Avionics Systems Day 6

Transponder

Used to help ATC identify aircraft operating in controlled airspace

Transponders operate in the same frequency range as ATC radar

Required to be inspected & tested every 24 calendar months

The control head of an ATC transponder

Transponder

When ATC radar interrogates the aircraft, the transponder automatically responds by sending a four digit identification code

Transponder

The four digit code is registered in the ATC computer along with the aircraft flight plan The controller will see the aircraft

registration number and four digit code on the radar screen

Transponder Functions

Identification (ident) – simply the four digit coded reply

Altitude reporting – transponder is coupled to an encoding altimeter which sends the aircraft altitude with the reply

Collision avoidance – monitors other aircraft transponders in the area & will determine if a collision is possible

Transponder Operation

Transponders operate in three modes Mode A

Identification only Mode C

Identification & Altitude reporting (required in some airspace)

Mode S Identification, Altitude reporting, & collision

avoidance

TCAS

Traffic alerting & Collision Avoidance System Used with mode S transponders Works independently of ground stations If a collision course is detected the system

will display appropriate directions to the pilot to prevent the collision

ELT

Emergency Locator Transmitter Battery powered transmitter required on

all general aviation aircraft Produces a locator signal which can be

used by search & rescue to locate downed aircraft

ELT

Inertia switch activated 6 G forward Also has a manual switch on the ELT, &

usually in the cockpit Frequencies

121.5 & 243 MHz International distress frequencies

ELT

100 Mile range at 10,000 ft 48 Hour capacity Installed in the tail of the aircraft

Provides protection from crash damage when placed as far aft as possible

ELT

Must be tested on a regular basis Every 12 calendar months

The test must be performed within the first 5 minutes of any hour Log book entry should be made after test

ELT Testing

Tune radio to 121.5 With the ELT disconnected from the

antenna turn on the ELT using the switch You should hear the siren

Turn switch to arm position & shake You should hear the siren again

Turn off ELT using the switch Do not let the ELT operate for more than 3

seconds at a time

ELT Battery Check

Battery must be replaced at the time of the expiration date found on the battery case

Or if more than one hour has been depleted from the battery Check maintenance records in the aircraft

logbooks

EPIRB

Emergency & Position Indicating Radio Beacon

New replacement for the ELT Will be required by Feb. 2009 5 Watts of power not ½ watt Digital signal

Identifies owner and aircraft Fewer false alarms Must be registered with the FAA

EPIRB

Picked up by satellites Can be interfaced with aircraft GPS

Pinpoint accuracy .031 kilometers Old ELT 1260 sq kilometers

More rapid response time for rescuers

FDR

Flight Data Recorder Device which monitors & records specific

flight operation parameters for analysis after an accident The “BLACK BOX”

Which is actually bright orange

FDR

Required on all commercial airliners since 1958

Records the last 25 hours of flight Located in the aircraft tail Fire & “G” resistant Transmits a locator signal so it can be

found in the wreckage

FDR

Parameters Altitude & Airspeed Attitude & Direction Vertical acceleration Landing gear position Flight control position Engine power Greenwich mean time “ZULU time”

CVR

Cockpit Voice Recorder Records the last 30 minutes of the flight

deck voice communications Microphone in the cockpit Recorder in the tail Crush & fire resistant Transmits a locator signal so it can be

found

Intercom System

Cabin interphone system Amplified audio signals allow

communication between members of the flight crew or with the passengers

Public address system

Intercom System

Service Interphone System Allows communication between flight crew

& ground personnel or mechanics

The End! (for today)