Guys, posted this question in Tech Log forum but didn't get a response, maybe someone here can help ?
I fly for a private organization that has recently purchased an aircraft fitted with a couple of P&W PT6A-67D engines and I would like to know what other operaters are using as a standard power setting. You see my boss thinks that 'long range cruise" is the best (feels as if you could get out and run faster) but will allow us to use "intermediate cruise power" (slightly faster) but calls the "high speed cruise" (from the AFM) "emergency power" (his words!!). Now considering that at ICP the turbines are idling along at 92 to 93 percent and even at HSC they are only running at 96 to 97 (which, if I remember back to my BGT theory,is where the designers anticipated they would spend most of their working days and where they are most efficient) and that Max. Continuous is 104%, would we be doing anything to shorten the life of the engine or increase overhaul costs (bosses justification for the LRC policy) by running them at the higher power setting? There is another consideration here and that is operting costs.If, for example, this beast costs, say, $2000 an hour to operate and we make it go faster then at the end of the month (and we do about 100 hors per month) we could well save about 10% in flight time, or $20,000. Okay, so there will be an increase in fuel burn but the extra fuel, even at todays prices , is cheaper than flight time.
Anyone out there have a comment on this one??
