Emergency slides are critical elements of aircraft safety, but they can become a hazard in themselves if they are inadvertently deployed. Airbus has developed a simple yet effective means of preventing accidental release of the slides with its Inadvertent Slide Deployment Prevention Light (ISDPL).
Inflation in six seconds
Aircraft emergency slides are crucial bits of kit for use in critical situations. Sitting quietly in a big square box at the bottom of the door, these devices are armed before take-off and kept that way until the plane has safely landed. Should the worst happen, and a quick exit from the plane be required, opening the door triggers the slide activation.
The mechanism is relatively simple. The opening door pulls the slide out of its housing, and the weight of the slide causes it to drop to the ground. As it drops, a lanyard is pulled by the slide, which triggers the inflation mechanism.
An initial boost is provided by a canister of compressed CO2 and nitrogen. This inflates the slide to around one-third of its complete requirement. The rest of the inflation is done by sucking in the ambient air through louvers. This is achieved thanks to the canister gas passing through aspirators at high speed, creating a vacuum. All in all, slides are designed to fully inflate in six seconds or less.
Inadvertent slide deployments
That’s all well and good when you want to use the slide, but what if you don’t? Flight attendants are taught to cross-check each other after landing to ensure the doors have been disarmed. Nevertheless, on rare occasions, something happens that means things don’t quite go to plan, and slides can be accidentally deployed.
In November 2019, a JetSMART A320 almost knocked down ground workers with the stair cart when the slide was accidentally deployed. In June the same year, a passenger on a Pakistan International Airlines flight accidentally opened the aircraft door instead of the lavatory door, causing the slide to deploy and delaying the flight by eight hours.
A Lufthansa A380 crew accidentally deployed the emergency slide at Manchester Airport in 2016, causing a delay of four hours. And in 2014, an Alaska Airlines 737 ended up in a sticky situation when its slide deployed while the stair cart was attached.
— AIRLIVE (@airlivenet) June 22, 2014
These are just a few examples of times when slide activation has gone wrong. In most cases, it results in a costly delay for the flight, but it can also cause a hazard to the ground crews working around the plane. Airbus estimates that the number of Inadvertent Slide Deployments (ISDs) tallies up at 30 – 40 every year!
A solution that will stop these incidents
Airbus has developed a device that could prevent these accidental deployments from being a problem in the future. While aircraft doors already feature clear visual indicators that the door is armed or disarmed, it seems these are all too easy to overlook from time to time.
In order to prevent ISDs, Airbus is offering an additional device that uses both light and sound to indicate whether the door is safe to open or not. Known as the Inadvertent Slide Deployment Prevention Light (ISDPL), it’s a maintenance-free plug-and-play solution that can be installed under the passenger door window.
The device detects an approaching person and signals a warning. Two different warning levels are used depending on the proximity of the person to the door. If the person is within 50 cm of the warning device, it will flash a ‘slide armed’ warning light.
If they get closer, to within 30 cm, the light will be accompanied by an audible warning sound. You can see how it works in the video below.
It’s a simple yet effective safety solution that could prevent slide deployments in error, saving valuable time and hassle for airlines, as well as reducing risks to people on the ground. The ISDPL is already available for the A320 family of aircraft, both as a line-fit and retrofit product.
Have you ever come across this device on a flight? Let us know in the comments.