Textron Aviation has started producing Cessna Citation Longitude business jets in Plant IV at its east Wichita campus – the first time a Cessna has been manufactured alongside Beechcraft airplanes.

The company has four production Longitudes in various stages of assembly, including some for delivery to customers.

It also flew a third Longitude on Friday that will be used in its flight-testing program. A spokeswoman said Monday the company will manufacture two more Longitudes for flight testing.

“The speed at which our team is achieving these milestones is an important indication to our customers of the maturity of the aircraft’s systems and the proficiency of our processes,” Brad Thress, Textron Aviation senior vice president of engineering, said in a news release.

Assembly on the first four production Longtiudes were begun at Plant IV, 101 N. Greenwich, following installation of new tooling, Textron Aviation spokeswoman Sarah Estes said.

The line occupies a spot in the plant previously occupied by the Hawker 4000, production of which ended in 2013. Textron Inc. acquired Beechcraft in 2014 and merged it with Cessna to create Textron Aviation.

Textron Aviation’s third Longitude will test the model’s Garmin G5000 avionics and systems development. The aircraft also will collect flight simulator data.

The company first announced the Longitude – Cessna’s largest Citation yet – at the National Business Aviation Association Convention in 2012 and brought a nonflying prototype of the $23.9 million jet to the NBAA Convention in 2015.

Last year, its first flight-test Longitude was on static display at the NBAA Convention in Orlando, Fla.

Textron Aviation expects to receive Federal Aviation Administration type certification for the jet later this year, followed immediately by customer deliveries.