pavane88 Posted January 2, 2018 Share Posted January 2, 2018 Hello. C-130H mechanics! I have a question about C-130H prop' dynamic balancing. We are currently using the VXP equipment C-130H prop' balancing data collection is HSGI and 7000 in-lbs We performed a check both of which exceeded the limit(within 0.2 ips) However, reducing ips of 7000 in- lbs increases ips of HSGI Is it normal for HSGI's ips to go too high when ips is reduced to 7000 in-lbs? Can it be corrected inversely? If so, which section should IPS be based on? Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted January 4, 2018 Share Posted January 4, 2018 i havent used the balancer yet so cant answer your question directly. however, a couple years ago we got a newly overhauled prop in the test cell. Everything was fine up to NGI. As throttle was advanced and blade angle increased, the prop noise and RGB vibration increased. Above 1000° TIT the noise was like someone or something beating on your chest - unpleasant, almost painful. RGB vibration was topping at 1.4 to 1.6 mils. We went through the prop records and everything seemed to be in order. We then did a loose blade and tracking check, which also checked good. While standing a distance away from the engine looking at the prop, we thought there was an optical illusion. It seemed that the #2 and #4 blades were narrower than #1 and #3. On measuring the width at various points from the tip to +- halfway in, we found the #2 and #4 blades around 2 inches narrower than the others. These 2 blades had a couple thousand hours on and had been reworked several times, while the other 2 were new. Essentially there were 2 blades working their asses off, and 2 just along for the ride. My thoughts are the noise and vibration were being generated by the 2 working blades being at a higher than efficient angle and probably very close to stalling. Just something to think about ..... Quote Link to comment Share on other sites More sharing options...
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