What could cause a low-pressure compressor first stage blade of a low-bypass turbofan engine to bend forward?
I also noticed rotor path rubbing in the 9 to 12 o'clock portion (while usually this can happen only in the 6 o'clock area).
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1$\begingroup$ You should provide more context to ease the reading of your question. $\endgroup$– Manu HCommented Nov 28, 2016 at 9:58
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3$\begingroup$ also, can you post a picture? $\endgroup$– FedericoCommented Nov 28, 2016 at 10:01
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1$\begingroup$ Not a great deal I think is the answer so if you have one it's a bit worrying. How much is it bent by and where (tip/root)? Pictures would be very helpful! $\endgroup$– Notts90Commented Nov 28, 2016 at 13:00
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$\begingroup$ Is it specifically the leading edge of the tip of the blade that is bend forward? $\endgroup$– DeltaLima ♦Commented Nov 28, 2016 at 16:21
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$\begingroup$ And welcome to Aviation.SE, Anso. $\endgroup$– DeltaLima ♦Commented Nov 28, 2016 at 16:22
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1 Answer
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Forward bending of the first stage of the low pressure compressor is usually associated with (soft) Foreign Object Damage (FOD).
Ice and/or large quantities of snow in the engine intake will typically cause forward bending of the leading edge of the tip of the blades.
Damage to GE CF680C2 turbine engine compressor fan blades after snow/ice ingestion
Source: Flight Safety Australia
Damage to Turbomeca gas turbine Arriel 2B turbine engine compressor blades after snow/ice ingestion
Source: Transport Safety Board of Canada, aviation accident investigation report A12P0008
answered Nov 28, 2016 at 17:19
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$\begingroup$ Thank you for the answer. There is no sign of FOD though. the bending of the blades is almost same as your first image. I suspect that the abradable coating in rotor path came chipped off (as a large piece, but it cannot be confirmed because the rubbed area doesn't look so) because of any ovality in casing and it might have struck in between blades and rotor path. Total 5 blades got bended. first in the five got more damage and the following ones got less bend. $\endgroup$ Commented Dec 7, 2016 at 10:04
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1$\begingroup$ @AnsoMamachan: Blade bending is a sign of FOD. $\endgroup$– VikkiCommented Nov 16, 2019 at 21:52