Advanced Systems

Question 1

What does EFIS stand for

Answer 1

Electronic flight instrument system

Question 2

What are the components of a EFIS display

Answer 2

Primary Flying Display
•Multi-function Display (MFD)
•Controls for both typically located around the edges of the display

•Standby instruments may be via a further electronic unit, be electronically spun gyroscopes, or be more traditional suction driven gyroscopes

Question 3

Describe the function of Air Data Computer and Signal generator.

Answer 3

Air Data Computer - gathers static air temperature, static and pitot pressures, angle of attack, and calculates the airspeed, altitude, vertical speed and so on.

Signal Generator - using the information from the ADC, it produces the necessary and graphics to display to the pilot.

Question 4

Describe the function of input data sources to a basic glass flight display system (magnetometer, accelerometer and MEMS)

Answer 4

Magnetometer - use to measure magnetic field strength for orientation

Accelerometer - measures acceleration focus acting on an object to determine the objects position in space and monitor movement

MEMS, micro electronic mechanical switches - sense change in velocity.

Question 5

Describe the components and operation of an Attitude Heading Reference System (AHRS

Answer 5

Solid state three-axis system which provide heading, attitude and yaw to aircraft and replace gyroscopic instruments.

these use MEMS, accelerometers and magnetometers, Some units have the capacity to display GNSS data

Question 6

Describe the management of EFIS system failures. (3 Failures)

Answer 6

Electrical - reduce load, most systems will automatically turn MFD off if alternator fails

Icing - should be dealt with as the same for non EFIS aircraft. Blockage or leak will register the same as it would for non-EFIS

Equipment failure - little to be done, use backup instruments and land.

Question 7

What does the PFD present?

Answer 7

Airspeed, Atittude, slip bar, Vertical speed, horizontal speed

Question 8

Describe the function and operation of a typical TCAS system.

Answer 8

Designed to reduce the incidence of mid air collisions.

Searches for other transponders nearby
The transponders ‘talk’ to each other to determine if aircraft are going to come too close to one another

Warns pilots if this may occur and is Independent of Air Traffic Services. Depending on the type of TCAS equipment installed, it may offer a Resolution Advisory (RA)

Question 9

Who’s required to use a TCAS and what are some characteristics about it regarding to how they work

Answer 9

Mandated by ICAO for all aircraft over 5700kg, or who can carry more than 19 passengers

•The transponders may interrogate each other several times a second, Each TCAS system builds a 3 dimensional view of the airspace around it. Need a correctly operating mode C or S (or ADSB)transponder

Question 10

What are the TCAS 1 characteristics (4)

Answer 10

Cheaper and mainly used in General Aviation
•Is able to show another aircraft to within 40nm
•Will only warn the pilot about the other traffic (if needed)
•Will not give any Resolution Advisory (RA)

Question 11

What are the TCAS 2 characteristics

Answer 11

Used in airliners

•Has the same functions as TCAS 1, however, also gives a RA to climb or descend

Question 12

What are the TCAS 3 characteristics

Answer 12

The same as TCAS 2
•As well as an RA to climb or descend, it will advise a turn left or right in order to avoid other traffic

•If both aircraft have this, the system should coordinate these instructions to increase distance between the two aircraft

Question 13

Describe the function and operation of a typical GPWS system. (Ground proximity warning system)

Answer 13

radar altimeter fed information to a computer, If the rate of descent is too high, and the aircraft was near the ground, an audible alert sounded
•“Whoop whoop, Pull up, Pull up”

•However, the radar altimeter could only see directly below the aircraft, which limited its effectiveness

Question 14

What does TAWS stand for?

Answer 14

Terrain Avoidance and Warning System

Question 15

What are the 3 classes of TAWS and their characteristics

Answer 15

Class A

Excessive closure rate to terrain alert
•Flight into terrain when not in landing configuration alert
•Excessive downward deviation from an ILS glideslope alert
•Terrain awareness display that shows either the surrounding terrain or obstacles relative to the airplane, or both

Class B
Same as A but no requirement for visual display

Class C
Mostly for GA and designed for more voluntary usage

Question 16

What does FD-AFCS stand for?

Answer 16

Flight director, Automatic flight control system

Question 17

Describe the function of a basic FD-AFCS system.

Answer 17

It is the auto pilot system for aircraft.

Question 18

Describe the two systems and operation of a basic FD-AFCS system.

Answer 18

Single axis system – Roll only
•This will allow the wings to be kept level and a heading to be maintained by the autopilot

Two axis system – Roll and Pitch
•This allows altitude and heading to be maintained

They compare actual response with the demand and generate correcting control demand. Signal control actuators moves control surface and then monitor compliance with feedback..

