than the cabin. The risk of lung damage is still present, but significantly reduced compared with explosive decompression. Gradual decompression Slow, or gradual, decompression occurs slowly enough to go unnoticed and might only be detected by instruments. This type of decompression may also come about from a failure to cabin pressurization as an aircraft climbs to altitude. An example of this is the 2005 Helios Airways Flight 522 crash, in which the maintenance service left the pressurization system in manual mode and the pilots did not check the pressurization system. As a result, they suffered a loss of consciousness (as well as most of the passengers and crew) due to hypoxia (lack of oxygen). The plane continued to fly due to the autopilot system and eventually crashed due to fuel exhaustion after leaving its flight path. Decompression injuries The following physical injuries may be associated with decompression incidents: Hypoxia is the most serious risk associated with decompression, especially as it may go undetected or incapacitate the aircrew. Barotrauma: an inability to equalize pressure in internal air spaces such as the middle ear or gastrointestinal tract, or more serious injury such as a burst lung. Decompression sickness. Altitude sickness. Frostbite or hypothermia from exposure to freezing cold air at high altitude. Physical trauma caused by the violence of explosive decompression, which can turn people and loose objects into projectiles. At least two confirmed cases have been documented of a person being blown through an airplane passenger window. The first occurred in 1973 when debris from an engine failure struck a window roughly midway in the fuselage. Despite efforts to pull the passenger back into the airplane, the occupant was forced entirely through the cabin window. The passenger's skeletal remains were eventually found by a construction crew, and were positively identified two years later. The second incident occurred on April 17, 2018 when a woman on Southwest Airlines Flight 1380 was partially blown through an airplane passenger window that had broken from a similar engine failure. Although the other passengers were able to pull her back inside, she later died from her injuries. In both incidents, the plane landed safely with the sole fatality being the person seated next to the window involved. According to NASA scientist Geoffrey A. Landis, the effect depends on the size of the hole, which can be expanded by debris that is blown through it; "it would