Air Traffic Control Guidebook PDF - Assessment Centre 2025

Air Traffic Control Guidebook Assessment Centre for Air Traffic Controller Candidates 2025 Contents General introduction....................................................................................................................2...

Air Traffic Control Guidebook Assessment Centre for Air Traffic Controller Candidates 2025 Contents General introduction....................................................................................................................2 Zagreb Area Control Centre (Zagreb ACC).................................................................................2 The importance of communication..............................................................................................4 Radio Communications...........................................................................................................4 Aircraft Identification................................................................................................................8 References..............................................................................................................................9 Copyright © 2019 by Croatia Control Limited All rights reserved. This guidebook is intended only for candidates who partcipate in the assessment centre for selection of air traffic controllers and is considered to be CONFIDENTIAL. Candidates who receive this guidebook as a preparation material for assessment centre are not allowed to distribute this material. Any other use of this material is subject to elimination from the selection process. Air Traffic Control Guidebook is protected by copyright, and permission must be obtained from the author prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. 1 Hrvatska kontrola zračne plovidbe d.o.o. | Assessment Centre 2025 General introduction Air Traffic Control Services (ATC) are provided to ensure safe, orderly and efficient air traffic. They are provided for the purpose of expediting and maintaining an orderly flow of air traffic and preventing: collisions between aircraft in the air and aircraft on the aerodrome maneuvering area collisions between aircraft and vehicles, as well as collisions between aircraft and obstructions on the aerodrome maneuvering area Air Traffic Control Services include: Aerodrome Control Service provided by an aerodrome control tower - TWR, Approach Control Service provided by an approach control unit - APP Area Control Service provided by an area control centre – ACC Zagreb Area Control Centre (Zagreb ACC) In this section you will get a closer look at different jobs and responsibilities in Zagreb ACC. Air traffic control officers (ATCO) manage aircraft though all phases of flight, with a stress on safety, orderliness and efficiency. They use various means of communication, navigation and surveillance in order to give information, instructions and clearances to pilots. You can find more information about typical ATCO activities on our website. Air traffic control services provide controlled flights in a controlled airspace (Control Area - CTA). The controlled area is divided horizontally and vertically into a larger number of sectors. All planes subject to separation must be separated at least 5 NM (9.26 km) and 1000 FT (300 m) vertically. Normally there are two ATCOs working on one position in a shift: one handling incoming flights, and one working the radar. The ATCOs rotate on a position every two hours or one hour, depending on the intensity and complexity of the air traffic, in order to avoid fatigue and lack of concentration which reduce accuracy and promptness of their reactions. All air traffic controllers function as a team. Within an hour, ATCO can control about 40 aircraft in their sector. In peak load periods, ACC can control up to 170 GAT IFR operations per hour with the maximum number of simultaneously open sectors (12 sectors). 2 Hrvatska kontrola zračne plovidbe d.o.o. | Assessment Centre 2025 Flow management position (FMP) is responsible for the day to day monitoring, planning and co- ordination of all Air Traffic Flow Management (ATFM) measures affecting air traffic which is entering, leaving, overflying or remaining within Croatia. ATFM is the service established to provide a safe, orderly and efficient flow of air traffic with maximum ATC capacities used, and to ensure compatibility between the quantity of air traffic, i.e. traffic demand (TD) and the declared capacity of relevant ATC units. The declared capacity is usually referred to as the number of aircraft entering the defined airspace in a specified time period, taking into account all factors that may affect the workload of air traffic controllers responsible for that