Aviation Medicine Quiz – Hypoxia

Before we understand the basics about Hypoxia, please answer to the best of your knowledge and understanding the following questions pertaining to Hypoxia in aviation. Continue reading

Flying into thin Air: Understanding Hypoxia

Undoubtedly cabin pressurisation and oxygen systems have allowed unhindered aviation activities, with a caveat though – never to cross the altitude beyond the capabilities of the system on board. Thus, commercial aircraft fly maintaining a cabin pressure of 6000-8000 ft, and unpressurised small aircraft mostly operate below 10000 ft. Combat aircraft may have a higher service ceiling, but their onboard oxygen systems, invariably, are ‘get-you-down’ devices only. Thus the threat of hypoxia is ever present with accidental loss of cabin pressurisation or when flying beyond the mandated altitude. Although of major interest in military aviation, hypoxia remains a threat in civil aviation as well. Remember the crash of Helios Airways Boeing 737-300, on August 14, 2005 in Greece, where 6 crew and 115 passengers perished due to lack of pressurisation.

So, what is HYPOXIA?  Continue reading

Flying into Thin Air: Neurological Effects of Hypoxia

The most important effects of hypoxia is on Central Nervous System (CNS) and vision. This insult to CNS which affects the performance in flight varies as per the altitude and the resulting stages of hypoxia. The effects are discussed as per the stages of hypoxia. Continue reading

Flying into Thin Air: Preventing Hypoxia

Technological improvements in reliability and performance of cabin pressurisation and Oxygen delivery systems has greatly reduced the incidents and accidents due to hypoxia. Yet, incidence of hypoxia in flight still occurs due to lack of vigilance, mechanical failure of equipment, improper indoctrination or improper use of oxygen equipment.  Continue reading

Hyperventilation – Confusing the Devil with Hypoxia

An ab-initio military pilot on a familiarisation sortie to the sector with his Instructor, was finding it difficult to see the defined waypoints. This was due to thin clouds below, through which the Instructor could see and point out the features, but the rookie pilot, flying his first sortie in that sector, just could not visualise it. His anxiety of sector briefing sortie was compounded by apprehension of inability to seeing what he was supposed to see on ground. He started to feel numbing sensations at his fingers and toes with wet palms and dry tongue. He informed the Instructor of his not feeling ‘so well’. Instructor found him breathing rapidly without any reason. The sortie was aborted. The trainee narrated his plight, which was corroborated by the instructor, who informed the flight surgeon about the sortie profile, weather conditions and the state of the trainee pilot. The trainee was hyperventilating. He was explained about hyperventilation in detail by the flight surgeon. The reassured trainee pilot  successfully earned his wings a few months later.” Continue reading