Prop Nick
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Joined: Mar 2008
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From: Inside CAS
Can't recall exact prop type, but it's a light aircraft (2750lb) single engine Hartz. CS Prop. Nick is prob 3/4 toward tip on leading edge (edge which picks up the bugs?).
Joined: Jun 2003
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From: EuroGA.org
You need to get a qualified engineer to look at it. It's probably OK if within the outermost 1/4 of the blade but if it is within the innermost 1/3 that is a lot more dangerous.
In general, nicks of this depth can be 'dressed out' with a file; a lot of metal has to be removed because the prop edge has to be restored to a smooth curve to minimise sharp surface transitions which concentrate stress and could cause a crack to propagate. The filed area is then smoothed/polished with emery paper, gradually using a finer grade until it is very smooth.
A 3mm deep nick results in the removal of quite a lot of metal by the time it is done properly, and the prop should be dynamically balanced afterwards.
This is the price one pays from operating from runways/taxiways covered in stones e.g. Elstree.
Eventually the prop ends up below manufacturers limits and has to have new blades put in, or be replaced if fixed pitch - expensive!
In general, nicks of this depth can be 'dressed out' with a file; a lot of metal has to be removed because the prop edge has to be restored to a smooth curve to minimise sharp surface transitions which concentrate stress and could cause a crack to propagate. The filed area is then smoothed/polished with emery paper, gradually using a finer grade until it is very smooth.
A 3mm deep nick results in the removal of quite a lot of metal by the time it is done properly, and the prop should be dynamically balanced afterwards.
This is the price one pays from operating from runways/taxiways covered in stones e.g. Elstree.
Eventually the prop ends up below manufacturers limits and has to have new blades put in, or be replaced if fixed pitch - expensive!
Joined: Feb 2002
Posts: 577
Likes: 2
From: Inverness-shire
Have a look in
www.hartzellprop.com
or google "Repair metal propellers" which will give you a direct run to the right spot on the Hartzell site.
The good news is that they are talking about 3/16" as a maximum allowable nick which can be dressed out, so you should be in with a chance.
The bad news is that the permitted allowances (depth and location) on the actual prop concerned will have to be checked and then dressed out by a and signed off by a competent person
www.hartzellprop.com
or google "Repair metal propellers" which will give you a direct run to the right spot on the Hartzell site.
The good news is that they are talking about 3/16" as a maximum allowable nick which can be dressed out, so you should be in with a chance.
The bad news is that the permitted allowances (depth and location) on the actual prop concerned will have to be checked and then dressed out by a and signed off by a competent person
Joined: May 2002
Posts: 237
Likes: 5
From: UK
[The bad news is that the permitted allowances (depth and location) on the actual prop concerned will have to be checked and then dressed out by a and signed off by a competent person]
Bad news eh! Would it be good news if the damage was assessed, dressed out and signed out by an incompetent person then?
Bad news eh! Would it be good news if the damage was assessed, dressed out and signed out by an incompetent person then?
