Inflight Emergencies Flashcards
Define the different types of decompressions
Explosive
An explosive decompression is one that takes place in less than a second. This can be rapidly fatal and may be a result of major structural damage, an explosion or bomb, breaking the fuselage structure causing the air to expel out of the cabin in a rush.
Sudden
A sudden decompression is defined as greater than one and less than ten seconds and is caused by structural damage to the aircraft such as collapse of a door or door seal, windows, fuselage structural damage or failure of pressurisation equipment, leaving fuselage intact but the contained air is reduced to outside air temperature and pressure.
A sudden temperature drop causes fog to form temporarily in the cabin leaving the air very cold, thin and dry. The Flight Crew may commence a steep descent.
Gradual
A gradual decompression is considered a Non-Normal. This is a slow or gradual loss of pressurisation due to a slow pressurisation leak or an air-conditioning failure and the fuselage is intact. Descent will not be as steep as in ‘sudden’ or ‘explosive’ situations. Effect on occupants should be less severe.
This situation is one of the most insidious in pressurised aircraft as Cabin and Flight Crew may not be aware that a gradual loss of pressurisation is taking place. There may be no obvious indications of a gradual decompression. One of the first physiological indications may be ear discomfort or ‘popping’, joint pain, or stomach pain due to gas expansion. Indications may also be mild hypoxic symptoms. Symptoms of hypoxia may become more prevalent as cabin altitude increases but this varies amongst individuals.
What are the physical effects of a decompression?
Some or all of the following may occur:
• Initial effects of Hypoxia
• Sudden boiling of liquids in hot beverage containers and water boilers (risk of scalding)
• Pain in ears and sinuses
• Mist forming in cabin (do not confuse with smoke)
• Air becoming cold and thin
• Need to breathe rapidly
• Disturbance of dust and loose papers
• Discomfort or pain due to pressure of gases trapped in the body (can be relieved by belching and/or passing wind)
What fires do BCF extinguishers not work on?
Metals that react adversely with BCF extinguishant include Titanium and Magnesium, however they need to be at extreme temperatures to react adversely, e.g. a brake fire on the Q200/Q300.
How can crew prevent smoke inhalation.
- Breathe through wet towels/cloths to filter the air and advise passengers to do the same. Hold the cloth over the nose and mouth; and
- Keep as low as possible as the clearest air is closest to the floor and advise passengers to do the same.