The document is an internship report submitted by Muhammad Dildar Ahmed from IQRA University about his internship at Pakistan International Airlines from July 1-15, 2014. The report provides information on the various telecommunication systems used on aircraft, including HF/VHF communication, GPS, weather radar, transponders, and cockpit voice/flight data recorders. It also describes navigation instruments such as automatic direction finders, distance measurement equipment, traffic collision avoidance systems, and landing systems. The internship involved learning about these systems on Boeing 777, 747 and 310 aircraft.

1. INTERNSHIP REPORT 2014
Pakistan International Airlines
From 1st of July 2014 to 15th of July 2014
MUHAMMAD DILDAR AHMED
IQRA UNIVERSITY
TELECOMMUNICATION ENGINEERING
Muhammad Dildar Ahmed
IQRA University

2. INTERNSHIP REPORT 2014
Muhammad Dildar Ahmed
IQRA University
Introduction
The purpose of the internship was to introduce the
telecommunication systems that are used in aircrafts. These
systems include HF and VHF communication Systems, GPWS, ADF
(automatic direction finder), CVR (cockpit voice recorder), Weather
radar, ATC (air traffic controller), LRRA (low arrange radio
Altimeter), DME (distance measurement equipment), TCAS (traffic
collision avoidance system), IFE (interactive flight equipment), VOR
(VHF Omni Range), ILS (Information Landing System), Marker
Beacon System. We have also learned the working of Air Craft’s i.e.
about Rudders, Elevator, Wing, Spoilers. This Internship was
basically study of PIA aircrafts specially Boeing-777, Boeing-747
and Boeing-310.

3. INTERNSHIP REPORT 2014
Muhammad Dildar Ahmed
IQRA University

4. INTERNSHIP REPORT 2014
HF Communication:
It is used for long distant communication. It uses sky wave propagation. The power
requirement of HF transceivers is (100-200) but 120 is recommended. In PIA aircrafts 2
HF transceivers are used. At a time 1 will work because of Single HF Antenna.
VHF Communication:
It is used for communication up to 150 miles. It is mostly used at the time of Take-off
and landing. The power requirement of VHF transceivers is (18-28) but 22 watt is
recommended. In PIA aircrafts 3 VHF transceivers are used. 3 can be Used
Simultaneously
Muhammad Dildar Ahmed
IQRA University

5. INTERNSHIP REPORT 2014
Automatic Direction Finder (ADF)
An automatic direction finder (ADF) is an aircraft radio-navigation instrument which
automatically and continuously displays the relative bearing from the ship or aircraft to
a suitable radio station. ADF receivers are normally tuned to aviation operating in the
LW band between 190 – 535 kHz. Like RDF units, most ADF receivers can also receive
medium wave (AM) broadcast stations, though as mentioned, these are less reliable for
navigational purposes.
The operator tunes the ADF receiver to the correct frequency and verifies the identity
of the beacon by listening to the Morse code signal transmitted. On aviation ADFs, the
unit automatically moves a compass-like pointer (RMI) to show the direction of the
beacon. The pilot may use this pointer to home directly towards the beacon, or may
also use the magnetic compass and calculate the direction from the beacon (the radial)
at which their aircraft is located.
Unlike the RDF, the ADF operates without direct intervention, and continuously
displays the direction of the tuned beacon. Initially, all ADF receivers, both marine and
aircraft versions, contained a rotating loop or ferrite loop stick aerial driven by a motor
which was controlled by the receiver. Like the RDF, a sense antenna verified the correct
direction from its 180-degree opposite.
More modern aviation ADFs contain a small array of fixed aerials and use electronic
sensors to deduce the direction using the strength and phase of the signals from each aerial.
The electronic sensors listen for the trough that occurs when the antenna is at right angles to
the signal, and provide the heading to the station using a direction indicator. In flight, the
ADF's RMI or direction indicator will always point to the broadcast station, regardless of the
aircraft's attitude or heading. Such receivers can be used to determine current position, track
inbound and outbound flight path, and intercept a desired bearing. These procedures are also
used to execute holding patterns and non-precision instrument approaches.
Muhammad Dildar Ahmed
IQRA University

