Compressor rinsing
 

By this I mean water rinsing, not chemical washing. Does anyone use anything other than ordinary mains tap water for engine rinsing? There's a very good reason for asking.....

When I preforming many many comp and turbine washes on PT6
engines which did Scottish Fisheries work at low level off the coast I used tap water but had the water checked out first to see if it was soft or hard. I did however when away from base used the drinking water that comes in the containers you find in airports, offices etc.

For a comp wash
When suds are used. The rinse is demineralized water
When washing with “hot water”
Wash/Rinse cycle both use demin water..
Hope this helps

But then again it may be different in the southern hemispere..

suggest you consult your engine maintenance manual, they generally give the minimum standards of water quality required

Interestingly, we used to use tap water daily on a previous model of the same engine series, with the full knowledge of the contracted maintenance organisation which is also an accredited agent of the engine supplier. For 8 years we never had a contamination problem despite operating low level close to the sea.

When we replaced the old aircraft with one powered by a later model of the same engine we asked if we could continue that practice and were told we couldn't; not because of the water but because it's technically more complex so chemical washes every 50 hours would be acceptable. Now that the UK fleet is showing signs of contamination the manufacturer has decided a daily wash with distilled or deionized water is the only way.

I'm not asking for advice on what to do as we can handle that side of things, I'm only interested in the general practice.

Any more observations?

Qantas use hot demineralised water for compressor washes on their fleet.We have never been allowed to use tap water.

We used to use a combination of detergent and cold demineralised water but they reckon that the hot water gives a better result.We have tried combinations of all.

Apparently it gives a 0.2% reduction in fuel burn and 20degree EGTM shift after each wash.

Virgin Blue in Australia uses filtered tap (mains supplied) water for the gas path washes.It is the same water that is supplied for potable water on the aircraft (used at the temperature the mains deliver it at).

Compressor washes
 

After reading all your posts I set about washing the compressor on my helo... I have one question... HOW THE HELL DO I GET IT INTO MY TWIN TUB??;)

Another issue has cropped up recently - what do you do with the resultant water contaminated with whatever you wash out of the engine?

The Environment Agency probably won't grant you discharge consent - if you let it run down a drain or onto the ground you could be prosecuted for a pollution offence.

The only legal method of carrying out this procedure that we can see at the moment is to catch ALL of the water coming out of the engine and have it taken away by a licenced waste contractor and disposed of properly.

Incidentally, during aircraft washing procedures at LGW, where we have special interceptors to prevent the runoff getting into the groundwater and local water courses, we've found significant traces of cadmium and magnesium. A/c manufacturers tell us this must mostly have come from undercarriage components. All this contamination has to be disposed of at considerable cost.

Cheers,
TheOddOne