United Technologies Corp. cut its 2015 profit forecast for the second time in just over a month, citing weak demand in the units making aerospace parts and Otis elevators. Excluding the Sikorsky helicopter business being sold to Lockheed Martin Corp., earnings this year will be $6.15 to $6.30 a share, down from $6.35 to $6.55, United Technologies said Tuesday in its second-quarter earnings report.