Module 5: Digital Techniques and Electronic Instrument Systems

5.1 Electronic Instrument Systems

Course Overview 08 – 11/4: 5.1, 5.2 15 – 18/4: 5.3, 5.4 22 – 25/4: 5.5, 5.6

13 – 16/5: 5.7, 5.8 20 – 23/5: 5.9, 5.10 27 – 30/5: 5.11, 5.12

03 – 06/6: 5.13, 5.14 10 – 13/6: 5.15 17 – 20/6: Review 24 – 27/6: Review

01 – 04/7: Review 08 – 09/7: Review and Final Test 10/7: Exams

Aircraft Principal Axes

An aircraft in flight is free to rotate in three dimensions: roll, rotation about an axis running from nose to tail. pitch, nose up or down about an axis running from wing to wing. yaw, nose left or right about an axis running up and down.

Flight Control Surfaces An Aircraft Rolling:

Ailerons are used in pairs to control the aircraft in roll, or movement around the aircraft's longitudinal axis, which normally results in a change in heading.

Flight Control Surfaces An aircraft pitching:

An elevator is mounted on the trailing edge of the horizontal stabilizer on each side of the fin in the tail. They move up and down together.

When the pilot pulls the stick backward, the elevators go up. Raised elevators push down on the tail and cause the nose to pitch up

Pushing the stick forward causes the elevators to go down and the tail goes up.

Flight Control Surfaces An aircraft yaws: The rudder is

attached to the vertical stabilizer and allows the pilot to control the yaw. If the rudder is

turned left, the plain turns left along the yaw axis.

If the rudder is turns right, the plane turns right along the yaw axis.

Other flight control surfaces Flaps:

Used to increase the descend and uplift angle.

Decrease the safe speed at which the aircraft can fly.

Spoilers: Lower the descend speed. Assist the rolling.

Trim tap: Used to hold the aircraft in a certain

altitude. The pilot does not have to keep constant control to the elevator

Cessna Cockpit

The Six Primary Flight Instruments

Airspeed is measured in Knots (1 nautical mile / hour).

1 Knot = 1.852 Km/h

Airspeed Indicator (ASI)

The Six Primary Flight Instruments

Shows the orientation of the aircraft relatively to the earth’s horizon.

Also called “Artificial Horizon”.

Attitude Indicator (AI)

The Six Primary Flight Instruments

Displays altitude. Altitude is measured in

feet. 1 foot = 0.3m

Altimeter (ALT)

The Six Primary Flight Instruments

Information about the heading.

Older names: Directional Gyro,

Direction Indicator etc.

Heading Indicator (HI)

Airspeed indicator, attitude indicator, Altimeter and heading indicator form the “classic – T” configuration.

The Six Primary Flight Instruments

Indicates the rate of turn of the aircraft.

Shows turns in roll and yaw axis.

Turn Coordinator (T/C)

The Six Primary Flight Instruments

Displays ascend and descend rate in feet / min.

Typical maximum values in non-pressurized aircrafts: ascend: 700 fpm descend: 500 fpm

Vertical Speed Indicator (VSI)

Other Instruments

Flaps

VOR Indicators

Automatic Direction Finder (ADF)

Engine Indicators

Communi-cation and Navigation Radios

Autopilot

Throttle

Elevator Trim

Automatic Direction Finder (ADF)

Distance Measuring Equipment (DME)

Types of Navigation ADF Navigation (Automatic Direction Finder) VOR Navigation (VHF omnidirectional range) GPS Navigation (Global Positioning System)

ADF Navigation

Non-directional Beacons (NDB): Radio transmitters used as navigation aids.

Each NDB transmits a signal of a specific frequency.

NDBs

417.0 KHZ

386.0 KHZ

307.0KHZ

431.0KHZ

ADF Navigation The NDB frequency to which

we navigate is placed in the Automatic Direction Finder.

The direction to the NDB is indicated in the ADF indicator.

ADF navigation is the oldest way of navigation.

There are very few NDBs today.

Is affected by atmospheric conditions, rough terrain, electrical storms, etc.

VOR Navigation

VOR: Very High Frequency omnidirectional range.

Each VOR beacon transmits a signal of a specific frequency.

VOR

SAT: 109.6 MHz

ATV: 117.2 MHz

DDM: 114.6 MHz

PLH: 108.8 MHz

VOR Navigation

I place the VOR frequency on a NAV (NAV1 or NAV2).

I select from the Audio Control Panel the correct NAV.

VOR indicator shows the direction to the VOR beacon.

Communication Radio 1 (COM 1)Communication Radio 2 (COM 2)

Navigation Radio 1 (NAV 1)

Navigation Radio 2 (NAV 2)

Distance Measuring Equipment (DME)

VOR Indicator 1

VOR Indicator 2

Audio Control Panel

VOR Navigation Direction to VOR Beacon

The VOR frequency

Distance to VOR Beacon

Selector

Beacon Direction (The VOR beacon is behind the airplane FROM indication).

