شريحة الإخلاء (Evacuation Slide)

What Is an Evacuation Slide?

An evacuation slide is an inflatable, inclined escape chute attached to each aircraft exit door — including over-wing exits on some aircraft types — that deploys automatically when the door is opened in armed mode, allowing occupants to slide rapidly from the aircraft to the ground or water surface. Evacuation slides are a mandatory safety feature on all commercial transport aircraft certified for more than 44 passengers. They are designed to enable the complete evacuation of an aircraft within 90 seconds using half the available exits — the demonstration standard set by FAA and EASA.

How It Works

The slide is packed into a rigid container at the base of the door. When a flight attendant arms the door and the door is subsequently opened from inside or outside, a girt bar attached to the door frame pulls the slide pack release mechanism. Nitrogen and carbon dioxide gas from an inflation cylinder inflate the slide in 6–12 seconds. The slide extends to the ground at an angle of approximately 32°, providing a rate of descent fast enough to clear a full cabin within the 90-second certification limit. "Slide/raft" combination units are fitted at over-water exits on aircraft certified for ETOPS operations; these can be detached and used as life rafts once passengers reach the water.

Types and Standards

• Single-lane slide: Standard at narrow exits; one passenger at a time.
• Dual-lane slide: Wider slide at main exits on wide-body aircraft; two passengers simultaneously, side by side.
• Slide/raft: Detachable unit, doubling as a life raft for over-water ditching survivability.
• Off-wing slide: Used on some aircraft where the over-wing exit opens onto a wing surface too high for a safe jump.

Interesting Facts

• The A380's evacuation slides are among the tallest in commercial aviation — main deck slides extend over 5 metres to the ground, while upper deck slides reach over 9 metres. The upper deck evacuation rate is a critical certification challenge.
• Accidental slide deployments — door opened without disarming — are disturbingly common, causing injuries and significant cost. Airlines report dozens of inadvertent deployments per year globally.
• The full-aircraft 90-second evacuation demonstration required for certification must use volunteer evacuees of mixed demographics, including elderly and disabled participants — the result must be achieved with half the exits blocked.
• Slide repacking and inspection — required after every deployment, training exercise, or periodic maintenance check — costs airlines thousands of dollars per slide unit.