Novel two-stage filter technology: Aqua free and Lufthansa Technik cooperate

Lufthansa Technik AG and water hygiene specialist Aqua free GmbH have joined forces in order to improve – in the future – the quality of potable water onboard commercial aircraft. Based on state-of-the art medical technology, the jointly developed two-stage water filtration system PuriFLY ensures the onboard water quality at a lower price point compared to classical filters.

Increased quality and hygiene for potable water onboard

LH Technik AG employees are testing the PuriFLY. Best possible drinking water quality on board, even at an altitude of 10,000 metres (copyright: Lufthansa Technik AG)

Waterfilter PuriFly removes 99.99999 % of all known germs and bacteria. It can easily be retrofitted in most existing commercial aircraft types. This can significantly reduce the cost of complying with stringent drinking water regulations.

Current situation: Potable water filters are using activated carbon – thus neutralize the chlorine in the tap to enhance the taste. At the same time, they do a water filtration through the property of porosity of the activated carbon. In addition to the regular filter change, additional cleaning measures are also necessary.

Unlike these conventional filters, PuriFLY adds a second filtration stage that utilizes an hollow fibre membrane with extremely small pore diameters (in addition to activated carbon). This filtration stage holds back all particles larger than 0.2 µm and removes water bounded bacteria and other particles. This achieves a reliable bacteria retention of 99.99999 %, which corresponds to the standard of medical sterile filters (7-log stages).

“This new partnership with Lufthansa Technik innovatively combines our know-how in medical technology and their expertise in aircraft systems", said Holger Eggert, Head of Product Management and Business Development at Aqua free GmbH.

"The puriFLY filters ensure the onboard water quality at lower cost and less waste", adds Torben Biehl, Head of Aircraft Components in Lufthansa Technik’s Original Equipment Innovation business unit. “Especially in these challenging times, they provide a valuable contribution to the demand for increased hygiene in our everyday life.”

The separation of chemical and mechanical filter stage, PuriFly needs less filter changes and reduces the effort for additional cleaning, resulting in reduced cost for the operator. PuriFLY-filtered water fulfils the same - extremely high - hygiene standards of sterile water filtration that can otherwise only be found in hospitals.

PuriFLY: Enabling the best drinking water quality on board aircraft (copyright: Lufthansa Technik AG)

High End Innovation in Drinking Water Quality in Aircraft

Compared to conventional technology, the new filters optimize the water flow rate and save weight as an additional contribution to reduce costs and waste. The puriFLY filter cartridges are fully certified with an EASA Form 1 and come in exactly the same size than the conventional active carbon filters used today.

They can be easily retrofitted into the existing water filtration systems in almost all commercial airliners utilizing only a minor change certification obtained through Lufthansa Technik with no additional modifications to the aircraft necessary.

The first filters are already flying in large VIP and government aircraft and are now made available to commercial aircraft operators worldwide.

Holger Eggert
Leiter Product Management

h.eggert @
Tel. +49 (0) 40-468999-761