Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ASA General and Airframe Oral > Communication and Navigation Systems > Flashcards

Communication and Navigation Systems Flashcards

1
Q

Which frequency band is used for long-range communications from an aircraft?

A

The high frequency band (2 to 25 megahertz)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the two methods of modulating carrier waves for transmitting information?

A

Amplitude modulation (AM) and frequency modulation (FM).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is meant by a transceiver?

A

It is a piece of radio communications equipment in which all of the circuits for the receiver and transmitter are contained in one housing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Is a certificated airframe mechanic allowed to adjust a communications transmitter?

A

No, this requires a license issued by the Federal communications commission.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What kind of antenna is ued for the ATC transponder?

A

A UHF stub antenna.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the preferred location for the ATC transponder atenna?

A

On the center line of the belly of the aircraft as far from any other antenna as is practical.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the three basic types of antennas used in aviation?

A

Dipole antenna, Marconi antenna, and loop antenna.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What type of antenna are most aircraft VHF communication antennas?

A

Marconi antennas.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do static wicks aid the aircraft communication radios?

A

Static wicks aid in the dissipation of static that builds up on the aircraft. Built-up static can cause radio receiver interference caused by corona discharge emitted from the aircraft as a result of precipitation static.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the purpose of an intercom system?

A

To aid in communication between the flight crew, or between the flight crew and the cabin crew.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What kind of conductor is used to connect a VHF or UHF antenna to the receiver or transmitter?

A

coaxial cable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a coaxial cable?

A

A type of two-conductor electrical cable in which the center conductor is encased in insulation inside a braided shield that serves as the outer conductor. Coaxial cables are normally used for attaching radio receivers and transmitters to antennas.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How can you determine the proper coaxial cable and connectors to use in an aircraft radio installation?

A

Refer to the radio installation instructions for the correct part number for the cable and connectors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What precautions should be taken when installing coaxial cable between a radio transmitter and its antenna?

A

The routing should be as direct as possible, there should be no sharp bends in the coax, and it should be kept away from heat that could soften the insulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a BNC connector?

A

A coaxial cable connector that is connected by inserting the guide pins on the male connector into slots in the female connector and twisting the connector one quarter turn.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What kind of antenna is used for VHF communications?

A

A vertically polarized whip antenna.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which frequency band is used for most aircraft communications?

A

The VHF band, between 30 and 300 megahertz.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the Aircraft Communications Addressing and Reporting System (ACARS), and how does it work?

A

ACARS is a two-way communication link between an airliner in flight and the airline’s main ground facilities. Data is collected in the aircraft by digital sensors and is transmitted to the ground facilities. Replies from the ground may be printed out so the appropriate flight crewmember can have a hard copy of the response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

On what two frequencies does the emergency locator transmitter operate?

A

121.5 and 243.0 megahertz.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where is the ELT transmitter normally located on an aircraft?

A

In the tail of the aircraft or as far aft as possible, so it will be least likely to be damage in the crash.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How often should the ELT batteries be replaced or recharged?

A

When the transmitter has been in use for more than 1 cumulative hour, when the battery expiration date has been reached, or when 50% of their useful life or charge has expired.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How can you know when an ELT battery must be replaced or recharged?

A

By the date marked on the outside of the transmitter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How often must ELTs be inspected for proper installation, battery corrosion, operation of the controls and sensor, and the presence of the radiated signal?

A

Every 12calendar months.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What causes an ELT to actuate?

A

An inertia switch that detects an impact parallel to the longitudinal axis of the aircraft as would occur in a crash.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How is an ELT tested to determine that it is working?

A

Actuate the test switch and listen on 121.5 or 243.0 MHz. Make the test during the first five minutes of the hour and do not allow the ELT to operate for more than 3 sweeps. If the ELT is operated outside of this time frame, you should contact the control tower before conducting the test.

26
Q

What two types of antenna are used with most ADF receivers?

A

A directional loop antenna and a nondirectional sense antenna.

27
Q

Why is it necessary to install a doubler on the inside of the aircraft skin when antenna is mounted on the skin?

A

The doubler reinforces the skin so wind loads on the antenna will not cause the skin to flex and crack.

28
Q

What is the preferred location for a VOR antenna on an airplane?

A

On top of the aircraft, along the center line of the fuselage.

29
Q

Which component of the Instrument Landing System shares the antenna with the VOR?

A

The ILS localizer.

30
Q

In which frequency band does the VOR equipment operate?

A

In the VHF band, between 108.0 and 117.98 MHz.

31
Q

What is the preferred location for a DME antenna?

A

Along the center line of the belly of the aircraft, as far rom any other antenna as is pratical.

32
Q

In what frequency band does the DME equipment operate?

A

In the UHF band, between 962 and 1,024 MHz, and between 1,115 and 1,213 MHZ.

33
Q

What does the DME system measure?

A

Direct distance to the station that the signal is received from.

34
Q

What two signals are transmitted from an ILS ground-based station and then received in the aircraft?

A

A localizer signal provides horizontal guidance to the centerline of the runway. A separate glideslope provides vertical guidance of the aircraft down the proper slope to the touchdown point on the runway.

