First of all I would like to mention about Air Traffic Services.

1. Air Traffic Control Service ATC.

1. Aerodrome Control Service
2. Approach Control Service
3. Area Control Service

2. Flight Information Service
3. Alerting Service
4. Flight Advisory Service

These are the main ATS services. Then I would like to explain about main objectives of ATS.

a) Prevent collisions between aircraft;

b) Prevent collisions between aircraft on the maneuvering area and obstructions on that area;

c) Expedite and maintain an orderly flow of air traffic;

d) Provide advice and information useful for the safe and efficient conduct of flights;

e) Notify appropriate organizations regarding aircraft in need of search and rescue aid, and assist such organizations as required. (ICAO 2013)

1. Prevent collisions between aircrafts.

There are two boundaries in the world which is using in the Aviation.

• Western Bound
• Eastern Bound

Aircrafts which are flying in the Eastern bound, pilots should have to use Odd flight altitude levels. When they are flying to Western bound, Pilots should have to obey Evens flight altitudes. This rule makes sure the safe of aircrafts. Not only that, If the pilots need to descend or climb their aircraft. First of all pilots should have to ask it, from ATC. After ATC unite check the radar and flight altitude, aircraft’s speed, if there are no any aircraft in that rout and they will give the permeation. If there are more aircrafts in that particular area they are asking speeds and estimate time for particular point, then after ATC unite decide the time for pilots to climb or descend. EX. after 15 min. UL302 can climb up to xxx fleet level.

If there are more aircrafts in same route or altitude, ATC check the speeds and change their Flight altitudes.

If there is a busy route, ATC unite change aircrafts speeds and direction. After they help to make sure aircrafts destination route.

Pilots should have to obey ATC instructions while they are flying. Not only that they have to make conversion between Pilots and ATC unite. Because ATC unite always alert about aircrafts speed altitude and their routes. Therefore their instructions will be help to prevent coalition between aircrafts while they are flying.

2. Prevent collisions between aircraft on the maneuvering area and obstructions on that area.

Maneuvering is pilots flying into Aspen’s Pitkin County Airport (ASE) should be aware of FAA Notice NOTC4835, which addresses two safety issues at the field. The notice attempts to mitigate ongoing safety incidents at the Colorado airport involving aircraft, vehicles and pedestrians on runways and non-movement area. Outside the skiing season, the movement/non-movement area boundary line was repositioned closer to Taxiway. (AIN 2013)

When the aircraft parked at Apron, pilots should have to ask from Air Traffic Control Unite “flight number and can we push back and start the engines.” If there are no any aircraft has pushed back and start their engines at the apron, ATC unite gave the permission to push back and start the engines. If there are any aircraft bushed back and stare ATC will delay the permission. Because ATC avoid the collision between aircraft inside the Apron,

Before the take off pilots should have to get the permission from ATC unite. They give the flow of orders, ATC check the taxing ways and runway and clear the taxing ways and runway. Later than they give the taxing number for pilots to enter the runway. Behind ATC give the permission to take off and they maintain aircraft’s altitude. ATC unite has to guarantee safe of aircraft, that’s the reason for clear the taxing ways and runway. It stops collision between aircrafts and vehicles.

Pilots should have to follow the orders of instruction before the landing. ATC will clear the runway for landing. They absorb aircrafts and vehicles in the runway. ATC will provide wind directions, and glide path. If there any takeoff or landing on the runway, ATC late their permission and manage both aircrafts routes.

Under the poor visibility situations they delayed aircrafts takeoff and landing. After they manage and help to reach their destinations.

ATC check every nock and comer inside the airport and prevent collision between aircrafts and obstructions on that area.

c.Expedite and maintain an orderly flow of air traffic.

When the busy routes, ATC manage aircraft’s Speed, Altitudes directions. These changes help to prevent from collision between aircrafts and control the traffic among aircrafts.

Before the take off, ATC check and manage aircraft departure times. ATC will manage all aircrafts to takeoff on time.

When if it is a busy periods or busy airports, step by step, ATC will clear the runway, taxing ways and apron. They will manage airport aerospace’s traffic. Because it will be a reason for air collision.

d.Provide advice and information useful for the safe and efficient conduct of flights.

