Power Recovery Washes??
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Power Recovery Washes??
From another thread:
"how many operators carry out regular power recovery washes and plot the results on a trend graph?"
Whats a power recovery wash?
Cheers
The Hedge
"how many operators carry out regular power recovery washes and plot the results on a trend graph?"
Whats a power recovery wash?
Cheers
The Hedge
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The Hedge
As I understand it, in simple terms a power recovery wash is spraying water into the engine intake to wash the accumulated detritus (dust, salt accretion etc.) off the compressor blades and stator vanes, to improve their aerodynamic efficiency.
I'm fairly sure engine manufacturers recommend this be done at more frequent intervals where the aircraft operates in a seaside environment.
I'm fairly sure engine manufacturers recommend this be done at more frequent intervals where the aircraft operates in a seaside environment.
Wrong. A power recovery wash is usually carried out at 50 or 100 hour intervals. It used a chemical (usually Turco or similar) in the wash water.
It's kind of like a "spring clean" if compressor washes are defined as "sweeping the floor". Unpressurised aircraft engines and engines operated in a salt laden environment should be washed daily.
After a power recovery wash improved engine performance should be detected on the engine trend graph.
And incidentally, "compressor washes" also clean the gas generator and power section rotating components.
It's kind of like a "spring clean" if compressor washes are defined as "sweeping the floor". Unpressurised aircraft engines and engines operated in a salt laden environment should be washed daily.
After a power recovery wash improved engine performance should be detected on the engine trend graph.
And incidentally, "compressor washes" also clean the gas generator and power section rotating components.
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Thanks for that.
Just the answer I wanted
BTW Torres,
A couple of Q's:
If the recommended practice (PT6-114A) is to do a rinse "after the last flight of the day", do you then dry motor the engine to expel the H2O? Surely the water doe'nt sit inside the engine overnight.
Or is a morning rinse with drying run (ie engine start) a better idea?
Cheers
Just the answer I wanted
BTW Torres,
A couple of Q's:
If the recommended practice (PT6-114A) is to do a rinse "after the last flight of the day", do you then dry motor the engine to expel the H2O? Surely the water doe'nt sit inside the engine overnight.
Or is a morning rinse with drying run (ie engine start) a better idea?
Cheers
Last edited by The Hedge; 21st Jul 2003 at 15:14.
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Hedge
You will find references to both water washes & power recovery washes for PT6's in AD/ENG/5 Appendix 'A' Aus AD/ENG/5 , and in your case if the -114 is in a Caravan you should check out AD/PT6A/28.AUS AD/PT6A/28
Also table 701 (71-00-00) in your MM. (Sorry no link)
I think you will find your MM requires a drying run at 80% after a wash, but check with your local licensed LAME's & the MM.
TT
You will find references to both water washes & power recovery washes for PT6's in AD/ENG/5 Appendix 'A' Aus AD/ENG/5 , and in your case if the -114 is in a Caravan you should check out AD/PT6A/28.AUS AD/PT6A/28
Also table 701 (71-00-00) in your MM. (Sorry no link)
I think you will find your MM requires a drying run at 80% after a wash, but check with your local licensed LAME's & the MM.
TT
Hedge. You need to carry out a drying run after a compressor wash, as TT says above. We revised our Caravan System of Maintenance to carry out the compressor wash (on -114A's) before the first flight of the day, using the first start as the drying run. Pratt's agreed that process.
There's pros and cons and arguments both ways I guess. Our theory was that carrying out a wash in the morning resulted in a "clean" engine, whereas carrying out the wash at night could result in salty air getting into the engine during the night, even with bungs in place.
But what ever you do, you must, religiously do the following:
Daily compressor washes;
Maintain the engine trend monitoring religiously and have it interpreted by a competent person;
Very regular boroscope inspections;
Buy a spare set of fuel nozzles and change at least every 300 hours;
Have the removed fuel nozzles tested before cleaning and cleaned and overhauled by the engine manufacturer in Brisbane.
Reason for the fuel nozzle change at 300 hours? At around US$300 to clean and overhaul the fuel nozzles (two bucks per flying hour) is cheap insurance against the hot spot damage you could get from a faulty fuel nozzle.
Reason for using Pratt's to overhaul the nozzles? I have seen the extensive damage caused by fuel nozzles cleaned in an inappropriate manner, by a major Australian aviation maintenance company, who were very reluctant to pay for the damage caused.
That bit of cheap advice could save you hundreds of thousands of dollars.
Hedge: You could post your questions on the PPRuNe Engineers and Technicians Forum or contact a Field Engineer from Pratt's in Brisbane and see if they still give away the Pratt's brochure "Turbine engine handling notes for Pilots" or some such title. It was a very useful little booklet.
There's pros and cons and arguments both ways I guess. Our theory was that carrying out a wash in the morning resulted in a "clean" engine, whereas carrying out the wash at night could result in salty air getting into the engine during the night, even with bungs in place.
But what ever you do, you must, religiously do the following:
Daily compressor washes;
Maintain the engine trend monitoring religiously and have it interpreted by a competent person;
Very regular boroscope inspections;
Buy a spare set of fuel nozzles and change at least every 300 hours;
Have the removed fuel nozzles tested before cleaning and cleaned and overhauled by the engine manufacturer in Brisbane.
Reason for the fuel nozzle change at 300 hours? At around US$300 to clean and overhaul the fuel nozzles (two bucks per flying hour) is cheap insurance against the hot spot damage you could get from a faulty fuel nozzle.
Reason for using Pratt's to overhaul the nozzles? I have seen the extensive damage caused by fuel nozzles cleaned in an inappropriate manner, by a major Australian aviation maintenance company, who were very reluctant to pay for the damage caused.
That bit of cheap advice could save you hundreds of thousands of dollars.
Hedge: You could post your questions on the PPRuNe Engineers and Technicians Forum or contact a Field Engineer from Pratt's in Brisbane and see if they still give away the Pratt's brochure "Turbine engine handling notes for Pilots" or some such title. It was a very useful little booklet.
Last edited by Torres; 22nd Jul 2003 at 14:58.
