Joined: 30 Aug 2013
|Posted: Mon Sep 02, 2013 7:59 am Post subject: RTF Discipline
Communication between pilots and controller is a four way process; information is transmitted, received, read back and received. There are, therefore, several chances of errors being made and consequently the need for clear and unambiguous communication between pilots and controllers is essential. It has been recognized as an important factor in assisting the safe and expeditions operation of aircraft, and by ensuring a high level of RTF (radio telephony) discipline pilots can help minimize risk.
In a recent survey of RTF usage it was found that 80% of RTF transmissions by pilots, in some form or other, were incorrect. Over a third of initial calls on departure were incomplete, and a quarter of read backs of clearances were in error. When pilots provide incomplete information on their initial contact departure calls air traffic controllers are required to ask them for the information. This inevitably leads to additional calls on what might be an already busy frequency, leading to frequency congestion. By ensuring the read back of clearances are correct and the departure call adheres to the published format pilots can, firstly, reduce the risk of level busts with the attendant risk of a collision and, secondly help in reducing frequency congestion.
The following provides advice on the correct RTF usage to be used:
CLEARANCE READ BACK: An accurate read back of a clearance ensures mutual understanding between you and controller about what you are going to do. After receiving the clearance you must read back the following information.
. Call sign . Destination . SID . ATS Route (if received) .Cleared level/altitude . Squawk
CALL ON DEPARTURE: When flying SID you must include the following information on initial contact with the first ATS unit.
. Call sign .SID . Current or passing altitude/level .Initial climb altitude/level (i.e. the first level at which you will level off unless otherwise cleared.)
The inclusion of the current or passing level enables the controller to verify the accuracy of the Mode C read out. Equally important is the inclusion of the initial climb level. This confirms that your understanding of your cleared level is the same the controller`s.
FREQUENCY CHANGES: When changing frequency, unless otherwise instructed, the initial call must be call sign and altitude/level only. If you have been assigned a speed or a heading, this information must also be included in the initial call on the new frequency. If you are climbing or descending, the call must be the cleared level/altitude only. Mode C confirmation is not required in this case because it has already been verified on departure.
In the safe and critical flying environment there can be no room for mis- interpretation, therefore the standard phrases and words used in RTF communication have been carefully chosen to avoid ambiguity, and to ensure their meaning is self explanatory. But some words needed additional clarification.
TAKE-OFF – this term will only be used in the context of a clearance to take-off.
DEPARTURE – the use of the word departure does not imply a clearance to take-off. It is the information concerning action after take-off.
FLIGHT LEVEL WUN HUNDRED etc. - flight levels ending in hundreds should always be transmitted as hundred rather zero zero. Studies have shown that the use of “zero zero” can be confused with the adjacent number i.e. One zero zero confused with one one zero.
DEGREES- any heading should always be followed by the word “degrees”. This is to avoid possible between heading and level or speed.
TO/FOR- the words “to” or “for” should not be used when climbing or descending to flight level/altitude. It is easily confused with “two” or “four”.
ALTITUDE- always add word “altitude” and “feet” when flying on QNH, so controller knows that you are flying below transition altitude on QNH.
Good RTF discipline is a significant factor in minimizing errors in communication. It is therefore important for pilots to use standard RTF communication to reduce the risk of misunderstanding. By applying their professional skills in their use of the radio pilots are able to make a significant contribution to flight safety.