airspace. The air traffic flow management in the European region is provided by the Eurocontrol's Network Manager Operations Centre (NMOC). Our flow management controllers closely cooperate with the NMOC at the tactical level to ensure aircraft operators, when required, with a relevant alternative, such as adjustment of departure time, change of routes and flight profile, aiming to minimise traffic delays. Flight Data Officer (FDO) is responsible for collecting, maintaining and providing data on all flight operations and the air navigation infrastructure. Some of the tasks include ensuring the admission of flight plans and related messages, checking the accuracy of the received flight plans, entering military flight data into the system etc. Flight Information Centre (Zagreb FIC) is a special sector within the Zagreb Area Control Centre. Their tasks include: activating flight plans, forwarding the data to sectors, providing meteorological reports to pilots, providing navigation assistance for VFR flights if requested. Pilot with the intention to perform a flight in controlled airspace up to 1000 FT (e.g. non-commercial flights) shall contact FIC Zagreb. ACC supervisor (SUP) is an air traffic controller who acts as the focal point for any enquiries regarding the performance of the watch. His job is to ensure the efficient day-to-day management of the ACC. General duties and responsibilities include: managing the staff effectively during the period of watch in order to ensure best use of resources, closely cooperating with FMP in order to co-ordinate ATFM measures, opening and closing sectors. Supervisor’s deputy works closely with Airspace Management Cell (AMC) and manages emergency or abnormal situations such as loss of communication, emergency landings, illegal activities etc. 3 Hrvatska kontrola zračne plovidbe d.o.o. | Assessment Centre 2025 The importance of communication The primary purpose of the ATC system is to prevent a collision between aircraft operating in the system and to provide a safe, orderly and expeditious flow of traffic. The safe operation of the nation’s air traffic control system ultimately depends on reliable and accurate communication between pilots and air traffic controllers. Virtually every instruction, procedure, or clearance used to separate or assist aircraft relies on written or verbal communication. Any miscommunication between participants in the air traffic control system might contribute to or even be the direct cause of an aircraft accident with a subsequent loss of life. For this reason, proper and correct communications procedures must be observed by both pilots and controllers. Many of the accidents and incidents that have occurred over the last fifty years can be attributed to improper or misunderstood communications. Although many improvements to the air traffic control communications system have made it less reliant on verbal or written communication, pilots and controllers will continue to rely on human communication well into the twenty-first century. Thus, controllers must possess a proper understanding of communications procedures and phraseology. Radio Communications Most air traffic controllers use radio equipment to perform their ATC duties. This equipment may be either fairly simple or very complex, depending on the capabilities of the facility. In general, each controller is assigned one or more radio frequencies for communications with pilots and has access to telephone equipment that permits communication with other controllers in the same facility or in adjacent facilities. Controllers are outfitted with standard microphones and speakers or telephone handsets. Each controller has a switching panel to choose whether to communicate with other controllers or to the pilot over the radio. The system is designed so that when the controller is communicating on one particular channel, any message sent to him or her on either the radio or another landline is routed through an overhead speaker. When communicating with pilots or other controllers, a controller should always use the following message format: 1. Identification of the aircraft or controller being contacted. This serves to alert the intended receiver of the upcoming transmission. 2. Identification of the calling controller. This serves to identify who is initiating the communication. 3. The contents of the message. 