At a June 14 press conference Xeriant and XTI Aircraft confirmed plans for a 50:50 joint venture to pursue type certification for the hybrid-electric TriFan 600 VTOL aircraft.
A two-thirds scale model of the hybrid-electric TriFan 600 aircraft made a first flight in the first week of May 2019. This was 10 months later than had originally been projected in XTI Aircraft's timeline for the program. At the time, the company said it aims to achieve type certification by the end of 2023.
In June 2019, XTI claimed to have received 81 "pre-orders" from prospective operators in North America and Australia, with a combined value of around $500 million (implying a unit price of $6.5 million). This included an order from Australia-based Heliflite, with which XTI now has an exclusive partnership in Australasia, Oceania, and Indonesia. It also included an order from Brazil-based operator Icon Aviation
On July 23, 2019, XTI selected GE Aviation's Catalyst turboprop engine to power the TriFan 600. XTI Aircraft did not say when a full-scale prototype powered by this engine will be ready to join the flight test program, and the Catalyst is due to complete its own certification process in 2020. The aircraft uses XTI's patented ducted-fan technology, with one fan on each wing and another in the rear of the fuselage. The wing-mounted fans turn forward when the aircraft transitions from vertical to horizontal flight and at that stage the rear fan is covered.
In September 2019, XTI received a Japanese patent covering its TriFan 600 design. In the same month, it signed a draft joint venture agreement with an undisclosed company in Guizhou province, China, covering possible assembly and support for the aircraft.
On October 2, 2019, XTI announced that it has moved its 65 percent-scale proof-of-concept prototype to an approved test site in northern Utah, where the next phase of flight testing is due to begin. As of that date, the prototype had made 21 flights, testing controlled takeoffs, hover and landing. The company reported that it has fully installed, tested, and validated the aircraft's electric motors, battery system, ducts, propellers, flight controls, electrical systems, and instrumentation.
The TriFan 600 is mainly intended for longer-range flights of up to 1,400 miles. XTI believes it could fill several applications, including corporate transportation and emergency medical service.
On November 11, 2020, XTI announced a new partnership with propulsion specialist VerdeGo Aero, which will provide hybrid propulsion system combining a diesel engine, electric generator, and battery pack to power a new eVTOL model called the TriFan 200. This will be smaller than the TriFan 600 and intended for autonomous, cargo-carrying applications. XTI is using the 65 percent-scale proof-of concept prototype as the baseline design for the new model.
The company has not said when it aims to achieve type certification and service entry for the TriFan 200, or how work on this aircraft may impact the development timeline for the TriFan 600. As of March 2020, CEO Robert LaBelle indicated that subject to further investment being secured through an ongoing Series B funding round, his team aimed to have a full-scale TriFan 600 prototype ready to begin flight testing during 2021.
By November 2020, XTI was reporting an order backlog of 97 units for the TriFan 600, with customers understood to include Canadian operator Helijet. The company assessed the combined value of this backlog to be $630 million, suggesting a unit price for the aircraft of $6.5 million.
By mid-April 2021, the backlog in orders had increased to 116 units, which the company said represented $750 million in gross revenues upon delivery. The company was due to close its crowd-funding campaign on April 30. On April 12, it announced the appointment of James Kromberg as chief pilot, signaling an intention to step up development and test work for the TriFan aircraft.