VCSS - Conversion Training Mod4_ Additional_11 May 2016

7/25/2019 VCSS - Conversion Training Mod4_ Additional_11 May 2016

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Voice Communication Switching System (VCSS)

Voice Communications Switching System

(VCSS)

ATMS Conversion TrainingModule 4

Hands-on Practice

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From the results of the frequency coupling test, the first

syllable of R/T transmissions will be cut occasionally and

cannot be heard when under heavy R/T workload

situation This phenomenon occurred because appropriate delay

time is required by the system to avoid endless hunting

among coupled frequency channels

This phenomenon is technically inevitable

(PaRT Manual Edition 2.0 Part 8 Chapter 1 paragraph 3.9)

Frequency Coupling

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When two aircraft are transmitting at the same time on

different frequencies, VCSS does NOT provide any

audio and visual alert.

Controllers will NOTbe aware that another aircraft is

transmitting at the same time.

Colleagues are reminded of possible cross

transmissions between two aircraft when frequenciesare coupled.


Frequency Coupling

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Audio Path SettingFoot Switch

According to the system design, when using the foot switchto Press-to-Talk (PTT), all the audio signal collected from

the four plug-in sockets in the Headset Control Unit (HCU)

and the fixed handset are transmitted to the air when foot

switch is pressed.

In order to allocate the R/T transmissions of the working

controller when using the foot switch, the Foot Switch is

now reconfigured to Controller 1 and Controller 2sockets in the HCU only.

(PaRT Manual Edition 2.0 Part 8 Chapter 1 paragraph 5.6.1)

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Working controllers (including students) are required to

plug the headset into the Controller 1 or Controller

2 socket for Foot Switch and headset PTT

Controllers can only use Headset PTT to transmit when

headset is plugged in Instructor 1 and Instructor

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When a third party requires to plug into the working

position (but not the working controller), the headset

shall be plugged into the Instructor 1 or Instructor 2

socket.

During OJT, instructors are required to plug the headset

into the Instructor 1 or Instructor 2 socket to execute

the priority override function.


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Audio Path SettingIntercom

According to the system design, when an intercom call isconnected between two working positions, all the audio collected

from the four plug-in sockets in the HCU and the fixed handset

will be put through to the receiving end

For example, during OJT, instructor and controller will put through

to the receiving party on the intercom at the same time if both are

speaking near the mouthpiece

OJTIs and the third person are to be mindful to avoidinadvertently talking over the mouthpiece of the headset


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Audio Path SettingIntercom

When handing over and taking over watch, please pay

attention to the position of the microphone so as to prevent

any unintentional breakthrough into the intercom

transmissions.

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Use of Split Function

When HCU is in split mode:

- Instructor 1 and Controller 1 are for ground-ground

communications

- Instructor 2 and Controller 2 are for air-air

communications

Split function can be used under busy traffic situation.

Supervisors shall be informed before using this function

(PaRT Manual Edition 2.0 Part 8 paragraph 5.4)

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Long Ringing Tone

When there is an incoming call, the ringing

tone will continue until the call is answered

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Divert Calls to Other Working Position

Incoming calls (i.e. intercom, IASC and

telephone calls) can be diverted from one or

more working positions to another designatedworking position.


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Use of Headset or Fixed Handset

Having consulted SSQOs, the use of headset

and fixed handset can follow current practice

to suit stream operation

Fixed handset can be used a backup to

malfunction of HCU and headset.

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Technique to Unplug Headset

There is an adjustable ring at the front part of

the headset plug

Pull the ring a bit and then pull the plug gently

to unplug the headset from the HCU

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Documents

VCSS - Conversion Training Mod4_ Additional_11 May 2016