4 Hrvatska kontrola zračne plovidbe d.o.o. | Assessment Centre 2025  4. Termination. In communications with another ATC facility, the message should be terminated with the controller’s assigned operating initials. This procedure simplifies identification of the controller if a subsequent investigation is necessary. Certain letters and numbers may sound similar to each other when spoken over low-fidelity radio or telephone equipment. In addition, accents and dialects may make it difficult to discern and identify the exact content of a message. To alleviate this problem, a standard for pronunciation of letters and numbers has been approved by. This standard is presented in Table 1. The standardized pronunciations should be used by controllers whenever communicating with pilots or other controllers. Air traffic controllers should also use standardized phraseology when passing along control instructions or various information to pilots or to other controllers. International Civil Aviation Organization (ICAO) has designated English as the international language for ATC communications worldwide. Table 1. Word Pronunciation Word Pronunciation Number Pronunciation A - ALFA AL fah N - NOVEMBER no VEM ber 0 ZE-RO B - BRAVO BRAH voh O - OSCAR OSS car 1 WUN C - CHARLIE CHAR lee P - PAPA pah PAH 2 TOO D - DELTA DELL tah Q - QUEBEC keh BECK 3 TREE E - ECHO ECK oh R - ROMEO ROW me oh 4 FOW er F - FOXTROT FOKS trot S - SIERRA see AIR rah 5 FIFE G - GOLF golf T - TANGO TANG go 6 SIX H - HOTEL hoh TEL U - UNIFORM YOU nee form 7 SEV en I - INDIA IN dee ah V - VICTOR VIK tah 8 AIT J - JULIET JEW lee ETT W - WHISKEY WISS key 9 NIN er K - KILO KEY loh X - X-RAY ECKS ray Decimal DAY SEE MAL L - LIMA LEE mah Y - YANKEE YANG key Hundred HUN dred M - MIKE mike Z - ZULU ZOO loo Thousand TOU SAND 5 Hrvatska kontrola zračne plovidbe d.o.o. | Assessment Centre 2025 The following words and phrases shall be used in radiotelephony communications as appropriate and shall have the meaning ascribed hereunder: Phrase Meaning ACKNOWLEDGE “Let me know that you have received and understood this message.” AFFIRM “Yes.” APPROVED “Permission for proposed action granted.” CANCEL “Annul the previously transmitted clearance.” CHECK “Examine a system or procedure.” (Not to be used in any other context. No answer is normally expected.) CLEARED “Authorized to proceed under the conditions specified.” CONFIRM “I request verification of: (clearance, instruction, action, information).” CONTACT “Establish communications with...” CORRECT “True” or “Accurate”. CORRECTION “An error has been made in this transmission (or message indicated). The correct version is...” DISREGARD “Ignore.” GO AHEAD “Proceed with your message.” I SAY AGAIN “I repeat for clarity or emphasis.” MAINTAIN “Continue in accordance with the condition(s) specified” or in its literal sense, e.g. “Maintain VFR”. NEGATIVE “No” or “Permission not granted” or “That is not correct” or “Not capable”.. READ BACK “Repeat all, or the specified part, of this message back to me exactly as received.” RECLEARED “A change has been made to your last clearance and this new clearance supersedes your previous clearance or part thereof.” REQUEST “I should like to know...” or “I wish to obtain...” ROGER “I have received all of your last transmission.” Note.— Under no circumstances to be used in reply to a question requiring “READ BACK” or a direct answer in the affirmative (AFFIRM) or negative (NEGATIVE). SAY AGAIN “Repeat all, or the following part, of your last transmission.” STANDBY “Wait and I will call you.” Note.— The caller would normally re-establish contact if the delay is lengthy. STANDBY is not an approval or denial. UNABLE “I cannot comply with your request, instruction, or clearance.” WILCO (Abbreviation for “will comply”.) “I understand your message and will comply with it.” WORDS TWICE a) As a request: “Communication is difficult. Please send every word, or group of words, twice.” b) As information: “Since communication is difficult, every word, or group of words, in this message will be sent twice.” 6 Hrvatska kontrola zračne plovidbe d.o.o. | Assessment Centre 2025 Numbers Each number should be enunciated individually unless group form pronunciation is stipulated. For example: Number Group Form Pronunciation Individual Number Pronunciation 1 One One 10 Ten One zero 569 Five sixty-nine Five six niner Unless otherwise specified, when serial numbers are pronounced, each digit should be enunciated individually. Altitudes Unless otherwise specified, every altitude used in the ATC system is measured above mean sea level (MSL). The only routine exception is cloud ceilings, which are measured above ground level (AGL). A controller who must issue an AGL altitude to a pilot should advise the pilot that the altitude is above ground level. Altitudes should be separated into thousands and hundreds, and the thousands should be pronounced separate from the hundreds. Each digit of the thousands number should be enunciated individually, whereas the hundreds should be pronounced in group form: Altitude Pronunciation 3,900 Three thousand niner hundred 12,500 One two thousand five hundred 17,000 One seven thousand Flight Levels Flight levels should be preceded by the words “flight level,” and each number should be enunciated individually: Flight Level Pronunciation 180 Flight level one eight zero 390 Flight level three niner zero Time Every ATC facility around the world must use the same time standard, known as coordinated universal time (UTC). UTC is the same as local time in Greenwich, England, which is located on the 0° line of longitude, also known as the prime meridian. UTC was previously known as Greenwich mean time (GMT). 