Gulfstream Aerospace expects to win type certificates for two new business jet types – the G500 and G600 – and putting both into service in 2018. It’s never done two at a time before.

So close are the aircraft to certification that Gulfstream has given them time off to make a star appearance here at ABACE.

The immense effort to produce the business jet industry’s leading, most technologically advanced aircraft began with their launch four years ago. The huge effort to develop and certifiy two types at the same time has involved no fewer than 10 flight test aircraft—five of each—and thousands of hours in flight test.

Both have cabins that are wider and taller than those of the G450 and G550, and high-speed cruise for both is faster: .90 Mach, which the company says will be the new normal for the segment.

Both types are fitted with Gulfstream-designed and manufactured wings – a first – and Pratt & Whitey Canada’s PW800-series engines, marking the first time U.S.-designed Gulfstreams have flown on other than Rolls-Royce power. The pair have advanced, touch-screen flight decks including electrically back-driven “active inceptor” sidesticks that move together as if mechanically linked – no other civil aircraft are so equipped.

The aircraft will also be better than originally promised. At program launch, range goals at a cruise speed of .85 Mach were 5,000 nautical miles for G500 and 6,200 nm for G600, and at .90 M were 3,800 nm and 4,800 nm respectively. After years of flight testing, the company now says the G500 will fly 5,200 nm at .85 M and 4,400 nm at .90 M, while the G600 will travel 6,500 nm at .85 M and 5,100 nm at .90 M.

The G500 will replace the G450 in Gulfstream’s lineup, and while the G550 hasn’t been terminated, almost everyone will buy the G500/600 instead.

The G450 and 550 are immensely popular in Asia-Pacific, with 66 G450s and 98 G550s in the region, according to Hong Kong consultants Asia Sky Group. While many of these will likely be replaced by the G500/600 over time, Gulfstream will not comment on orders for the new aircraft.

Gulfstream also has 46 of its flagship G650 and 24 G650ERs in the region, proving the popularity of large-cabin, high-speed business jets.

The company is also showing other Gulfstreams here including the G650ER and G550, as well as the super-midsized G280.