VI. Emergency descent

An Emergency Descent may be triggered by several events including:

• Failure of cabin pressurisation system

• Rapid depressurisation may have an effect on the handling of the aircraft

• Damage to a door or window (cracked windshield) which may lead to depressurization

• Fire on board

• Equipment failure

• Unlawful interference

• In the event of an emergency descent, the ACFT may descend without warning or request immediate descent.

Separation to other ACFT may be infringed.

• The pilot may not have time to transmit an emergency squawk and there may be poor or no RTF.

• The higher the ACFT the faster the rate of descent. By doing this, the ACFT will descend through other levels and separation to other ACFT may be infringed.

ATC

In the event of an emergency descent, REMEMBER:

• Follow the ASSIST code of practice

A ‘Acknowledge’ – S ‘Separate’ – S ‘Silence’ – I ‘Inform’ – S ‘Support’ – T ‘Time’

• Other traffic

• Avoiding action

• Traffic information

• Emergency broadcast

• After emergency descent, request intentions

• Is a diversion required?

- inform appropriate aerodromes (civil / military)

• Are there any injuries on board?

• Is the ACFT damaged?

• Consider ACFT still to be in an emergency situation

• Inform pilot about minimum en route altitude

• may require heading change

• Squawk A7700

CREW

VII. Engine failure

Engine failure may be caused by hydraulic or electrical problems, birdstrike, engine on fire, fuel problems, low oil pressure, icing, ingestion of debris, or pilot error.

The effects of an engine failure are influenced by the following factors:

• At what stage of the aircraft’s flight does the failure occur?

Is it during departure or cruise?

• How many engines does the aircraft have?

Is it single engine or multi-engine?

ENGINE FAILURE DURING DEPARTURE

1. Aircraft takes off then departs from aerodrome

2. Engine failure occurs during departure

!!NOTE: Single engine aircraft must now land as soon as possible

3. Continues on straight course then levels off at 1000 to 1.500 ft GND

4. Flaps are retracted and speed increases

5. Aircraft can now climb to safe level to await further decisions

ENGINE FAILURE DURING CRUISE

Aircraft may need to descend in order to:

A. maintain cabin pressure

B. increase speed and airflow to aid engine restart

C. start APU – many APUs need lower altitudes to start

!! NOTE: Single engine aircraft: if engine can’t restart, aircraft must land as soon as possible

ENGINE FAILURE IN ANY AIRCRAFT

Heavy workload in the cockpit restricts the pilot’s ability to communicate with ATC. The crew may take up to 10 minutes to work through the checklist.

In the event of an engine failure, you should expect any of the following:

• Take-off abort

• Deviation from SID

• Intermediate level-off

• Course deviation

• Descent

• Pressurisation problems

• Fuel dumping

• Diversionary or forced landing

• Blocked RWY after landing

Loss of one engine in a multiple engine aircraft reduces power and ability to fly normally:

• propeller driven aircraft may descend to increase speed and adapt cabin pressure

• high altitudes (above FL 200) cannot be maintained

• turns to the side where the engine has failed normally need to be wider

• ACFT will prefer to fly straight and level and in a larger turning radius

Single engine aircraft are often small general aviation aircraft. Flight accident analysis has shown that the main cause of engine failure here is pilot error.

During this critical incident, the pilot should be given every possible support.

Effects of engine failure are:

• loss of electrical power

• loss of navigational systems

• loss of communication systems

• loss of cabin pressure

• loss of avionics systems (e.g. gyro, horizon)

• manual gear extension

ATC