Aircraft’s Altimeter indicates aircraft’s current altitude with using air pressure. Place to place Air pressure and Density can change. Because of this reason pilots have to enter mean see level pressure to the altimeter. Before the landing pilots have to come through correct glide path, therefore pilots have to know correct altitude of aircraft. ATC unit provide ground pressure mean sea level pressure and density of these areas before the landing. Aircrafts use some countries aero spaces, Flight Information Regents FIR of those counties provide pressure density and temperature to maintain aircraft’s altitude.

Under poor visibility situations ATC provide advisory services for aircrafts to prevent collision between aircrafts and Obstructs in the airport area.

Below the connection failure situations between Aircrafts and ATC unite, ATC provide advises using signals. Those signals are useful for the safe landing. Efficiently they check the failures of aircraft and provide some advices within shorter time.

ATC unite always alert about their Flight Information Regent area FIR and provide information for aircrafts. Those advise and Information will help to control traffic of aero space. It will make sure the safe about aircrafts.

Physical appearance of the control tower.

Fig. 01

Control Tower

Building and Terminals

Apron

Ramp Area

Hanger

Taxing way

Runway

This structure shows the basic idea of an airport. Air Traffic Controlling Tower is situated in witch is the place where can get the fully and cleared view point. It is the highest building in that area. ATC members can get the fully 360 degree view of an airport.

Control tower height and location affects airport safety and construction costs, the FAA had no means to measure quantitatively the improvement in air traffic controller visibility that can be gained by changing the tower height and location on the airport surface, and there was no required minimum criterion for tower height.

FAA human factors specialists and Airport Facilities Terminal Integration Laboratory personnel created and conducted tower setting simulations of different existing towers to establish a performance baseline of a controller’s ability to detect and identify aircraft on the airport surface at distance points. Research results were used to determine requirements for future tower construction projects, ensuring safe minimums and constraining costs of the nation’s airport investments. Prior to the simulation, human factors researchers refined and validated an experimental approach and methodology to evaluate the human performance characteristics affecting tower setting decisions. This effort supports the FAA Flight Plan Goals for Increased Safety regarding the FAA Safety Management System (SMS) initiative to update the FAA Order for tower. (FAA 2010)

ATC unit always alerting in the airport and always checking movement and non movement areas of an airport. Its prevent collisions between aircraft on the maneuvering area and obstructions on that area ATC can provide correct advisory service because of the clear view. Then it’s expedited and maintains an orderly flow of air traffic. Easily ATC can provide advice and information useful for the safe and efficient conduct of flights because of 360 clear degrees.

Communication failure procedures.

According to my knowledge an aircraft operated as a controlled flight shall maintain continuous air-ground voice communication watch on the appropriate communication channel of, and establish two-way statement as necessary with, the appropriate air traffic control unit, except as may be prescribed by the appropriate ATS authority in value of aero planes.

If it is a communication failure precludes aircraft shall comply with the communication failure procedures, and with such of the following procedures as are appropriate. The aircraft shall attempt to establish communications with the appropriate air traffic control unit using all other available means. In addition, the aircraft, when forming part of the aerodrome traffic at a controlled aerodrome, shall keep a observe for such instructions as may be issued by visual signals.

If in visual meteorological conditions, aircraft has to:

a. Continue to fly in visual meteorological conditions b. Land at the nearest suitable aerodrome c. Report its arrival by the most expeditious means to the appropriate air traffic control unit. (ICAO 2013)

If in instrument meteorological conditions or when the pilot of an IFR flight considers it inadvisable to complete the flight in peace with the aircraft shall:

In airspace where radar is not used in the provision of air traffic control, maintain the last assigned speed and level, or minimum flight altitude if higher, for a period of 20 minutes next the aircraft’s breakdown to report its position over a compulsory reporting point and thereafter adjust level and speed in accordance with the filed flight plan.

Where radar is used in the provision of air traffic control in airspace, maintain the last assigned speed and level, or least flight altitude if higher, for a period of 7 minutes following.

1) The time the last assigned level or minimum flight altitude is reached

2) The time the transponder is set to Code 7600

3) The aircraft’s failure to report its position over a compulsory reporting point

Whichever is later, and thereafter adjust level and speed in accordance with the filed flight plan

When an aircraft station fails to establish contact with the aeronautical post on the designated frequency, it shall attempt to establish contact on another frequency appropriate to the route. If this attempt fails, the aircraft place shall attempt to establish communication with other aircraft or other aeronautical stations on frequencies appropriate to the route. In addition, an aero plane operating within a network shall supervise the appropriate Very High Frequency for calls from nearby aircraft. If necessary, include the addressee for which the message is intended. Procedures for Air Navigation Services Recommendation — in network operation, a message which is transmitted blind should be transmitted twice on both primary and secondary frequencies. Before changing frequency, the aircraft station should announce about changes. (K.Haroon 2005)

Visual signals and their use in Airport.

