.
• DIncorrect. Lightning protection relies on bonding and protective devices. Separation distances are set to limit RF interference between systems.

Answer: A) Green

• ACorrect. The right wingtip shows green.
• BIncorrect. Red is on the left wingtip.
• CIncorrect. White is the aft position light.
• DIncorrect. Amber is not a standard position light color.

Answer: B) A reinforcing doubler under the skin

Mounting an antenna on thin skin usually requires a reinforcing doubler, matched to the skin, to restore strength and carry air loads. Gaskets, static wicks and balance weights do not provide that reinforcement.

• AIncorrect. Balance weights are used to mass-balance control surfaces. They do not reinforce skin or carry antenna loads.
• BCorrect. A doubler reinforces the skin at the antenna mounting point. It should match the existing skin in thickness, material and strength.
• CIncorrect. A gasket seals the base and can make up for slight skin curvature, but it adds no structural strength.
• DIncorrect. Static wicks bleed off static charge, usually from trailing edges. They do not strengthen the skin.

Answer: A) To guide passengers along the aisle to the exits when lighting more than 4 feet above the aisle is obscured

Under 14 CFR 25.812(e), the escape path marking guides passengers along the aisle to the exits when smoke hides all lighting more than 4 feet above the floor. Passengers can find each exit using markings that are no higher than 4 feet.

• ACorrect. Section 25.812(e) requires the marking to provide evacuation guidance when all sources of light more than 4 feet above the cabin aisle floor are totally obscured, as they would be by smoke. Passengers must be able to follow the path to the exits using only markings no higher than 4 feet.
• BIncorrect. Lighting outside the exits and on the escape slides comes from the separate exterior emergency lighting requirements, not the interior escape path marking.
• CIncorrect. The escape path marking is part of the emergency lighting system for evacuation guidance. It is not normal cabin lighting.
• DIncorrect. Slide-arming status is shown by door indicators and flight deck annunciations. The escape path marking guides passengers, not the crew.

Answer: A) Cleared for takeoff

• ACorrect. Steady green to an aircraft on the ground means cleared for takeoff.
• BIncorrect. That is steady red.
• CIncorrect. That is flashing white.
• DIncorrect. That is flashing red.