MD Helicopters (MDHI) has delayed certification for the 2.5t MD6XX civil helicopter by at least two years to focus the small manufacturer's resources on delivering a surge of orders from military customers, says chief executive Lynn Tilton.

The delay comes only a year after Tilton unveiled a mock-up of the MD6XX and promised to complete certification by the end of 2018.

That timeline became unachievable as MDHI copes with new orders by at least three foreign militaries for the armed version of the MD530 light-single. The Mesa, Arizona-based manufacturer is expected to deliver 30 helicopters by the end of this year, including the first five by the end of May, Tilton says.

Additional orders by Kenya and Lebanon have added to the backlog for the MD530, but require additional certifications that have consumed the engineering department, Tilton says.

"We just didn't have the resources" to make progress on the MD6XX, she says. "We're not stopping it. We’re excited about it, but in the end I just couldn't do it all."

The MD6XX concept unveiled last year represents the company's most ambitious new product launch for the civil helicopter market since Tilton acquired MDHI in 2005.

The design resembles the shape of the MD600N, but replaces the NOTAR anti-torque system with a four-bladed rotor. The MD6XX is also loaded with new technologies, including S411 main rotor blades, an extended composite tail boom, a Genesys Aerosystems glass cockpit, boosted flight controls and a three-axis digital autopilot.

Asked to suggest a new timeline for certification, Tilton thought briefly and, with some hesitation, replied, "2020".

"We’re still working on the design. I have a design team working on it," she says. "But I can’t work on [certificating] it until I get through all of these deliveries."