In a case of a radio failure, pilots should have to land their aircraft immediately. Therefore air traffic control may use a signal lamp to direct the aircraft. The signal lamp has a focused bright beam and is capable of emitting three different colors red, white and green. These colors may be flashed or steady. Its have different meanings to aircraft in flight or on the ground. Aircraft can acknowledge the instruction by rocking their wings, moving the ailerons if on the ground, or by flashing their landing or navigation lights during in the darkness also.

Lights and Signals from Aerodrome.

Fig.02

(FAA 2014)

Maneuvering Area Marking Signals.

Runway & Taxiway Signs

Visual Approaching Navigational Aids.

Any manmade objects with easy to find the way and approach for pilots. VASIS Lights.

Visual Approach Slope Indication System

White/White Too Height Red/White on Glide Path Runway Runway Red/Red Too Low Runway Fig.17

PAPI Lights

Precision Approach Path Indicator

Fig.18 Runway 4 Whites – Too High

3 Whites / 1 Red – Slightly High

2 Whites / 2 Red – On Glide Path

1 Whites / 3 Red – Too Low

Relationship among Runway, Taxing and Control Tower.

Runway

A defined area on a land aerodrome prepared for landing and taking off of aircraft called as a runway.

Taxing way

A general idea is path on a Land aerodrome established for taxiing of aircraft and to provide a link between apron and runway.

Control Tower

It is the unite where control aircrafts vehicles and maneuvering area. Air Traffic Controlling Tower is situated in witch is the place where can get the fully and cleared view point. It is the highest building in that area. ATC members can get the fully 360 degree view of an airport.

Runway, Taxiing Ways and Apron have linked with Air Traffic Control Tower. Because it is the most responsible place. ATC tower Control Approaching lights Runway lights, Taxing lights, Runway edge lights, Runway centerline, Runway threshold Runway end. There is a flow of orders, before the landing or take off. Then tower is the place where the guided aircrafts. They always check the airport area and make sure the safe of aircrafts, vehicles, and peoples. When the aircraft pushed back and start their engines and until their take off, ATC provide instructions using taxing and runway signals for safety efficient.

If the aircrafts ready to take off, firstly ATC has to clear taxing and runway from other aircrafts and vehicles. Using lights systems and signals they will remove all the vehicles and aircrafts for safety. Because tower has a rich and clear visibility. If it is an emergency ATC tower will make decisions and Inform those thing for other parties. Therefore they can declare it easily Always they will make sure the safe of an Airport.

Role of tower controller.

1. BEFORE Transmitting Listen-out carefully to ensure no interference from another station
2. Be familiar with Good Microphone operating techniques
3. Use a normal conversation tone, & speak Clearly & Distinctly
4. Maintain an even rate of speech ï‚£ 100 words per minute, speak even slower when recipient writes-down
5. Maintain a constant Speaking Volume level
6. A slight pause before & after numbers assists to make it easier to understand
7. g) Avoid using hesitation sounds such as “er”
8. h) A constant distance from ‘mic’ recommended if a modulator with a constant level is not used
9. i) Suspend speech temporarily if turning your head away from ‘mic’
10. j) Depress PTT fully before speaking & do not release it until message is complete to ensure transmission of entire message
11. k) Long messages be interrupted momentarily to permit the transmitting operator to confirm the Frequency in use is Clear, & if necessary to permit the recipient to request repetition of any parts not received. (Exforxys 2012)

Advices for Air Traffic Controllers.

• Hold the microphone about one inch from the mouth.
• Speak directly into the microphone.
• Speak clearly, plan what you intend to say.
• Don’t clip transmission.
• Listen out before the transmit.
• Don’t expect an immediate answer. (wait 10-15 seconds before trying again)
• Establish communications. (using the phraseology)
• Wait for a reply.

References

Journals

ICAO, 2013, About Annex 11, Air Traffic Services first edition , ICAO, Montreal 01

ICAO, 2013, Annex 10, , 5.2.2.7.1.1, Communication failure procedures 04

ICAO, 2013, Annex 10, , 5.2.2.7.1.1, Communication failure procedures 05