Just browsing the COPA magazine, they briefly mention
“Ten- year propeller overhaul: we are looking toward new data to reintroduce the topic with Transport Canada”
I think in the states it’s time on prop limit.
What about the rest of the world ? Is Canada a special place that props go flying apart after 10 years ?
Re: 10 Year Prop Overhaul Canada
Posted: Thu May 12, 2022 10:37 pm
by trey kule
Of course not.
They fly apart at 10 years and one day. That is why the limit of 10 years.
The life limit was determined by TC after a gender inclusive, equal rights assessment that Canadians expect and deserve.
What! Didyou think they just arbitrarily pulled that 10 year limit from out of the air.?
Re: 10 Year Prop Overhaul Canada
Posted: Thu May 12, 2022 11:35 pm
by Slick Goodlin
Wait, what? All props?
Re: 10 Year Prop Overhaul Canada
Posted: Fri May 13, 2022 12:07 am
by Nark
Jokes on you guys: the Twin Beech’s Ham Stan props are 5 years, so I guess it’s 10 years per airplane.
Thankfully I wasn’t dumb enough to buy the Spruce Goose.
Re: 10 Year Prop Overhaul Canada
Posted: Sun May 15, 2022 3:42 am
by anofly
All constant speed props..
Data from a respected canadian prop shop , shows most props on imported american planes, that are often way past 10 yrs since overhaul, regularly fail inspection criteria for overhaul...
Re: 10 Year Prop Overhaul Canada
Posted: Mon May 16, 2022 3:48 pm
by digits
What's the weakest spot on constant speed props? Let's say you keep running them indefinitely, what kind of failure mode is to be expected first?
Is it a matter of not holding RPM properly anymore, desintegration of the blade due to centrifugal forces, the whole thing exploding, something else ... ?
Re: 10 Year Prop Overhaul Canada
Posted: Mon May 16, 2022 6:48 pm
by Squaretail
The few I have seen fail their inspections had too much filed off of them. Props run on gravel if improperly handled can take a lot of wear.
Re: 10 Year Prop Overhaul Canada
Posted: Tue May 17, 2022 1:38 pm
by Nark
I have an avoid range of 1850-2000 RPM (I think, it’d have to check the POH) on the Beech. So there’s is harmonic resonance in there too.
*caution thread derail*
Even though you asked about constant speed, my Stinson’s MET-L prop had an avoid range as well (2100-2300 RPM if is can recall).
Ground resonance is a pretty big thing for helicopters too (depending on the make up of the hub). A pretty well known example is in the opening scene to a McGyver episode when they get dropped off on the roof of an LA skyscraper.
Re: 10 Year Prop Overhaul Canada
Posted: Thu May 19, 2022 2:09 am
by anofly
Well the one failure mode that created an AD on steel hub Hartzell props , had to do with corrosion . The props might be 20 years plus since overhaul in the usa , and they shed the odd blade....
They improved the blade clamp design to hold them together.... very small corrosion pits will condem a blade to scrap...