prop troubles

[xavtwin]

hi guys,

I fly a C-206 in DRC with a Mc Cauley propeller and I ve got some trouble with the prop.:suspect:

Firstable the blade number1 have a shimmy and leaking lighter ( only on the blade), my mechanical man ( who is not a prop specialist) replace the seal by another one and the trouble stop - no more leak and shimmy -
So after 7 flight time hours it's the blade 3 who is in trouble - no leak but shimmy -

For informations I have no prop vibration and when I check pitch everything seems ok.

Is anybody met this sort of trouble in past.

Thank u

[stevef]

I've worked in the DRC (or Zaire as it was then) and understand the maintenance difficulties but you're asking for trouble if you fly with unauthorised repairs to props, especially those performed without proper literature/tools. I'm not sure what you mean by 'shimmy' but if it's the blade twisting movement in the hub, you're only allowed something like one degree.
Regarding McCauley prop leaks, if you ever see that the oil is stained red, then the aircraft must be grounded. The dye is there to indicate a hub leak, generally caused by cracks.

[SNS3Guppy]

Generally unless it's a propeller overhaul station, opening the propeller to reseal individual blades isn't an authorized repair. Moreover, if one is going to reseal one blade, one should be resealing all blades, and you're into propeller overhaul at that stage.

As stevef noted, if you're seeing dye, you're looking at an impending propeller failure, should you continue to operate the aircraft. Should this occur you stand a high probability of not only shedding part or all of the propeller in flight, but also the engine. If you shed the engine you're looking at catastrophic damage, an unrecoverable CG shift, and the loss of the airplane (and you, with it). Your propeller is a high-stress item, and it's nothing with which to fool around.

Consider the simple act of dressing propeller blades with a file: material removed from one blade must be removed from alll, and we're talking about very small amounts. Imagine addressing a leaking propeller by simply working on one blade...not the right thing to do. We don't simply replace coating or repaint or refinish one blade: it's all, and the propeller should be rebalanced before installation.

The original post was unclear regarding what, exactly, is leaking, and where. With that in mind it's very hard to address the question except for applying general cautions.

[xavtwin]

Thank you for informations,

Whatever, tomorrow I leave DRC for wilson airport nairobi at CMC - If doubt no doubt

SNS3 Guppy, Concerning the leak it's only engine side on blade1 and very light. I do not know from where... like it is very light but suppose it is the red oil.

Overhaul prop is in 800hours, so I spoke with a MAF AMO who said me it 's better to do not wait , because trouble can be worst in 10 hours ou 200?
So we made a little test to see if blade are line up but we saw number 1 has a gap , blade 2 and 3 them are on same line.
thanks

[stevef]

Concerning the leak it's only engine side on blade1 and very light. I do not know from where... like it is very light but suppose it is the red oil.

Xavtwin. I'd say that you've had a lucky escape if it was red-dyed oil that was leaking. That's why there are so many accidents in the Congo: sub-standard maintenance. I've seen it first-hand and it's quite frightening. Anyone with any technical knowledge working on C206s and McCauley props should have been aware of the significance of the oil colour.
Don't wait - talk to the owner and the other pilots, the aircraft mustn't be flown until the problem's rectified.

Were you at N'dolo?