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Old 15th Jun 2004, 18:11
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safetypee
 
Join Date: Dec 2002
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xjav8or, it’s unfortunate that your management may not have considered the design principles behind the Avro REDU thrust setting. REDU is a ‘fixed’ flex thrust setting which is quickly selected, gives an appropriate engine life saving whilst maintaining crew confidence. The thrust rating was specifically chosen to avoid the oddities of N1 increasing with Climb selection as you have seen. I recall that the details for the REDU setting were placed in the normal checklist to encourage its use as the normal operation.

I doubt that there is any ‘real’ additional engine life benefit by using Max Flex; the EGT is slightly lower than for REDU, but the engine still has a hot cycle. There is no fuel benefit, as you still require the same amount of energy to get the aircraft in the air. Do not forget that you (or management) will get a different story from the engine manufacturer. Ultimately, it is the operator’s choice, but it should be a balance between extreme economics, safety, and a happy, confident operating crew.

When management read the small print in the AFM for winter wet/contaminated runway operations, they may get a nasty shock. Also, if you take the RJ to Aspen etc, don’t trade economics against a legal, but less than sensible and safe operation.
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