C17 Aircraft Cleaning Trial
C17 aircraft flight maintenance crews regularly face challenges with cleaning and removing various soiling found on aircraft. They previously used two products, a solvent and an aqueous cleaning solution, which were unable to completely and satisfactorily clean and remove the debris from the airplanes.
The C17 aircraft crew needed more efficient cleaning products that saved time and labour costs. The products must also adhere to work health and safety standards and comply with environmental regulations.
Envirofluid conducted a trial clean of a C17 Cargo aircraft with the help of the maintenance crew. The trial was conducted by the client and Ben Ohlmeyer and Peter Kearney from Envirofluid.
The routine cleaning equipment included a collection of telescoping handled brushes and 3M scrub pads, buckets, overalls, safety goggles, chemical safety gloves, pressure washing and recycling reservoirs and pumps, sponges, paper wipes, scissor lifts, cherry picker and man lift and ample water hoses and sprayers. The trial was conducted as a side by side comparison using the two products previously used by maintenance crews versus Triple7 Aircraft & Metal Cleaner and Purasolve CGA.
Triple7 Aircraft & Metal is a high-tech super concentrated aircraft cleaner and degreaser. It is powerful, safe and suitable for a wide range of aircraft surfaces and materials including metals, acrylics, rubber, paint and vinyl. The product is safe for soft metals and protects against tarnish and oxidation.
Purasolve CGA is a plant-based formulation with high solvency power which is environmentally responsible and user-safe. It is the ideal solvent for removing a variety of soiling including carbon, gum and adhesives, silicone, dried lubricants and fuels, paraffin, wax, urethane sealants, and more. It has no HazChem rating and satisfies regulatory agencies such as EPA and WHS.
The intended plan was to wash the C17 aircraft with previously used products on one side (starboard), and Envirofluid products on the other side (port), and to compare the cleaning performance of the two sets of products using a combination of hand-applied and pressure washer applied cleaning and solvent solutions. The cleaning commenced with the understanding that the current products would be applied to the aircraft initially as a solvent and then an aqueous solution, followed by a water rinse – as would be the normal method of immiscible solvents and aqueous cleaners. This was also the intended cleaning procedure for using Triple7 Aircraft & Metal and Purasolve CGA, both of which were previously tested and certified according to the client’s approved cleaning standards.
The aircraft was wet down and the cleaning commenced, starting with the landing gear on both sides and at the nose. At first, the products were applied separately with no apparent overlap between them and the nose gear being entirely cleaned with the new Envirofluid products, first with Purasolve CGA, followed by Triple7 Aircraft & Metal. Immediately, the crew commented that the new products worked especially well and that tough soils such as dried carbon soot and hydraulic fluids that were never previously removed were now easily eliminated.
The previous products were then combined as a temporary emulsion by the team using them. The team leader commented that neither of the existing products worked very well but combined together, achieved acceptable results. Additionally, it was mentioned that the two existing products had to be continually mixed by the pump or they would fall apart very quickly. Similarly, the Envirofluid products were not intended to be combined since they would not mix completely and would separate over several minutes if not continually mixed into a suspension. However, it was agreed to carry out a trial mix of Triple7 Aircraft & Metal and Purasolve CGA to surprisingly outstanding results.
Quite quickly the combined Envirofluid products were outperforming the earlier blended mix of the existing products and removing some stains easily, even those that the earlier blended mix could not remove. Even bird droppings, which they stated took some 20 minutes of scrubbing to remove, were not a problem for the blended Envirofluid products. Other examples of soiling that were quickly eliminated included miscellaneous hydraulic and brake fluid stains, hand prints, rubber and fuel stains, and lubricants, greases, stains and carbon soot.
An explanation for this is that although the Triple7 Aircraft & Metal and Purasolve CGA are not fully miscible, having them in the same container and being applied together simply reduced the time it took to switch between two products, and also prevented the solvent from drying out too fast. This was supported by extensive trials throughout the day – together in the same applicator as they worked extremely well together.
The mix of Envirofluid products also removed a good deal of the hydraulic oil stains that had a tendency to blow out onto the engine cowlings, the exhaust surfaces, and the underside of flaps and fuselage and had not been previously removed with the existing products.
At the end of the day, the conclusion was obvious: the Envirofluid products removed the difficult soils on the C17 more efficiently and more thoroughly, albeit with the added convenience of combining the products because of the available recirculating pump in the pressure washing assembly. Additionally, the new products do not create a forced emulsion and thereby greatly improve the processing of wash wastewater and hydrocarbon/soot recovery before entering the wastewater tank.