Greenvalley285 Posted October 9, 2016 Report Share Posted October 9, 2016 We are responsible for maintaining a fleet of Jet Ranger II and III helicopters. For last 3-4 Months, we are facing a recurring fault. That is after 20-30 minutes of flying, Low Oil Press and rising Oil Temp, is observed on Xmsn (Transmission) Oil Instrument. This has been observed on 2-3 helos. we have done every thing to trouble shoot (faulty indication system, Adjust PRV, Replace Xmsn also)..... But of no use.I share here it also, we are using Aeroshell Turbine Oil 560 (HTS grade). 3-4 Months back, our supplier of Lubs, told us that now same oil is sold in new packing (Oil can colour changed from yellow to Blue), but according to him specifications are same. My question is, If it is Oil (HTS grade) causing any trouble. I donot agree, with some arguments, that, it is the oil which is causing trouble. We have another oil available in supply, that is TURBONYCOIL 600. It is available in Std Grade (Not HTS Grade). What are your opinion, if i switch to this brand of Oil. OffCourse, we will adhere to instructions as specified in relevant Maintenance Manuals, regarding draining/ flushing of Oil. Your opinion is wellcome... Quote Link to comment Share on other sites More sharing options...
Eric Hunt Posted October 11, 2016 Report Share Posted October 11, 2016 Are you overfilling the reservoir? A known occurrence is when the oil is too full, it froths up, doesn't flow properly through the cooler (gets hot) and the bubbles confuse the pressure sensor (low pressure). I have had it happen when a new pilot filled it past the sight line in the window. Quote Link to comment Share on other sites More sharing options...
iChris Posted October 20, 2016 Report Share Posted October 20, 2016 (edited) We are responsible for maintaining a fleet of Jet Ranger II and III helicopters. For last 3-4 Months, we are facing a recurring fault. That is after 20-30 minutes of flying, Low Oil Press and rising Oil Temp, is observed on Xmsn (Transmission) Oil Instrument. This has been observed on 2-3 helos. we have done every thing to trouble shoot (faulty indication system, Adjust PRV, Replace Xmsn also)..... Be a little more specific, transmission oil pressure low and temperature high, meaning low/high but within normal range or outside normal range? I once had a Bell 206B III on a seismic contract that held just within range (see photo) any time OAT was above 90ºF: Maintenance found a partially blocked air duct just passed the oil cooler blower and clogged passages at the oil cooler on the transmission. After those two issues were corrected, maintenance followed up with the transmission oil pressure adjustment. So we went from 35 PSI up to 45 PSI on pressure and from 105ºC down to 85ºC on temperature. Transmission oil pressures and temperature depend a lot on the environment you’re operating in and the type of loads the aircraft is moving. I don’t see the oils you’re using, Aeroshell 560 and 555, as an issue since both are per the Bell manual. Below are items you should look into. As stated in Eric Hunt’s post above, transmission oil level too high. Evidence of foaming causing low oil fluctuation. Transmission oil level low. Obstructed air duct into transmission oil cooler air passages. Cooler internal air passages clogged. Clogged or damaged oil jets Pressure relief value out of adjustment, leaking or faulty. Oil pump faulty. Packings on Jet faulty. Oil filter faulty. Transmission filled with improper lubricating oil. Is your transmission oil pressure light flickering on the ground at flight idle on hot days? See link below:TRANSMISSION OIL PUMP 206-040-184-101, Bell Technical Bullet Edited October 21, 2016 by iChris Quote Link to comment Share on other sites More sharing options...
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