freakingfast

My Feedback: (3)

There I was, enjoying the speed and turns of my YS 45 RE powered Diamond Dust as I've done hundreds of times when all of the sudden I hear this very loud noise. It sounded like flutter times ten and higher pitched. The plane was about 300 feet away, and for an instant I thought the sound was from something else much closer because the sound was so power-full, but the direction told me my plane was in trouble. I killed the engine and the noise quit after a moment. As the dust glided in for a landing I was expecting to see flapping shards of Ultra coat or some indication of what had happened, than I saw it, only a single blade. The thing had thrown a blade and it’s still in one piece and flying! After a perfect landing I did a complete inspection and found only the four engine mount screws has loosened. The screws were tightened and a new prop was mounted. I later flew the plane two more times and found no problems with it. The prop was a 9x9 APC sport rated to 21,000 RPM. The engine turns 16,300 on the ground and I seriously doubt it would unload to 21K. The prop may have gotten damaged by snagging on deep grass from several flights before. I will look over the hub area or replace the prop in the future if there’s ever any question and god's sake stay out of the prop arc!

Lucky this time!

combatpigg

My Feedback: (3)

FF.....good looking engine and plane combo. Looks like the 2 were made for each other.
Look out for white stretch marks around the prop hub, they are a tip off. My Webra .50 threw a 9x9 APC blade and it was running below the props' redline. Imagine getting hit at close range..[&o]

Troy-RCU

My Feedback: (1)

Wow, you are lucky and should immediately head to Vegas
That's pretty amazing it didn't shake the airframe apart mid-air. Belly lander airframes like the 'Dust will abuse props so it's another reason never to allow someone to stand near the prop arc or in front of the motor when running. I cringe every time I find myself in line with someone else's spinning prop.

Methanolover

Funny, I noticed theese strtchmarks yesterday, both blades , but not near the hub . Took prop ,9x8 C-2 hub[X(], off the Jett SJ-.50, black muffler , and took some pics while bending the blade further and further until it broke.

Rudeboy

WOW!

That is not a "stretch mark"... that thing was broken from the start!

These stretch marks look different: they are like whitish spots, but not clearly outlined like on your prop. Yours must have taken a real hit somewhere.

Anyway, it is good practise to replace a prop once it starts to look funny. You don't want one of them things flying away.