7. Read the text and answer the following questions:
✈ What can cause an engine failure?
✈ Why does an engine stall occur?
✈ What can an engine vibration lead to?
✈ What is an engine stall?
✈ What can an engine stall result in?
✈ What are pilots actions in case of engine stall?
It goes without saying that if a single engined aircraft loses an engine the situation is immediately life threatening and there will be a loss of height and the status of the event is an emergency. In three or four engined aircraft the loss of one, is rarely a full emergency or a life threatening situation. Although it's a rare phenomenon, it still occurs. Jet engines are usually very reliable and have a very good safety record. However, failures do sometimes occur. What causes an engine failure to happen? There are several reasons; the most common reasons are the following: engine vibration, metal fatigue, stall, fuel contamination, bird strike and structural failures.
It is a sign that there is clearly something wrong and the engine will soon be shut down. Excess vibration can shorten the life of expensive engine components, e.g. vacuum pumps. Excess and unwanted aircraft vibration can also cause discomfort and fatigue for the flight crew and passengers. The service life of expensive avionics and instruments is shortened considerably when the equipment is operated in a high vibration environment.
Engine stall is commonly applied to the phenomenon whereby an engine abruptly stops operating and turning. It might be due to not getting enough air, fuel, or electrical spark, mechanical failure, or a sudden increase in engine load. As a result, something might go wrong with the fuel burning process that can lead to flame out, and even to the engine destruction. Basically, it occurs at line up. Accidentally, it might happen en route due to pilot's error. In case of engine stall the crew has to shut down the engine or it cuts off. A pilot makes a decision to divert to the alternate. All necessary actions must be taken by an air traffic controller to assist a pilot.
Listening and Speaking Bank.
Unit 8A. Exercise 8-9
Read the instructions and do the task
VIDEO # 32
¸ Watch a video and guess what we are going to discuss now.
1. Match the words in column A to the words with the similar meaning in column B.
2. Match the words in column A to their definitions in column B in the table given below.
a) dangerous, important, serious
e) to widen
7. to extend
11. to collapse
k) to fall down
a) to be likely affected to something
b)able to be stretched
3. to tend
c) a crack or broken part in hard substances
4. to be subject to
d) to have a tendency
e)faster than the speed of the sound
6. supersonic speed
f) to make a small hole through which gases, smoke or liquid can escape from the enclosed space or a container
g)special word, often scientific
8. to vent
h) remains, fragments
9. to detect
i) to notice or discover something that is not easy to see or hear
j) very high
3. Read the text and choose a suitable heading for the paragraph from the list.
Q Metal Fatigue
Q Metal Fatigue Events
Some structural failures are closely connected with metal fatigue. Metal fatigue is a term that we often hear, but seldom fully understand. What is it and when does it occur? Metal fatigue is a fracture mechanism. When things are broken due to metal fatigue, the fracture surface will have certain visible characteristics. Fatigue occurs when a metal or non-metal (plastic or composite) component is subject to swinging or cyclic stress and strain. Material fatigue can also result from pressurization and depressurization of an aircraft during takeoff and landing, or high winds causing the wings to move up and down.
Technological advances and failure analysis have led to numerous ways to minimize the probability of starting fatigue cracks. Various inspection techniques are used looking for any fatigue cracks which might be growing. The idea here is to find and repair or replace the cracked component before the crack reaches a critical size. As with all serious emergencies the first option any crew will want is to get the aircraft safely onto the ground as soon as possible. This problem might also demand slow turns and descents. So the controller must provide immediate diversion to the nearest airfield available.
Listening and Speaking Bank.
Unit 8B. Exercise 4-5.
Read the instructions and do the task.
✈ Watch a video and guess what we are going to discuss now.