35
Q

Where do GPS units receive their signal from?

A

From satellites that orbit around the earth.

36
Q

How many satellites are typically in view of a GPS receiver?

A

Between five and eight satellites.

37
Q

How does a GPS receiver determine its position?

A

The amount of time it takes for signals to reach the aircraft GPS receiver from transmitting satellites is combined with each satellite’s exact location to calculate the position of an aircraft.

38
Q

What aircraft system does TCAS (traffic collision avoidance system) use for air-to-air monitoring and alerting?

A

The aircraft transponder.

39
Q

What is a TCAS Resolution Advisory (RA)?

A

This is an aural command to the pilot to take a specific evasive action (i.e., DESCEND). The computer is programmed such that the pilot in the encroaching aircraft receives an RA for evasive action in the opposite direction (if it is TCAS equipped).

40
Q

What type of weather is shown by an onboard weather radar system?

A

Onboard weather radar signals bounce off of precipitation only. Clouds do not create a return.

41
Q

Weather aids referred to as weather radar cover what three types of systems?

A

Onboard weather radar, lightning detectors, and satellite or other source weather radar information that comes from an outside source.

42
Q

What is the primary advisory that a radio altimeter is used for?

A

The landing decision height when on an instrument approach.

43
Q

Where does a ground proximity warning system receive its information from?

A

From a radio altimeter.

44
Q

What is the basic purpose of an autopilot?

A

It frees the human pilot from continuously having to fly the aircraft, and flies with a high degree of precision. It also couples with various electronic navigation aids.

45
Q

What are the basic subsystems of an automatic flight control system?

A

Command
Error-sensing
correction
Follow-up

46
Q

What type of device is normally used in the error-sensing subsystem?

A

Gyros.

47
Q

What are three types of servos that are used in the correction subsystem?

A

Hydraulic, pneumatic, and electric.

48
Q

What is the purpose of the follow-up subsystem in an autopilot?

A

It stops the control movement when the surface has deflected the proper amount for the signal sent by the error sensor.

49
Q

What are the two parameters that auto-throttles can maintain or attain, and how do they function?

A

The two parameters are speed mode and thrust mode. In speed mode, the throttle is positioned to maintain a set target speed. In thrust mode, the engines are maintained at a fixed power setting to meet the different phases of flight (takeoff, climb, descent, etc.).

50
Q

What are the two types of helicopter stability augmentation systems?

A

A force trim system holds the cyclic control in the position at which it was released.

A more advanced system uses electric actuators that make inputs to the hydraulic servos based on control commands from a computer that senses helicopter attitude.

51
Q

At what altitudes does a radio altimeter begin to measure aircraft height above the ground?

A

Below 2,500 ft.

52
Q

What data does an ADS-B Out system transmit?

A

Aircraft GPS location
Altitude
Velocity
Speed

53
Q

Where does an ADS-B Out system transmit its data to?

A

Ground-based stations and other aircraft.

54
Q

In addition to information on other aircraft, what other information is available on ADS-B In?

A

Weather text and graphics information, ATIS information, and NOTAMs.

55
Q

What is the purpose of a transponder?

A

A transponder provides positive identification and location of an aircraft on the radar screens of ATC.

56
Q

How does an altitude encoder interface with a transponder?

A

For aircraft equipped with an altitude encoder, the transponder also provides the pressure altitude of the aircraft to be displayed adjacent to the ATC on-screen blip that represents the aircraft.

57
Q

Why is it important to follow the recommended procedures for testing ELTs?

A

A signal from an ELT can trigger a search and rescue operation, or at the very least, an inquiry to find out where the signal is coming from. Testing inside a metal hangar does not prevent the ELT’s signal from being picked up by Cospas-Sarsat satellite system.

58
Q

What precautions should be considered when routing wire harnesses?

A

Wire harnesses need to be protected from chafing and from interfering with other systems, especially those that have movement (retractable landing gear, flight controls, etc.). The routing of wire bundles also needs to consider the environmental condition that will be encountered (heat, corrosive environments, moisture, etc.). Wire bundles also generate magnetic fields and should not be routed close to other equipment that is sensitive to magnetic interference.

59
Q

What risks are associated with mounting aircraft antennas?

A

Antennas must be able to withstand high air loads and require a mounting doubler to be installed on the aircraft skin. The location of the antenna must not interfere with other locations and must be mounted in an area where signals can be optimally transmitted and received. Antennas must be electrically matched to the receiver and transmitter that they serve.

60
Q

Why is it important for static discharge wicks to be mounted on the trailing edges of control surfaces, wing tips, and the vertical stabilizer?

A

It is important that static wicks discharge static at points a critical distance away from avionics antennas where there is little or no coupling of the static to cause interference or noise in the radios.

61
Q

What risks are associated with working on live electrical systems?

A

The risks of working on live electrical circuits include inadvertent shorting of a positive voltage to ground, which could cause damage to a component, or inadvertent activation of systems. Additionally, power systems can cause electrical shock and injury to personnel.

ASA General and Airframe Oral (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions