Making a splash by brushing up on cleaning techniques

Tough engine cleaning jobs used to be tackled with ground up walnut shells and apricot pits. Not unreasonably, a foaming agent that does the same job is particularly welcome.

Wash this space: Etihad Airways engineers deploy GE’s 360 Foam Wash system on aircraft on the apron at Abu Dhabi International Airport. Picture: Etihad Airways.

GE Aviation and Etihad Airways enhanced their ‘green’ credentials with the introduction in February of GE’s ground-breaking waterless 360 Foam Wash jet engine cleaning system.

By deploying the system to optimise performance on its GE90 and GEnx-1B engines, Etihad stands to reduce the CO2 emissions of its Boeing 777 and 787 fleets by 7,000 metric tonnes in 2021.

The new foam wash initiative – the first joint GE and Etihad project under the Etihad Greenliner programme – has far-reaching implications. Paul Kear, Etihad’s senior vice-president technical, called it “a prime example of industry collaboration that will have a significant impact on Etihad’s efficiencies and provide a case study for the broader industry”.

The 360 Foam Wash system is a proprietary solution and process approved and licensed for use on engines including the GE90, GEnx, CF34, CF6 and GP7200.

Etihad Airways is the first airline licensed for GE90 engines, and the first licensed for multiple GE engine programmes.

Etihad’s collaboration in the trial process was important to the product’s development. Jean Lydon-Rodgers, vice-president and general manager of GE Aviation’s after-market strategic solutions, said: “We are learning more than ever before about how our engines operate and how they respond in hot and harsh environments. Our longstanding relationship with Etihad has been integral to that process.”

Earlier, Qatar Airways (QA) became the first airline licensed to use the 360 Foam Wash on the GEnx engine, following trials in Doha. It currently uses the system on both the GEnx-1B powering its Boeing 787 fleet and the smaller GEnx-2B on its Boeing 747s.

A spokesman said QA is trialling the technology on other parts of its fleet.

Emirates is also licensed to use the technology on its GE90 engines.

GE’s 360 Foam Wash involves injecting a specially formulated, proprietary solution into the engine to remove dust and dirt particles. Engine performance benefits from a reduction of deposits, lower exhaust temperatures, and improved engine compressor efficiency. The result is lower fuel consumption and increased engine time on wing.

The system is self-contained, allowing it to be used inside maintenance hangars or outdoors.

Meanwhile, Lufthansa Technik (LHT) recently introduced an upgrade of its “revolutionary” Cyclean Engine Wash procedure for the Pratt & Witney PW1100G family of engines.

It adds to the list of common engine types covered by Cyclean, including CFM56, V2500 and CF6, as well as latest-generation engines such as LEAP-1A/-1B, GE90, GEnx and the Rolls-Royce Trent family.

An LHT spokesman said engines operated in the Middle East often need to be washed more frequently than in other regions due to the salty and sandy operating conditions. This puts a premium on the reliability and speed of turnaround of engine washing systems.

LHT says the Cyclean procedure is designed to wash an engine in just under 45 minutes, even directly at the gate.

It uses just half the water, or less, needed by other methods. A waste water collection system, specified for each engine type, captures all the water used, to comply with environmental standards.

Benefits of the system include an increased exhaust gas temperature (EGT) margin and a reduction in fuel flow, longer average on-wing time, and lower maintenance costs throughout the entire life cycle of an engine.

Fixed and mobile units are in operation throughout the MRO’s network, including Middle East stations.

Elsewhere, researchers are studying other novel, environmentally responsible methods to keep engines running efficiently. One such is Safran’s Maclean project, funded under the European Commission’s life programme, which hopes to industrialise two complementary cleaning processes, cryogenics and laser, starting with helicopter engines.

Cryogenic cleaning involves projecting dry ice (solid-state CO2) on to a surface using a high-pressure air system, similar to sandblasting. During the process, the CO2 disperses through sublimation.

Laser stripping uses powerful light energy to clean parts without changing the underlying material and its coating.

Safran says both technologies are already used in other industries, including marine and automotive, but need the appropriate approvals before they can be used in aerospace.

Chuck Grieve reports.