P-3 Prop blades

[TIMTS]

I took this picture of a P-3 prop blade the other day. This is obviously a somewhat dented blade...
The question is: How much would this affect the aircraft?

http://img.photobucket.com/albums/v381/HeliKen/PPRUNE/SXM027.jpg

[dogcharlietree]

I'm sure that if you looked at the other three blades on the hub, you would find they look very similar.
This is not a dent. It is erosion on the leading edge caused by salt and water from their low level over water operations.
Considering the overall incredible size of the blades (over 4 metres in diameter) this wear is not significant, although I don't remember seeing one with this amount of erosion.

[TIMTS]

Here is the rest of them...
They don't look that bad.

http://img.photobucket.com/albums/v381/HeliKen/PPRUNE/SXM015.jpg

The reason this caught my eye is that I fly helicopters, and I know this sort of damage to a rotor would create some interesting vibrations. I guess this prop would vibrate some as well, but I could be totally wrong...

[Daysleeper]

Youd be hard put to notice any extra vibration. There's already enough to go turn your coffee frothy.:p

The "dent" is probably a stone chip from landing (reverse thrust drags a lot of dust and debries up) the engineers will then have blended out the chip to prevent cracking.
Its very common and there is no overall effect on the aircraft performance.
We had loads of them and only 2 of our aircraft did low level so its not just errosion from salt water.

[MkVIII]

I have a sorta similar Sensenich 2 blader mounted in my den. It had been used for years on a training aircraft operating off a gravel strip, so the engineers CONSTANTLY had to keep dressing back the tips and edges to bring some uniformity to the prop.

I flew the a/c it was attached to a few times, and a degree of vibration in excess of other aircraft in the fleet was noticeable, although that type of a/c vibrated a damned lot anyway!

The prop was finished off one day when a student pilot (a lady of german origin) took it up with an instructor for X-wind circuits. They managed on landing to actually dig the prop in (without any other damage except to the engine). Some weeks later, I saw it in the corner of the engineer's hangar, and after a little talking, it now hangs in my house - kind of an interesting talking point!

[GotTheTshirt]

There is a basic one third rule.
Inner third no damage.
second third some damage ( per the manual)
outer third fairly liberal damage including cropping in some cases up to 2 inches
Main thing is blending which is what you are seeing here to remove any nicks cracks or dings.
It is usually better to remove more material to get a smoother profile.;)

[eng1170]

I've been surprised in the past how much material can be removed from the fan blades in a CFM56 without any increase in vibration. The MM limit's are quite gemerous to say the least.

Eng

[Dengue_Dude]

Sure looks like blending to me.

They used to take some startling lumps out of the blades of the C130s at Lyneham and presumably everywhere else too.

I also agree with the comment about the vibration would have to increase a whole lot for anyone to notice.

I used to run old bangers when I was on Hercules and when leaving the carpark to drive home - it felt like a Rolls Royce.

That should give you some idea.

The missing paint etc IS erosion or particle blasting from the environment these poor s*ds operate in.

[privateer01]

Those are hamilton Standard props on that P-3. Used in conjunction with the Allison T56 (now RR) or 501 if you prefer.
On a Convair 580/5800 they are 13' 6" in diameter and you can really file down the tips.