Controller-pilot data link communication

   CPDLC is communication system which allows pilot and controller to communicate with the help of data link. CPDLC allows controllers to issue common clearance directions, such as flight level assignments and constraints, frequencies, route changes and deviations, speed restrictions, and requests for information. The flight crew can then respond.

The CPDLC application provides air-ground data communication for the ATC service. This includes a set of clearance/information/request message elements which correspond to voice phraseology employed by Air Traffic Control procedures. The controller is provided with the capability to issue

· level assignments

· crossing constraints

· lateral deviations

· route changes and clearances

· speed assignments, radio frequency assignments

· various requests for information.

The pilot is provided with the capability to respond to messages, to request clearances and information, to report information, and to declare an emergency. The pilot is, in addition, provided with the capability to request conditional clearances (downstream).A “free text” capability is also provided to exchange information not conforming to defined formats.

The benefits of flight deck integrated ATC systems include the following:

√Enhanced flight crew situational awareness.

√Shift of workload from controller to pilot. For example, controllers can issue sequence positions and pilots can be left to maintain their sequencing without further controller direction.

√Alleviates miscommunication problems.

√Improved efficiency and system capacity by allowing a reduction of necessity to repeat missed messages or correct errors in read-backs.

√Data-link communication can act as a back-up to traditional radio communication.

√Digital communications are (generally) more reliable than analogue communications.

But these radio communications are inherently vulnerable to error.

§ Resources for radio communications (particularly frequencies) are limited.

§ When there is congestion of air traffic it requires from controller high workload

§ Congestion on ATC frequencies results in communication errors, particularly due to blocked transmissions (which themselves only generate further congestion).

Complete the statements.

1. CPDLS is……………………………………………………..

2. It’s principle of work is…….....................................................

3. Its benefits are………………………………………………..

4. Its drawbacks are……………………………………………...

5. I consider that this system can/ can/t be used as………………

 

IX. Comment on the texts. Speak about other examples of air crash due to misunderstanding.

KLM and Pan American collision

This catastrophe occurred at Tenerife airport in 1977. It was a collision of two Bs 747belonging to KLM and Pan Am America airlines that led to about six hundred fatalities. It remains the biggest and the deadliest crash in the history of aviation.

KLM plane was taking off in heavy fog on the airport’s only RW and crashed into the top the Pan Am aircraft taxing to the opposite side.

The investigation concluded that there was a number of contributing factors that caused the crash:

1. KLM captain attempted to take off as soon as possible in order to comply with the company’s duty-time regulations and before the weather deteriorated more. So he decided that Pan Am had already cleared the RW and started take off without distinct clearance from ATC.

2. Dense fog was another major reason of the crash as it limited the visibility so control tower and the crews of both planes were unable to see each other.

3. Simultaneous radio transmissions also resulted in the fact that no message was heard.

4. ATC’s strong Spanish accent and deviation from the standard phraseology by the controller and the KLM pilot were also the contributing factors of the catastrophe.

 

Dan Air crash

On the 25^th of April, 1980 B 727 belonging to Dan Air airline was executing charter flight from Manchester(the UK) to Tenerife (Spain). When the aircraft was on final approach to the airport Tenerife controller gave a holding pattern clearance to it by using the phrase ‘turn to the left’ when he should have said ‘turns to the left’(for circling). The captain complied with controller’s instructions and directed the aircraft left towards the southeast into the area of high mountains. Ambiguous command of Spanish controller disorientated pilot. Moreover ATC cleared the traffic for unrealistic track for holding pattern. In mountainous area for this aircraft it was impossible.

So, the aircraft made a single left turn rather than making circles using left turns. The jet hit a mountain killing 146 people.

 

Crash over JFK

On the 25^th of January in 1990 B707 was carrying out the flight from Bogotá, Spain to JFK, New York. They were flying in holding pattern over JFK for over an hour due to thick fog at the airport. They burnt all the fuel which was already not sufficient for getting to their alternative Boston. Having the fuel for some minutes the pilots addressed the controller with the words “we are running of fuel, we request priority for landing”. For controller it wasn’t an emergency and that’s why priority was not cleared. Soon the engines flamed out due to exhaustion and the plane dived towards the ground.

Misunderstanding between ATC and pilot was caused by the fact that the controller was unaware of linguistic differences of the word “priority” which for Spanish-speaking pilots means emergency. 73 out of 149 people on board perished in the accident.

Collision over Delhi

On the 12^th of November in 1996 Saudi Arabian B747 was en route from New Delhi, India to Dhahran, Saudi Arabia and collided in mid-air with Kazakhstan Il-76 en route from Kazakhstan to New Delhi. All 349 people on both aircraft were killed.

The investigators revealed that it was Kazakhstan pilots’ fault. (due to lack of English) Pilots were relying on their radio operator on communication with ATC. The radio operator asked controller about position of the Saudi airplane. Controller replied “traffic is 8 o’clock now, FL 140”. Pilots with their poor level of English ignored this communication and heard the last phrase “FL 140” understood as clearance for their descent. In some minutes both aircraft impacted.

 

UNIT 5

BIRD STRIKE

I. New vocabulary.

· Impact

· Rubbish dump/ landfill waste disposal site

· To attract birds

· To encounter

· To occur

· To endanger the flight

· To pose hazard/ threat to the aircraft

· To cause significant damage of the plane

· Bird ingestion

· Majority of strikes

· Breeding places

· Resistant to

· To suck the bird

· Flock of birds

· Vulnerable parts of the aircraft

· Prey bird/ predator

· Precaution measures

· Short-time solution

· To eliminate the problem

· Nestling

· Natural habitat

· Roosting site

· Shelter

· Cow scare

· Residential area

· Likelihood

· To jeopardize

· To deteriorate/ to impair

· Sufficient malfunction

· To mitigate the risk

· Constant vigilance of the RW

· To emit high frequency sounds

· To frighten/ chase/ scare the birds away