Zunum Aero (Seattle Tacoma International), a hybrid-electric regional aircraft startup, has launched a new bid to raise funds, having been unsuccessful in finding the level of investment it needs to continue developing its nine- to twelve-passenger ZA10.

The company has been forced to halt operations, lay off "nearly all" of its 70 employees, and abandon its headquarters in Seattle and its facilities in Illinois after failing to close a USD50 million Series B funding round as planned last year, Forbes has reported.

In May 2018, Zunum said its hybrid aircraft, the first of a planned family that would fly at up to 340mph (550kmh) and complete short-haul passenger journeys of up to 1,000 miles (1,600 kilometres), would make its maiden flight in 2019, emitting up to 80% fewer pollutants than conventionally powered jets.

The plan was to build an airframe propelled by two large ducted fans driven by electric motors together with a gas turbine to recharge the batteries. The startup won millions in funding from Boeing and JetBlue Airways, which sank a combined USD6.2 million into the company in Series A funding in April 2017, according to documents obtained by the Puget Sound Business Journal.

But when it ran short of cash late last year, operations came to a halt, former employees told Forbes, adding that at the facilities in Elgin, Illinois, where Zunum's electric motor was being created, creditors had seized the equipment, and the locks had been changed. Two unpaid wage complaints against Zunum have been lodged at the Illinois Department of Labor.

“Like startups often have to do, we have been navigating a challenging period. However, our team remains committed to a future with electric flight everywhere,” CEO Ashish Kumar said in a statement.

In April 2018, Zunum obtained bridge loans from JetBlue Technology Ventures and Boeing HorizonX in the expectation that it would pursue further investment. The founders have told former employees that a new bid to raise funds will succeed and that operations will restart, but so far this has not materialised.