If future buyers of Embraer's (NYSE:ERJ) latest "E-Jets" wind up wondering who exactly built their planes, the confusion would be understandable. Judging from a series of announcements out of aerospace supplier United Technologies (NYSE:UTX) today, it almost seems like UTC is delivering Embraer a "ready-to-assemble" plane kit!

In a trio of one-upon-the-other announcements, UTC confirmed that it will be supplying the electrical systems for Embraer's jets. And the auxiliary power units. And the engines. And the wheels and brakes, too.

Embraer's second generation of E-Jets will feature "electric power generation, emergency power generation, primary power distribution and secondary power distribution" manufactured by UTC. UTC will also supply APS2600 auxiliary power units to keep the electrical systems pumped full of ions. And, for main power, E-Jets will feature fuel-efficient PW1700G and PW1900G "PurePower" engines from UTC's Pratt & Whitney unit. Meanwhile, E-Jets will stand firmly on the ground upon UTC-built main and nose wheels, brought to a stop by UTC's proprietary DURACARB carbon braking system.

In related news, Embraer reiterated today that it has selected Honeywell (NYSE:HON) to supply its Primus Epic 2 integrated avionics system for the new planes, a contract originally announced last month.