What is EVAS in Aviation? (Emergency Vision Assurance System)

The Emergency Vision Assurance System (EVAS) is a smoke-protection device that helps pilots maintain their visibility in an inflight emergency. EVAS is a transparent enclosure that fits over the pilots’ heads, providing them with a clean and breathable atmosphere free from smoke, dust, or fumes. The device filters the air, removes the contaminants, and maintains the air pressure and temperature to enhance the pilots’ safety and visibility to fly the aircraft to safety.

EVAS provides complete protection from inhaling toxic gases that are produced when electrical components or other materials burn in an inflight emergency. The device also prevents or minimizes the risk of spatial disorientation that occurs due to a lack of visibility. The EVAS provides real-time situational awareness of flight instruments enabling pilots to land the aircraft safely.

The EVAS system is becoming increasingly popular in the aviation industry, starting from the mid-2000s. It is widely considered as a solution to inflight smoke issues, which is highly hazardous for both passengers and crew members on board as well.

How does EVAS work?

The Emergency Vision Assurance System (EVAS) is an inflatable hood that is attached to a filter and a hose, enabling access to a clean breathable atmosphere. The device carries a blower unit that continuously filters the air and keeps the air pressure inside the hood higher than the atmospheric pressure, preventing the ingress of smoke.


The air passes through the filtration unit before it enters the inflatable hood. The filters prevent smoke particulates and contaminants from entering the hood, making it a breathable atmosphere to operate in a smoky environment.


The compressor in the EVAS system controls the air flow and maintains a positive pressure inside the hood. The positive pressure prevents the smoke from entering the hood, providing pilots with a safe and clear vision of their flight instruments.

Inflation System

The hood inflates automatically when the pilots pull the EVAS handle. The automatic inflation system reduces the total time required to set up the system. The hood is designed to fit inside the cockpit without the need for significant modifications.

Benefits of EVAS

The Emergency Vision Assurance System has several benefits that make it an indispensable safety feature for airlines.

Enhanced Visibility

By providing pilots with a breathable atmosphere free from smoke and other contaminants, the EVAS enhances pilots’ visibility, enabling them to read and operate the aircraft’s flight instruments more efficiently during an emergency.

Clean Air Supply

The EVAS device provides a continuous supply of clean air maintained at a pressure higher than the atmospheric pressure. The positive pressure inside the hood prevents smoke from entering the enclosure, making it safe and breathable for pilots.

Reduced Risk of Spatial Disorientation

The EVAS system reduces the risk of spatial disorientation, a common phenomenon that could occur due to lack of visibility during an inflight emergency. Spatial disorientation could occur when sensory inputs fail to match physiological responses, leading to fatal consequences.

Easy to Install and Use

The device is compact and easy to install and use, requiring minimal modifications to the cockpit. The lightweight and portable design of the system make it easy to store onboard and are highly beneficial in emergencies.

Cost Benefits

The Emergency Vision Assurance System provides a cost-effective alternative to redesigning airplane cabins to prevent smoke intrusion. The device could be retrofitted on to existing plane models with minimal changes, making it an affordable and practical solution for airlines looking to invest in safety and equipment upgrades.

The aviation industry is continuously evolving with technological advances designed to improve safety, performance, and comfort. The Emergency Vision Assurance System is one such innovation that is proving to be a game-changer in reducing the risk of inflight emergencies due to smoke, dust or fumes. The EVAS is an excellent investment for airlines to mitigate the risks of inflight emergencies and protect pilots and passengers from harm.


  • https://www.boeing.com/commercial/aeromagazine/articles/qtr_3_07/article_02_2.html
  • https://www.aviationtoday.com/2020/06/08/emergency-vision-assistance-system-avoids-spatial-disorientation-inflight-smoke/
  • https://www.flightglobal.com/fleets/less-smoke-screen-more-clear-vision-new-technology-to-keep-the-dirty-air-out-of-the-cockpit/134900.article