Alternator belt for R22
feel free to contact us ms@robinsonhelicopters.org

 

firetrucks
Member Since : 2009
Posts(4)
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Alternator belt for R22

10-01-2014 02:09:12

Just threw my 12 year old alt belt.  Now waiting to see how long the spare is going to last.
Any bets?????

Will a generic 3VX375 from the auto parts store be an acceptable replacement?

Replies

rotormatic
Member Since : 2010
Posts(42)
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10-02-2014 04:49:46
Will a generic 3VX375 from the auto parts store be an acceptable replacement?

No. See attached Advisory Circular

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/B3F169856B0370418625780E0055F874?OpenDocument&Highlight=replacement parts
firetrucks
Member Since : 2009
Posts(4)
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10-04-2014 12:57:54
Thanks, that answers my question.  Pay triple retail to Robinson.
rotormatic
Member Since : 2010
Posts(42)
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10-05-2014 02:03:41
NTSB Identification: LAX07LA274.

Accident occurred Friday, September 14, 2007 in El Monte, CA
Probable Cause Approval Date: 01/31/2008
Aircraft: Robinson R22 Beta, registration: N877HF
Injuries: 2 Uninjured.


While in cruise flight about 1,700 feet agl, the flight instructor heard a loud "bang" from the back of the helicopter. The alternator warning light illuminated, and he initiated the alternator emergency procedure. He noticed the engine's rpm was fluctuating with the main rotor rpm indicating high and the engine rpm low. He entered an autorotation and landed on uneven terrain; the main rotor struck the tail boom, and the helicopter rolled over onto its left side. The helicopter was examined by a Safety Board investigator. The two main drive V-belts were located in the drive compartment with one positioned on the drive pulleys in the middle slot (between the normal operating positions for the forward and aft belts), and the other was located completely off of the drive pulleys. Both belts exhibited damage on the inside including scratch marks, material and color transfers, and gouges consistent with damage by a rubber based foreign object. Rubber and color transfer in a transverse orientation inconsistent with the drive belts was noted on the upper and lower pulleys. The alternator belt was missing and not recovered. The clutch assembly was located in the up position with the actuator fully extended, and the safety stop activated. The oil cooler sustained damage to the outer fins. Rubber transfer was located on the oil cooler, starter, oil lines, and exhaust tube on a plane with the alternator belt's rotation. The alternator belt is located directly below the lower main drive pulley. No other preimpact anomalies with either the airframe or engine were discovered. As a result of this investigation Robinson is changing the specification for the alternator drive belt.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

a failure of the main rotor drive system V-belts due to damage sustained when the alternator drive belt failed and pieces of that belt got between the main drive belts and their associated pulleys. A contributing factor was the uneven terrain encountered in the forced landing.
MVH-DOM
Member Since : 2013
Posts(63)
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10-05-2014 09:20:08
My advice regarding an R22 alternator belt:  When you pull the fan to perform the bottom fan shaft bearing lube at 300 hrs or 800 hrs (depending on which bearing you have) change out the alternator belt at the same time, even if it looks good.  I change the belts on our fleet at the 800 hr bearing lube interval and have never had a broken belt yet.
SkidGear
Member Since : 2009
Posts(11)
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10-11-2014 12:10:06