6. INTERNSHIP REPORT 2014
Cockpit Voice Recorder (CVR)
A cockpit voice recorder (CVR), often referred to as a "black box, is a flight recorder
used to record the audio environment in the flight deck of an aircraft for the purpose of
investigation of accidents and incidents. This is typically achieved by recording the
signals of the microphones and earphones of the pilots’ headsets and of an area
microphone in the roof of the cockpit.
Where an aircraft is required to carry a CVR and utilizes digital communications the CVR
is required to record such communications with air traffic control unless this is
recorded elsewhere. As of 2005 it is an FAA requirement that the recording duration is
a minimum of thirty minutes, but the NTSB has long recommended that it should be at
least two hours.
Muhammad Dildar Ahmed
IQRA University

7. INTERNSHIP REPORT 2014
Low Range Radio Altimeter
Low range radio altimeter (LRRA) or simply RA measures altitude above the terrain presently beneath an
aircraft or spacecraft.
This type of altimeter provides the distance between the plane and the ground directly
below it, opposed to a barometric altimeter which provides the distance above a pre-determined datum,
usually sea level Radar altimeters are frequently used by commercial aircraft for approach and landing,
especially in low-visibility conditions (see instrument flight rules) and also automatic landing, allowing the
autopilot to know when to begin the flare manoeuvre.
In civil aviation applications, radio altimeters generally only give readings up to 2,500 feet (760 m) above
ground level (AGL) Radio altimeters are an essential part in ground proximity warning systems (GPWS),
warning the pilot if the aircraft is flying too low or descending too quickly.
However, radar altimeters cannot see terrain directly ahead of the aircraft, only that directly below it
functionality requires either knowledge of position and the terrain at radar which uses technology similar
to a radio altimeter.
Muhammad Dildar Ahmed
IQRA University

8. INTERNSHIP REPORT 2014
Distance Measurement Equipment DME
Distance measuring equipment (DME) is a transponder-based radio navigation technology
that measures distance by timing the propagation delay of VHF or UHF radio signals. Aircraft
use DME to determine their distance from a land-based transponder by sending and receiving
pulse pairs - two pulses of fixed duration and separation. The ground stations are typically co-located
with VORs. A typical DME ground transponder system for en-route or terminal
navigation will have a 1 kW peak pulse output on the assigned UHF channel. A low-power DME
can also be co-located with an ILS GLIDE SLOPE where it provides an accurate distance
function, similar to that otherwise provided by ILS Marker Beacons.
Muhammad Dildar Ahmed
IQRA University

9. INTERNSHIP REPORT 2014
Traffic Collision Avoidance System (TCAS)
A traffic collision avoidance system or traffic alert and collision avoidance system
(both abbreviated as TCAS) is an aircraft collision avoidance system designed to
reduce the incidence of mid-air collisions between aircraft. It monitors the airspace
around an aircraft for other aircraft equipped with a corresponding active
transponder, independent of air traffic control, and warns pilots of the presence of
other transponder-equipped aircraft which may present a threat of mid-air collision
(MAC). It is a type of airborne collision avoidance system mandated by the
International Civil Aviation Organization to be fitted to all aircraft with a maximum
take-off mass (MTOM) of over 5700 kg (12,586 lbs) or authorized to carry more than
19 passengers.
Official definition from PANS-ATM (Nov 2007): ACAS / TCAS is an aircraft system
based on secondary surveillance radar (SSR) transponder signals which operates
independently of ground-based equipment to provide advice to the pilot on
potential conflicting aircraft that are equipped with SSR transponders.
In modern glass cockpit aircraft, the TCAS display may be integrated in the
Navigation Display (ND); in older glass cockpit aircraft and those with mechanical
instrumentation, such an integrated TCAS display may replace the mechanical
Vertical Speed Indicator (which indicates the rate with which the aircraft is
descending or climbing).
Muhammad Dildar Ahmed
IQRA University