7 Hrvatska kontrola zračne plovidbe d.o.o. | Assessment Centre 2025 The use of UTC around the world eliminates the question of which time zone a facility or aircraft is located in. In addition, UTC eliminates the need for A.M. and P.M. by using a 24-hour clock system. UTC is always issued as a four-digit number, and the word “o’clock” is never pronounced. The conversion from a 12-hour clock to a 24-hour clock is fairly simple: Any time that has fewer than four digits should be prefixed with a zero. Any time between midnight and noon (A.M.) is not converted to a 24-hour clock. Any time between noon and midnight (P.M.) always has twelve hours added to it to differentiate it from a.m. time. For example, 6:20 a.m. becomes 0620, and 6:20 p.m. becomes 1820. To prevent any confusion when issuing time to the pilot, the controller should suffix any UTC time with the word “zulu” and any local time with the word “local.” Any issuance of time should also be preceded by the word “time.” When issuing time, the controller should enunciate each digit individually: Time (12-hour clock) Time (24-hour clock) Pronunciation 6:20 A.M. 0620 Time zero six two zero zulu 1:35 P.M. 1335 Time one three three five zulu Aircraft Identification Aircraft are identified using standard procedures that help eliminate confusion and misdirected instructions. It is vitally important that control information directed to one aircraft be received by the pilots of that aircraft. It is also exceedingly important that the controller be certain with which aircraft he or she is communicating. If the pilot of one aircraft were to follow the instructions issued to another or if the controller were unsure which aircraft had just made a position report, the air traffic control system would be unable to function properly. An aircraft call sign is a group of alphanumeric characters used to identify an aircraft in air-ground communications. Three different types of aircraft call sign may be encountered (see table below), as follows: Type (a) The characters corresponding to the registration marking of the aircraft (e.g. ABCDE). The name of the aircraft manufacturer or model may be used as a prefix (e.g. Airbus ABCDE); Type (b) The telephony designator of the aircraft operating agency, followed by the last four characters of the registration marking of the aircraft (e.g. Croatia BCDE); Type (c) The telephony designator of the aircraft operating agency, followed by the flight identification (e.g. CTN 1234). 8 Hrvatska kontrola zračne plovidbe d.o.o. | Assessment Centre 2025 The full call sign must be used when establishing communications. After satisfactory communication has been established, abbreviated call signs may be used provided that no confusion is likely to arise. Most authorized airline names are easily recognizable, although a few are somewhat unusual. These approved airline names have been selected to ensure that no two sound similar. Every airline has also been issued a three letter designator to be used in written communications concerning the aircraft. Here are some examples: Airline Name Abbrevation/Identifier Callsign Airfrance AFR AIRFRANCE Aer Lingus EIN SHAMROCK British Airways BAW SPEEDBIRD Emirates Airlines UAE EMIRATES Croatia Airlines CTN CROATIA KLM KLM KLM Lufthansa DLH LUFTHANSA Qatar Airways QTR QUATARI US Airways USA CACTUS Transponder The transponder is the airborne portion of the secondary surveillance radar system. Aircraft have transponders to assist in identifying them on air traffic control radar; and collision avoidance systems have been developed to use transponder transmissions as a means of detecting aircraft at risk of colliding with each other. Air traffic control units use the term "squawk" when they are assigning an aircraft a transponder code. A transponder code consists of four numbers from 0 to 7 (4,096 possible codes). Special codes are used in emergency, as follows: hi-jack (7500), loss of communication (7600), general emergency (7700). References Nolan, Michael, S. Fundamentals of Air Traffic Control, 5th edition. Delmar Cengage Learning, 2011. www.crocontrol.hr www.icao.int 9 Hrvatska kontrola zračne plovidbe d.o.o. | Assessment Centre 2025