PPRuNe Forums - View Single Post - Bristow S76 Ditched in Nigeria today Feb 3 2016
Old 10th Feb 2016, 07:56
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Mars
 
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We have probably done this to death but any discussion about the ability for a gearbox to 'run dry' is nearly always a conditional statement. For example, Giuseppe Gasparini, head of transmission systems design and development at AgustaWestland makes this observation:

I prefer to say “Loss of Lubrication,” or LoL, and not “run dry” or “run without oil”; we are demonstrating the capability of the gearbox to operate and transmit torque after the loss of most of its original lubricant when the oil is suddenly lost, but some residual lubricant is still inside the gearbox. This means the MGB can continue to run for 30 minutes without loss of drive or any other catastrophic failure after the pilot notes a major lubrication system failure, normally identified as a low pressure warning, and immediately reduces power to the minimum required to maintain forward flight and lands as soon as possible.
Notwithstanding this, there have been real advances in the material used, and the finishing, for contacting surfaces within the gearbox.

(As with previous posters, this is not a comment on the S76 accident.)

Mars
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