Lufthansa Technik will use dry ice, rather than water, for on-wing engine-washing procedures from 2019.

The German MRO provider has developed the process over several years and filed a number of patent applications for it.

LHT says the use of dry ice – solidified carbon dioxide at -78.5°C (-109.3°F) – will reduce the time required to wash an engine to 30min, and enable the procedure to be conducted in sub-zero temperatures.

Previously, the MRO provider did not conduct its water-based "Cyclean" procedure in temperatures below 5°C because residual water could freeze in the engine core.

Under the new process, dry-ice pellets are shot into the core via a blasting system. They evaporate on impact with the engine's components, leaving no residue behind.

LHT says the impact of the ice-cold pellets – which measure a "few millimetres in size" – dislodges contamination from components in the engine's gas path.

The blasting system is installed on a mobile scissor lift and is suitable for "all engine types, regardless of their size and height", LHT says.

It adds: "There is no need to fasten any pieces of equipment to the engine or to perform a run-up after the engine has been washed."

Conventional engine-wash systems have water-spray devices, typically fixed to the air intake or to the fan's spinner.

LHT says the carbon dioxide used in the cleaning process is a byproduct of oil refineries and fertiliser production plants. "No additional carbon dioxide has to be generated," it notes.

Project manager Dirk Deja states that LHT will be "the first MRO provider to offer engine washes with dry ice".

LHT adds that its water-based engine-wash procedure will continue to be operated.