FOD or not to FOD
05-17-2008, 08:51 PM
#1
FOD or not to FOD
Hello gang,
I was wondering if anyone notices a performance change when they put a FOD screen on their engine? Last season, I added a FOD to my JJ1400. It seemed that I lost a bit of thrust. I needed 3/4 throttle to apparently fly the same as 2/3 throttle before adding the FOD screen. Anyone else observe performance changes with the addition of a FOD screen?
DW_Crash
I was wondering if anyone notices a performance change when they put a FOD screen on their engine? Last season, I added a FOD to my JJ1400. It seemed that I lost a bit of thrust. I needed 3/4 throttle to apparently fly the same as 2/3 throttle before adding the FOD screen. Anyone else observe performance changes with the addition of a FOD screen?
DW_Crash
05-17-2008, 09:02 PM
#2
RE: FOD or not to FOD
I noticed about a 40 degree increase in EGT for full thrust on a given typical day at density altitudes of 5000 or higher with a FOD screen added - it may be less critical at low altitudes. This is with a Jetcat P-60SE and a TAM FOD Screen. The increased EGT could limit thrust of course if you have a marginal engine and you are running up against max EGT during acceleration or high thrust settings. But my feeling is I always like the safeguard of a FOD screen, and I run it. To date it has never limited my max thrust at full throttle as my engine tends to have a good amount of head room at typical full throttle thrust settings even on the hot days with density altitudes above 8000 feet.
05-18-2008, 12:59 AM
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RE: FOD or not to FOD
FWIW
You should not see any change in thrust with a FOD screen. The only changes that may arise are a higher SFC and possibly higher EGT. Both should be negligible.
You should not see any change in thrust with a FOD screen. The only changes that may arise are a higher SFC and possibly higher EGT. Both should be negligible.
05-18-2008, 07:19 AM
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RE: FOD or not to FOD
ORIGINAL: causeitflies
The size of the FOD screen and in particular the size of the mesh will affect how much thrust is lost.
The size of the FOD screen and in particular the size of the mesh will affect how much thrust is lost.
And I guess how much you save!
05-18-2008, 12:11 PM
#11
RE: FOD or not to FOD
Last weekend I was spotting for a Boomer XL.
At the end of the flight he pulled off the hatch and then shut down the turbine.
As the turbine wound down, a clump of grass fell fro the bottom of the FOD screen.
This jet has screen in the intakes, yet a clump of grass found its way to the turbine inlet.
Yup, I run a FOD screen to.
At the end of the flight he pulled off the hatch and then shut down the turbine.
As the turbine wound down, a clump of grass fell fro the bottom of the FOD screen.
This jet has screen in the intakes, yet a clump of grass found its way to the turbine inlet.
Yup, I run a FOD screen to.
05-19-2008, 02:40 PM
#14
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RE: FOD or not to FOD
ORIGINAL: drdoom
Turbojet $2000.00 to $9000.00 , FOD Screen $20.00,
Turbojet $2000.00 to $9000.00 , FOD Screen $20.00,
Sara Parish
Wren Turbines
05-19-2008, 04:03 PM
#17
RE: FOD or not to FOD
I think the likelyhood of damage from rubbish sucked into the engine is very much overstated. The guy I fly with has only used FOD screens on the engines which came with them as standard (some of hiis Wrens) and has been flying for years both from our rough grass strip & at organised jet flys from tarmac. No problems at all.
At most jet flys I've attended probably 90% of the models do not have screens & I don't think I've ever seen a problem from injestion of debris.
I feel they are like a fire extinguisher, 99% of the time they just sit around doing nothing.
Me? I have them on all of my engines for that 1% of the time that will break your heart & wallet. - John.
At most jet flys I've attended probably 90% of the models do not have screens & I don't think I've ever seen a problem from injestion of debris.
I feel they are like a fire extinguisher, 99% of the time they just sit around doing nothing.
Me? I have them on all of my engines for that 1% of the time that will break your heart & wallet. - John.
05-19-2008, 05:36 PM
#19
RE: FOD or not to FOD
ORIGINAL: tamjets
Mark,
I got that cover.
ORIGINAL: causeitflies
All manufacturers should follow Wren's example or at least offer the option.
All manufacturers should follow Wren's example or at least offer the option.
I got that cover.
05-19-2008, 08:27 PM
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RE: FOD or not to FOD
I have one for the P-200 air hog that the engine does not even notice and use it EVERY time the engine is started or stored. If you want filtered but maximum mass air flow ,you need to increase the area of the screen, the hole size or both. HINT: a piece of wire mesh waste basket or pencil holder you can get at the stationary store, properly secured to the intake, is far better than nothing. It may not keep out small sand, but will keep fingers, tools, sticks, stones, candy wrappers, condoms and grass out of places they should not ever go.
bob
bob
05-19-2008, 09:25 PM
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RE: FOD or not to FOD
ORIGINAL: lugebob
I have one for the P-200 air hog that the engine does not even notice and use it EVERY time the engine is started or stored. If you want filtered but maximum mass air flow ,you need to increase the area of the screen, the hole size or both. HINT: a piece of wire mesh waste basket or pencil holder you can get at the stationary store, properly secured to the intake, is far better than nothing. It may not keep out small sand, but will keep fingers, tools, sticks, stones, candy wrappers, condoms and grass out of places they should not ever go.
bob
I have one for the P-200 air hog that the engine does not even notice and use it EVERY time the engine is started or stored. If you want filtered but maximum mass air flow ,you need to increase the area of the screen, the hole size or both. HINT: a piece of wire mesh waste basket or pencil holder you can get at the stationary store, properly secured to the intake, is far better than nothing. It may not keep out small sand, but will keep fingers, tools, sticks, stones, candy wrappers, condoms and grass out of places they should not ever go.
bob
Condoms?
Dude.. where do you fly?
Don
