In case of pressurization problems, the pilots

1) will put on an oxygen mask and check if the oxygen masks were activated in passenger cabin automatically. In this case the headset is switched automatically to a cabin loudspeaker, with the pilot using the microphone in the mask which may reduce the readability to ATC.

2) Then they start emergency descent to the safe altitude ( 3000-4000meters) where people can breathe easily without masks. ( set all thrust levers to idle, extend full speed brakes, descend at maximum permitted speed to MEA( FL 100) or minimum obstacle clearance altitude. In case of structural damage is suspected, reduce the speed as appropriate.)

3) Simultaneously pilots inform ATC about the situation. If ATC can’t be contacted they need to set squawk 7700 or transmit a distress message on emergency frequency.

4) After reaching the safe altitude the crew will evaluate the situation and make up decision to proceed to the nearest alternative or direct to the airport of destination at low altitude. This decision depends on the circumstances of the depressurization, the condition of the aircraft, and the condition of the passengers.

Oxygen is supplied to the passenger for about 10-12 minutes which is enough to perform descent to safe altitude. But if the aircraft flies over the mountainous area where the range of mounts doesn’t allow pilots to get minimum safe altitude, descent will be extended and thus more oxygen will be necessary for sustaining life of the passenger on the board of the aircraft.

ATC has to react quickly:

• Acknowledge emergency on RTF( to receive pilot’s report as for emergency)

• Take all necessary action to vacate the airspace below affected aircraft and provide safe separation with other aircraft

• Impose radio silence if necessary

• Inform supervisor and other concerned services

• May be required to suggest a heading

• May be required to state the minimum safe altitude

• Emergency broadcast if necessary

• After emergency descent, request intentions: diversion, injuries, ACFT damage

Controller has to be aware of the fact that decompression will reduce quality of RTF communication due to oxygen mask. Some of the possible actions are:

• increase the volume of the receiver;

• try to keep aircraft within radar cover;

• have in mind the features of the existing radar system and refrain from attempting to transfer the aircraft to another sector.

Engine failure

Engine failure may be caused by:

• Technical reasons( √fuel system problems such as fuel contamination, fuel leak, fuel exhaustion, fuel control system malfunction, wrong fuel calculation:

√ hydraulic system failure;

√ electrical system malfunction;

√high or low oil pressure

√metal fatigue-demolishing of pylon which attach engine to the wing)

• Weather conditions( icing , hail storm that can impair the work of engine or lead to its stall; volcanic ash- volcanic pieces of rock get into engine, melt, stick to the compressor and thus cause flame out or failure )

• Human factor ( pilot error- f.e shutting down running engine by mistake due to stress or high work loading; poor maintenance service on the ground)

• Outside factor ( bird strike on the engine – depending on the size of the bird it can cause blades damage ; overheating due to ingestion of foreign object or debris on the RW)

There are various engine problems:

√engine cut off

√engine fire

√high vibration

There are two types of engine failure

• “contained” engine failure ( when components might separate inside the engine but either remain within the engine or exit the engine through the tail pipe).

• “uncontained” engine failure can pose a greater risk as ejected debris from the engine exit it at high speeds in other directions, posing potential danger to pressurized aircraft structure.

Consequences.

The consequences of an engine failure depend on the number of engines the aircraft has.

Multi engine aircraft. The loss of one engine on a multi-engine aircraft will reduce its power and the ability to fly normally:

• High altitudes, above FL 200, may not be maintained

• Turns to the side where the engine has failed need to be wider not to get into stall and are expected to be slower

• Propeller driven aircraft may descend to increase speed and maintain cabin pressure

• Heavy workload in the cockpit will restrict the pilot’s ability to communicate with ATC.

• Long and high speed approach and landing ( due to performance limitations attributed to the engine failure the approach speed might be higher than prescribed, which could consequently result in non-established approach, runway excursion and blocked runway)

Single engine aircraft. The engine failure of a single engine aircraft will be followed by

• loss of electrical power

• loss of navigational systems

• loss of communication systems

• loss of cabin pressure

• manual gear extension

Flight accident analysis of single engine failures has shown that a pilot error was the main cause.

In case of engine failure during rolling, take off should be aborted if it occurred before V1 speed, and after complete stop the situation should be reported to ATC.

If it happened after V1 speed the crew must

∙ - perform take-off,

∙ - climb engine out acceleration altitude (from 400 till 1000feet),

∙ - level off the aircraft,

∙ - retract slats and flaps,

∙ - set idle mode for affected engine,

∙ - set full power thrust for running engine,

∙ - make turn and perform landing.

Deviation from SID may be expected - if the engine failure occurs at take-off or after rotation, the crew might not follow the published SID and any associated noise abatement procedures.

It is possible to expect:

• Aircraft may not follow initial departure clearance - it may continue straight ahead or follow its own emergency turn procedure.

• A stepped climb may be required to retract high lift devices.

• A larger radius of turn can be expected due to reduced aircraft performance and maneuverability.

• The flight crew may experience other handling difficulties. For example, turns in one direction may be preferred.

• The flight crew may elect to dump fuel.

• A longer landing distance may be required

In case of engine failure on multi-engine aircraft on cruising level the crew has to increase power on running engine, shut down affected engine, analyze the situation, attempt to restart the engine (if they are sure there is no fire) and decide whether to fly to the nearest alternative or to proceed to the destination ( if fuel amount permits as they will fly at lower altitude and it will result in more fuel consumption).

The aircraft will maintain the lower levels in order to restart affected engine or APU. If the crew decided to restart the engine, necessary increase of speed is provided by descending. Sometimes total engine failure may result in depressurization as air conditioning system is supplied by engines. In this case emergency descent without notifying ATC may be expected.

In case of engine failure on single-engine or multiple engine failure on multi-engine aircraft pilots need to start gliding. The crew will seek the best glide ratio in order to attempt restart of the engine(s) and/or to reach next suitable aerodrome/airfield or place suitable for emergency landing. In this case approach speed may be higher than prescribed, landing distance may be increased. So, this situation can cause

• RW excursion

• Rough landing

ATC has to

• Evaluate the situation( receive pilot’s report as for emergency: reason and consequences)

• Vacate the air space below the affected aircraft

• Impose radio silence, if necessary

• Provide safe separation with the other aircraft in this sector

• Inform supervisor and military services

• Inform landing aerodrome

• Inform the nearest to destination airport ( in case the route is changed)

• Request the information concerning changes on the board

• Clear RWY when ACFT 50 track kilometres from touchdown

• Keep safety strip clear

• Offer pilot extended final

• Avoid go-around

• Ensure that towing equipment on stand-by as appropriate

• In case of forced landing, record last known position and time

If needed inform the crew about next suitable aerodrome and provide alternate aerodrome details (RWY in use, length, surface, elevation, ILS- and NAV-frequencies) and weather information as soon as possible

Inform landing aerodrome of the inbound traffic with engine failure

ATC has to keep in mind that due to engine failure on multi-engine aircraft work loading on the crew increases as they have to perform emergency procedures. So, controller may be informed with some delay and radio communication will be resumed after report of the crew.

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