10. INTERNSHIP REPORT 2014
In-Flight Entertainment (IFE)
In-flight entertainment (IFE) refers to the entertainment available to aircraft
passengers during a flight. At first, IFE consisted of looking out the window. (Zeppelin
sightseeing flights were available in Europe before the First World War.) In 1936, the
airship Hindenburg offered passengers a piano, lounge, dining room, smoking room,
and bar during the 2-1/2 day flight between Europe and America. ) After the Second
World War, IFE was delivered in the form of food and drink services, along with an
occasional projector movie during lengthy flights. In 1985 the first personal audio
player was offered to passengers, along with noise cancelling headphones in 1989.
During the 1990s the demand for better IFE was a major factor in the design of
aircraft cabins. Before then, the most a passenger could expect was a movie
projected on a screen at the front of a cabin, which could be heard via a headphone
socket at seat.
The largest manufacturers of IFE systems are Panasonic Avionics Corporation, Thales
Group, Rockwell Collins and Live TV. Design issues for IFE include system safety, cost
efficiency, software reliability, hardware maintenance, and user compatibility
VHF Omni Range (VOR)
VOR, short for VHF Omni directional radio range, is a type of radio navigation
system for aircraft. A VOR ground station broadcasts a VHF radio composite signal
including the station's identifier, voice (if equipped), and navigation signal. The
identifier Morse code. The voice signal is usually station name, in-flight recorded
advisories, or live flight service broadcasts. The navigation signal allows the airborne
receiving equipment to determine a magnetic bearing from the station to the aircraft
(direction from the VOR station in relation to the Earth's magnetic North at the time
of installation). VOR stations in areas of magnetic compass unreliability are oriented
with respect to True North. This line of position is called the "radial" from the VOR.
The "intersection" of two radials from different VOR stations on a chart provides an
approximate position of the aircraft.
Muhammad Dildar Ahmed
IQRA University

11. INTERNSHIP REPORT 2014
Information Landing System (ILS)
An Optical Landing System (OLS) is used to give glide path information to pilots in
the terminal phase of landing on an aircraft carrier from the beginning of aircraft
landing on ships in the 1920s to the introduction of OLSs, pilots relied solely on their
visual perception of the landing area and the aid of the Landing Signal Officer (LSO in
the US Navy, or "batsman" in the Commonwealth navies). LSOs used colored flags,
cloth paddles and lighted wands.
Muhammad Dildar Ahmed
IQRA University

12. INTERNSHIP REPORT 2014
What is battery?
An electric battery is a device consisting of one or more electrochemical cells that convert
stored chemical energy into electrical energy. Each cell contains a positive terminal, or
cathode, and a negative terminal, or anode. Electrolytes allow ions to move between the
electrodes and terminals, which allows current to flow out of the battery to perform work.
Lead–acid battery:
Lead acid batteries used in the RV and Marine Industries usually consist of two 6-volt
batteries in series, or a single 12-volt battery. These batteries are constructed of several
single cells connected in series each cell produces approximately 2.1 volts. A six-volt battery
has three single cells, which when fully charged produce an output voltage of 6.3 volts. A
twelve-volt battery has six single cells in series producing a fully charged output voltage of
12.6 volts.
A battery cell consists of two lead plates a positive plate covered with a paste of lead
dioxide and a negative made of sponge lead, with an insulating material (separator) in
between. The plates are enclosed in a plastic battery case and then submersed in an
electrolyte consisting of water and sulfuric acid. Each cell is capable of storing 2.1 volts.
Alkaline battery:
Alkaline batteries are a type of primary batteries dependent upon the reaction between zinc
and manganese dioxide (Zn/MnO2). A rechargeable alkaline battery allows reuse of specially
designed cells. The alkaline battery gets its name becaus e it has an alkaline electrolyte of
potassium hydroxide, instead of the acidic ammonium chloride or zinc chloride electrolyte
of the zinc-carbon batteries. Other battery systems also use alkaline electrolytes, but they
use different active materials for the electrodes.
The capacity of an alkaline battery is strongly dependent on the load. The nominal voltage
of a fresh alkaline cell is 1.5 V. Multiple voltages may be achieved with series of cells . The
effective zero-load voltage of a non discharged alkaline battery varies from 1.50 to 1.65 V,
Muhammad Dildar Ahmed
IQRA University

13. INTERNSHIP REPORT 2014
depending on the purity of the manganese dioxide used and the contents of zinc oxide in
the electrolyte. The average voltage under load depends on level of discharge and the
amount of current being drawn, varying from 1.1 to 1.3 V. The fully discharged cell has a
remaining voltage in the range of 0.8 to 1.0 V.
Alkaline batteries are manufactured in standardized cylindrical forms interchangeable with
zinc-carbon batteries, and in button forms. Several individual cells may be interconnected to
form a true "battery", such as those sold for use with flashlights and the 9 volt transistor-radio
battery.
Navigation:
Navigation is a field of study that focuses on the process of monitoring and controlling the
movement of a craft or vehicle from one place to another. The field of navigation includes
four general categories: land navigation, marine navigation, aeronautic navigation, and
space navigation.
All navigational techniques involve locating the navigator's position compared to known
locations or patterns.
Muhammad Dildar Ahmed
IQRA University

14. INTERNSHIP REPORT 2014
Muhammad Dildar Ahmed
IQRA University