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Old 21st Jul 2007, 18:21
  #11 (permalink)  
ericferret
 
Join Date: Dec 2005
Location: England
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The S76A had fans driven by the engines, one mounted below each engine air intake in the plenum.

The S 76A+ and the C have fans driven by the engines mounted on the back of the each engine module 5.

A gas turbine with no cooling will overtemp it's oil system in no time flat.
To wit one Allison in a BO 105 with the return and vent lines cross connected in effect bypassing the cooler. Cooking time to very well done about 5 minutes!!!!!!! Don't ask why the pilot wasn't watching the oil temp guage.

Even if you uprated the 155 rotorbrake the engines would overtemp as there is only one fan (main tranmission driven) for all 3 oil coolers. No transmission rotation no cooling. In point of fact the 155 fan is on the end of the shaft that the brake is mounted on!!!!!!!! Couple this with the fact that the gearbox has not been designed for the high loading generated by a braked rotating engine.

Last edited by ericferret; 21st Jul 2007 at 18:37.
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