Forward bended Fan Blades
 

Happened to me today on a Challanger 605.
During Pre-Flight Check found 2 Fan blades bended forward on the tips.

Had this already 2 years ago. Nobody can really tell me the reason, why this can happen.
What do you guys think ? Icing ?

Thank you

Water generally causes the fan blade tips to bend forward.

If the intakes are not cleared of any standing water before start up, it will sit there until the engine RPM reaches a level where the water gets drawn into the fan or compressor, whereupon the rotating fan blades suddenly have to pass through the increased density of the water in comparison to the air, and as a result the tips bend forward

:ok:

D W, I`d get an engineer to check displacement of tips,,can cause vibes or stall if outside limits...

Tips, ??

leading edges or trailing edges??

Post a photo and all will be revealed

Most likely ice shed off a centerbody, but photos would confirm elimination of inlet or other fan blades them selves.

It's all in the vectors of a free body being ejected tangentially in an airstream vs one that is "sucked" in.

All engines would be threatened the same way at the same conditions so it should not be taken lightly.

Hi guys.
Thank you for your replays so far.

Here is one of the photos. And by the way, the outside temp upon engine start was positiv so i dont think the Blades where frozen to the acoustic liners.

https://dl.dropboxusercontent.com/u/35814165/image1.JPG

And why was this thread moved out of the tech section ?????

Looks like FOD to me.

Its ice

If only one blade it could be from anywhere and just a random intersect

If more than one looks like this, it's probably from the center body.

If more than one aircraft it's time to review your engine runup procedures in blowing snow with the pilots