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SAFETYffeeeeddback

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FINDINGS FROM INCIDENT REVIEW PANEL (IRP) AND

BOARD OF INQUIRY (BOI)

Extract from the last Safety Feedback 6/ATC/2013

Traffic is increasing and likewise workload. Unfortunately, active listening becomes

even more critical with the increasing traffic and workload;

Every time we coordinate, there is a potential for miscommunication to occur.

There is no substitute for good RTF technique. Speaking very fast during busy periods

may not necessarily get the job done faster. Not using full callsigns can be habit

forming with safety implications;

Since then, two IRPs and one BOI had been convened and the same issues cropped up. In

one incident, an aircraft was cleared to the holding point for an intersection departure. The pilot

did not read back the clearance but instead inquired on the intersection taxiway. The non

readback to the clearance was not challenged. The aircraft lined up via the intersection with

another aircraft already lined up at the beginning of the runway. The system alert activated –

no undesired outcome.

In another incident, the original coordination between the en route and Tower was for the en

route to resolve the traffic conflict before handing over to the Tower. The traffic involved an

ATR72 at FL170 and a B738 overtaking and descending through. However, the ATR decided

to maintain FL150. En route then notified Tower that en route will now clear the B738 to FL160.

This was not challenged by the Tower which now meant that Tower will have to resolve the

traffic conflict. However, when the B738 contacted the Tower, the B738 was given a descent

clearance through the level of the ATR72. TCAS alerted the pilot of the B738. The pilots of the

two aircraft then became air traffic controllers. They coordinated among themselves to resolve

the traffic conflict.

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In the first incident while we can argue that the pilot was given the correct clearance i.e to the

holding point, the clearance was never read back. With the stop bar lights not lighted [a long

standing airport deficiency], the pilots may have thought a line-up was permitted.

In the second incident, it was clear to the en route controller that the second coordination meant

that en route will no longer resolve the traffic conflict. However, it was lost to the Tower controller.

The Tower controller maintained that his earlier coordination that en route resolved the traffic

conflict was never amended.

Were both cases an outcome of non-active listening?

This is not about fault finding. All of us have been guilty of non-active listening.This is just to

better understand how our actions or inactions can easily lead to a misunderstanding

especially when influenced by other threats, e.g. the stopbar lighting deficiency.

The third incident revealed something else – lack of attention to proper RTF technique. So, as

revision – read and practise the following guidelines found in MATS and Doc 9432.

MATS 1

Controllers should avoid:

a) too rapid delivery of instructions especially with pilots who are not fluent in the English

language;

b) the assumption that visiting pilots are as familiar with the local area and airfield as the

locally based pilots;

c) verbosity and excessive use of courtesies;

d) using hesitation syllables such as „er‟ or „ah‟ „mmm‟ etc.; and

e) entering into non-operational conversation with pilots.

Doc 9432 – Manual of Radio telephony

The following transmitting techniques will assist in ensuring that transmitted speech is clear and

satisfactorily received:

a) before transmitting, listen out on the frequency to be used to ensure that there will be no

interference with a transmission from another station;

b) be familiar with good microphone operating techniques;

c) use a normal conversational tone, and speak clearly and distinctly;

d) maintain an even rate of speech not exceeding 100 words per minute. [try this – I think all of

us maintain a speech rate of more than 100 words per minute]. When it is known that

elements of the message will be written down by the recipient, speak at a slightly slower

rate;

7 / ATC / 2013 12 Nov 2013

e) maintain the speaking volume at a constant level;

f) a slight pause before and after numbers will assist in making them easier to understand;

g) avoid using hesitation sounds such as “er”;

h) be familiar with the microphone operating techniques, particularly in relation to the

maintenance of a constant distance from the microphone if a modulator with a constant

level is not used;

i) suspend speech temporarily if it becomes necessary to turn the head away from the

microphone;

j) depress the transmit switch fully before speaking and do not release it until the message is

completed. This will ensure that the entire message is transmitted.

CHEW LAM LEONG

ATS Safety Management Unit

6.5 seconds

a new

record!