VOR Navigation How to find the correct

direction the VOR beacon? Turn the selector until

the needle is centered and the indication shows a “TO” indication.

Write down the Heading. To fly to the VOR

beacon, we must fly at 248 degrees.

So, we place the heading to the heading indicator.

“TO” indication

“TO” indication and needle is centered. Heading: 248o.

VOR Navigation

I fly at 248 degrees, trying to keep the needle of VOR 1 centered. If the needle, while I fly is placed left, then I should turn left, until it is

centered again. . If needle, while I fly is placed right, then I should turn right, until it is centered

again. The needle shows to which direction the pilot should fly, to reach the beacon.

I placed the heading indicated by VOR 1 to the Heading Indicator.

GPS Navigation

Route is loaded in the GPS.

We just follow the route.

The route

Current Heading

Target Heading

Distance to next waypoint

Time until next waypoint

Current airspeed

GPS Navigation Usually pilots do not rely explicitly in GPS for

navigation. They use a combination of FMC (flight

management computer), VOR and GPS to follow the planed route.

However, GPS is likely to replace VOR navigation in the near future.

The AutopilotAutopilot will follow NAV or GPS flight plan?

The autopilot

Engage / disengage the autopilot

Reach on maintain the heading displayed by the HI.

Follow the navigation plan of the selected NAV or GPS.

Reach or maintain the altitude as indicated in the autopilot.

The target altitude.

The maximum vertical speed to reach the target altitude. .

Types of approaches Visual approach. GPS approach (Global Positioning System). ILS approach (Instrument Landing System).

The Approach Before approaching the

airport the pilot is informed by the ATC about the runway he will land.

Then, he makes the approach flight path.

For example: We are approaching KJFK

(New York International Airport) and we are instructed to land to Runaway 31L. Runway 31L means the left

runway that is placed in 310o.

There are usually more than one ways to approach the runaway.

We select the one (with the help of the ATC) that better fits our inbound direction.

The Approach Each different approach to 18R

has a specific name, depending from the direction the pilot approaches the airport.

There are many ways to approach the runaway.

We select the one (with the help of the ATC) that fits us best.

The Landing

4 lights on the runway indicate if the plane follows the glidepath.

Altitude

The glidepath. The optimal descending route for landing.

The Landing

Before landing: Landing gears are extended. Flaps are fully extended. Throttle is off.

The aircraft moves parallel to the runway, until the rear landing gears touch the runway and finally the front.

Visual Approach We just follow ATC (Air Traffic Control)

instructions to approach the airport. The pilot must always have clear sight of the

airport. Can be only made in clear weather.

ILS Approach ILS: Instrument Landing System. Each runway that provides ILS

has a specific ILS frequency. The pilot, while approaching the

airport places the ILS frequency in the NAV.

Localizer indicates the correct position to land to the runway.

Glideslope indicates the correct altitude.

ILS Approach VOR indicator works

now as an ILS indicator.

The vertical needle shows the localizer position and the horizontal the glideslope position.

Both needles must always be vertical in order to move on the glidepath.

Am I left or right of the runway?

Is my altitude correct?

Airbus A320 cockpit layout

4 types of instruments: PFD, ND, E/WD, SD.

EIS = EFIS + ECAM

E.I.S.

E.F.I.S.

ECAM

EIS: Electronic Instrument System. EFIS: Electronic Flight Instrument System (Glass Cockpit). ECAM: Electronic Centralized Aircraft Monitor. 4 types of instruments: PFD, ND, E/WD, SD.

EFIS: PFD & ND PFD: Primary Flight Display

All information to fly the aircraft Attitude Indicator Airspeed indicator Altitude indicator Vertical speed Compass

ND: Navigation System Display All information to navigate the aircraft: Several Different Modes:

Heading Indicator VOR ILS TCAS (Traffic Collision Avoidance System)

EFIS: Failure Warnings

EFIS Failure flag are shown with a flashing red flags.

Warnings on PFD

ECAM: SD & E/WD E/WD: Engine/Warning

Display Engine indicators, fuel

quantity, flaps and slats position

Warning and caution messages

SD: System Display

ECAM ECAM: Electronic Centralized Aircraft Monitoring:

A system that monitors aircraft functions and relays them to the pilots.

Produces messages detailing failures and in certain cases, lists procedures to undertake to correct the problem.

It is managed by a central maintenance computer, which is provided with data from several systems and sensors.

ECAM Indications Aural Visual

Level 3 warning overspeed, fire, stall Repetitive chime

Red light flashing /

Level 2 warning system failure, but not direct consequence on flight safety

Single chime

Amber light

Level 1 warning failure leading to system degradation

none Amber light

Information None Green light