In a sign that testing activity has resumed since an incident six weeks ago, Embraer’s KC-390 arrived at the company’s US base in Jacksonville, Florida on 20 November to begin a series of flight tests before certification.

The KC-390's flight test centre is based deep in Brazil's interior at the remote Gavião Peixoto complex. But Embraer will test its dual-role transport and tanker in Jacksonville, evaluating avionics systems, crosswind operations and external noise.

Embraer Defense and Security chief executive Jackson Schneider is optimistic the KC-390 will achieve certification on time by the end of this year. Embraer is scheduled to deliver the first aircraft to the Brazilian air force in 2018.

On 6 October, the first of two KC-390 prototypes, registered PT-ZNF, experienced a stall speed incident that grounded the aircraft. Embraer says the aircraft was not significantly damaged and will return to flight testing after minor repairs.

Flight tracking websites show that the aircraft which arrived in Jacksonville was the second KC-390 prototype, which is registered as PT-ZNJ.

So far, the KC-390 test fleet has accumulated 1,450 flight test hours since the first example achieved first flight nearly three years ago.

The Brazilian air force has ordered 30 KC-390s, including the two prototypes, to replace a fleet of Lockheed Martin C-130H tactical transports. The Portuguese government also has authorised the purchase of five KC-390s, with an option to buy a sixth.

Four more countries – Argentina, Chile, Colombia and the Czech Republic – have expressed interest in buying a combined 26 more.