WALTHAM, Mass. – Raytheon Technologies Corp. plans to eliminate more than 15,000 jobs this year at its corporate offices, jet engine-maker Pratt & Whitney and aviation and military equipment manufacturer Collins Aerospace amid the downturn in the airline industry, Chief Executive Officer Greg Hayes said Wednesday.The job cuts at the Waltham, Massachusetts-based company are nearly double the total it initially announced in July.Hayes, speaking during a Morgan Stanley analysts conference via webcast, said the cuts amount to administrative cost reductions of about 20% at Pratt & Whitney, based in East Hartford, Connecticut, and about 12% at Collins Aerospace, based in Charlotte, North Carolina.Pratt & Whitney has seen shop visits decline 60%.