3 divisions: Otis Elevator, Carrier heating & air conditioning, and Pratt & Whitney aircraft engines
My husband worked for the Otis division for 37 years.... GREAT company to work for!
In the 1980's my GF's dad was a nuclear technology expert for United Technologies. He used to go all over the world giving speeches about nuclear technology... at least until he drank himself to death.
Also Sikorsky Aircraft (helicopters including H-60 Black Hawk and H-53 Sea Stallion) and Hamilton Sundstrand (electronics and other systems for aircraft, mostly military).
United Technologies Research Center often has a defense focus.
Forgot Sikorsky Aircraft - make of Black Hawk helicopters, among other platforms.