1. Avionics Systems Day 6

2. 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

3. The control head of an ATC transponder

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

5. 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

6. 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

7. 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

8. 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

10. 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

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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

19. 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

21. 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

22. 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

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

24. 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

25. Intercom System
 Cabin interphone system
 Amplified audio signals allow
communication between members of the
flight crew or with the passengers
 Public address system

28. Intercom System
 Service Interphone System
 Allows communication between flight crew
& ground personnel or mechanics

31. The End!
(for today)