Question 19

Describe the typical:

(a) vertical operational modes

Answer 19

Autopilot systems which control a pitch axis can hold an altitude, or hold a rate of climb or descent

These may be used in conjunction with the lateral (across the ground) mode, so the aircraft is able to fly a profile on autopilot

Question 20

Describe the typical:

(b) lateral operational modes.

Answer 20

Lateral navigation is navigation over the ground (or water)

•When commanded, the autopilot will turn the aircraft to the next heading selected (typically by the Horizontal Situation Indicator (HSI) on a smaller aircraft), or via a navigation beacon or GPS

Question 21

With regard to the operation of a FD-AFCS system, explain the:

(a) limitations;
(b) cautions.

Answer 21

(A) turned off during takeoff and landing and tested according to a schedule. Max and minimum speeds may apply

(B) system still needs monitoring, an aid to help fly not replace the pilot.

Question 22

Describe the principle of a Global Navigation Satellite System (GNSS).

Answer 22

Encompasses all types of satellite navigation and is split into 3 segments. Space (satellites) Control (ground based stations) and User (receiver).

Stations feed information back to the master control station.

Question 23

How does GNSS work

Answer 23

Using trilateration. Process of finding out where you are by measuring distances with spheres. Works on time and the known position of GNSS satellites.

Satellite sends continuous signal consisting of a pseudorandom code that identifies the satellite, the time of transmission of the code and the satellite position at that time.

Question 24

How many satellites are required for GNSS?

Answer 24

3 for position and 4 for position and altitude.

Question 25

What is satellite clock and ephermeris error.

Answer 25

Satellite - Satellite clocks do drift, so need correcting. If the receiver obtains the wrong clock time, the calculated position will be incorrect

Ephermeris - Essentially position error. If the satellite erroneously reports its position, the receiver will incorrectly calculate its position

Question 26

What is ionospheric delay, multipath effect and receiver error?

Answer 26

Ionospheric - Where the speed of the satellite signal is affected by the ionosphere

Multipath - Where satellite signals reflect off buildings and terrain. This causes a signal to be received at the wrong time.

Receiver - Includes any issue with the receiver, including placement of the aerial

Question 27

What can interference of satellites do to GNSS?

Answer 27

There are four bands (a grouping of frequencies) that GNSS satellites transmit on, and they have a weak signal strength, interference can block or make signals weak or stop.

Question 28

What is Geometric Dilution of Position?

Answer 28

Where the calculated position may have a larger degree of uncertainty due to the location of the satellites

•The closer the satellites are together, the greater the error factor

Question 29

What does RAIM stand for?

Answer 29

Receiver Autonomous Integrity Monitoring.

Question 30

Explain the term RAIM prediction and the significance of these predictions.

Answer 30

RAIM predictions dictate if you can carry out a GPS approach,If there is a RAIM hole (or RAIM outage) predicted in the area of your destination at your ETA, you will need to change your plan

•Similarly, if you are about to commence a GPS approach, you may not do so if you receive a RAIM warning.

Question 31

What is the principle of operation of RAIM?

Answer 31

There’s no way for a receiver to know if the information broadcast by a satellite is correct, but the receiver can compare its position given by a number of satellites and if one is substantially different, it is likely wrong and can be ignored

If receiver detects an issue with satellite data, it’ll display a RAIM warning.

Question 32

How many satellites are required for RAIM?

Answer 32

Minimum of 5, but requires a minimum of 6 incase one stops. If theres less its known as a RAIM hole.

Question 33

What does RNP stand for?

Answer 33

Required navigation performance

Question 34

What is PBN?

Answer 34

Performance Based Navigation

•PBN is the basis for defining system performance requirements for navigation equipment and installations

Question 35

What is RNP reference too?

Answer 35

RNP refers to the level of performance required for a specific procedure (usually an approach to an airport) the smaller the number the more accurate the approach must be and is given in nautical miles.

•RNP will have a number associated with it, eg: RNP 3

Question 36

What would RNP 3 mean?

Answer 36

RNP 3 means that the aircraft navigation system must be able to calculate its position to within a radius of 3 nautical miles

Question 37

What are the requirements for RNP? (4)

Answer 37

• To fly an RNP approach, aircraft need to have
• GNSS system and back up
• Performance monitoring
• An alerting system in the event of failure

Question 38

What are the advantages of RNP? (5)

Answer 38

Greater navigational accuracy
•Reduces step-down and circling approaches
•Saves fuel and time
•Increases airspace capacity
•Reduces missed approaches