Liquid oxygen is an untapped opportunity in the rotorcraft industry – it can reduce weight and operating costs and boost safety and capacity.  Bob McKeown, Essex Industries tells FINN more.

With a long background in liquid oxygen, Essex Industries is now bringing the technology to the rotorcraft industry.

Essex entered the cryogenics market in 1963 and has delivered over 100,000 liquid oxygen (LOX) systems for military and commercial applications.

In 2010, Essex assembled a complete Battlefield Oxygen Sustainment System (BOSS) as part of the US Air Force Guardian Angels Integrated Oxygen System. The BOSS provides a medevac team with equipment that works together to deliver oxygen to the patient both on the ground and during transport as well as devices to generate LOX and refill equipment in the field.


The technology developed for military LOX systems has led Essex to now offer similar systems in the commercial medevac marketplace.

McKeown said: “Typically, and certainly throughout Europe, people use high-pressure cylinders. Liquid oxygen systems are low-pressure, [holding] just 70 pounds per square inch.”

He explained: “The system builds up pressure of its own and as that pressure builds up, the liquid turns back into gaseous oxygen, then pushes out through the plumbed system into a heat exchanger, which warms the oxygen further, making it comfortable for the patient to breathe.”

Helicopter Emergency Medical Services (HEMS) is a key market for LOX, especially in Europe, says McKeown.

“The HEMS market uses LOX because of the advantages that it delivers,” he said. “It helps to reduce aircraft weight because it weighs less than an equal amount of high-pressure oxygen, and it also gives you more space in the aircraft because multiple cylinders take up a lot of space. This is a relatively small system by comparison.”

He added: “Within the next 12 to 18 months, we’ll make the product available. Right now, Essex is in the process of obtaining CE marking, which is, of course, required in Europe. While we’re doing that, we would like to find partners, both operators as well as completion centres, that want to work with us to bring liquid oxygen to Europe.

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