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500 Performance Loss With Pma Blades


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Hi Guys,

 

Excuse me if this topic has come up at all already? A question for the 500 drivers out there. Recently our machine Time Xed it's MD blades so new PMA blades were fitted. The machine now seems to have a significant loss in performance since the change when flying in similiar conditions. I have also flown Machine's with PMA blades before and they just don't seem to have the same go.... Has anyone else experienced this at all ??

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Never experienced performance loss on PMA blades but be very careful in the TE inspections. I almost lost a blade and two lives with an unannouced blade crack top and bottom! It was 18 inches in from the root. Looked like a knife cut through the top and bottom skins leading edge to trailing edge!

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Guest Angry Egg Driver

We have had machines working side by side on seismic jobs.One with MD blades and the other with PMA blades.The MD blades will lift about 200 Lbs more then the PMA ones.

 

The blades on the 500 are definately the weak link.Over the past few years I have heard of a few blades that have departed in flight.Prism lost therer chief pilot to one,Ruperts Land had one come off in a 100 foot hover in the prairie's a few years back and many other close calls where the cracks were found on the ground before anyone was hurt.I have personally seen 2 cracked blades and heard of countles others.The most common place that PMA blades crack is on the bottom side of the blade near the doubler.

 

We just had a machine that had a cracked PMA blade.It was replaced with a new blade that was on the machine for less than 20 hrs and the plastic tip cap blew off the end of the the blade.The end of the blade started to bulge from what I was told.

 

Starting to have serious concerns about flying these machines anymore............ :down:

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Never experienced performance loss on PMA blades but be very careful in the TE inspections. I almost lost a blade and two lives with an unannouced blade crack top and bottom!  It was 18 inches in from the root. Looked like a knife cut through the top and bottom skins leading edge to trailing edge!

 

What's the difference between a helicopter pilot and a pizza?...A pizza can feed a family of four!!

 

T-Rex I like your joke at the bottom. Actually its no joke its the truth. Should start a topic on this if there isn't one already.

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Thanks for the response guys. Your comments about the two 500's working side by side Angry Egg sounds similiar to what we found..150-200 lb's out the door. I would be interested in how many guys out there have experienced blades cracking M/R or T/R and on what sort of machine R22, Jet box, 500 etc...,Your experience T-Rex sounds like short changing material !!!

 

I will be keeping a very close eye upstairs :blink:

 

Cheers TT

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Guest Angry Egg Driver

By cranking up the rotor rpm wouldn't you have a continuous overspeed.I can't imagine that the components would like that a whole bunch.More stress on an already weak blade.....sometimes it makes you wonder hey #### :unsure:

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...I would be interested in how many guys out there have experienced blades cracking M/R or T/R and on what sort of machine  R22,...

Not my personal experience, but brought to mind a couple of, umm, interesting ( :shock: ) reports involving cracks on R22 blades.

 

http://www.aaib.gov.uk/cms_resources/dft_a..._pdf_023934.pdf

 

http://www.aaib.gov.uk/cms_resources/Robin...DERB%208-05.pdf

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those 500 blades are so small, any difference in chord length etc, no matter how small, could be enough to reduce the performance to those levels. I'm not sure where the PMA manufactures got their drawings, or how close their tolerances are, but you just never know. One thing I'd verify is if the tabs are all at zero...if they are all at a degree or two, there's a good place to lose some performance.

 

there's one operator out there who's pilots just crank up the rotor rpm (governor adjustment) to get more performance...why doesn't every just follow suit?  :down:

Transport Canada can't bust everyone for it, and since it's not logged, that last engineer who touched it will get the blame anyway.

 

good idea to overspeed it :down: i take it your a pilot, not that i have anything against pilots, just dumb ones.

 

as for the blades painting the inboard 22" or so (whatever the bulletin says i forget) with a good quality WHITE paint such as endura helps detect the cracks, using spray paint will eventually turn into thousands of cracked paint lines that look like cracks, personally i have seen 4 blades crack 3 were MD and one PMA and all were painted white which is why they were detected early, definietly keeping a close eye on them is a must. As for the PMA blades i believe HTC is coming out with a new blade soon.

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