Even if it
was detrimental to engine life, and you refrained from using hotel mode very often - the engine inspection/overhaul schedule would still be determined by cycles & flighthours (methinks
). If there had been any evidence whatsoever that excessive H-mode had increased wear & stress on the engine once the nominal inspection interval came up, I'm fairly confident PW/ATR would have been quick to ammend the FCOM.
In other words, same intervals = same maintenance cost per flighthour/cycle + no excessive wear = same component cost per inspection. This - in my limited vocabulary - sounds as though there is absolutely no cost savings to be had by NOT using hotel mode, whereas yield may drop when passengers refuse to fly with somebody offering a too hot or cold cabin for comfort when boarding. Of course you could use ground conditioners or heathers, but unless your airline has its own equipment, it is normally very expensive to rent from the airport (if available at all).
If company not happy with H-mode, should have considered the Dash 8 instead, since it comes with an APU
Brgds,
Empty