Gulfstream Aerospace is boosting the range potential of its G650 flagship with the launch of an ER extended-range version. At an EBACE press conference on May 19, Gulfstream president Larry Flynn said that the G650’s already lengthy range figure of 7,000 nm will grow to 7,500 nm at Mach 0.85, which will make it the longest-range business jet when it receives certification. Alternatively, the ER version can reach out a further 400 nm beyond the baseline G650 to fly 6,400 nm at Mach0.90.

Following Cessna’s recapturing of “world’s fastest bizjet” from Savannah’s flagship by barely a handful of knots with its upgraded Citation X, Gulfstream at least wears the crown for the longest legs and has the segment all to itself for a few more years until Global 7000/8000 deliveries begin.

Such performance opens up yet more attractive city-pairings. Gulfstream has already flown a demonstrator of the G650ER, and in one flight it covered the 7,494-nm ground distance from Hong Kong to New York in 14 hours 7 minutes, flying at Mach 0.865. The demonstrator also flew nonstop from Los Angeles to Melbourne, and with the G650ER northern Australia will be attainable nonstop for the first time from westernEurope.

Increased range can also be traded for extra speed and payload. Compared to the G650, the ER can cover a 7,000-nm sector in 30 fewer minutes by using its extra fuel capacity to fly faster. Over the same distance the G650ER can carry a 4,000-pound payload, considerably more than is possible with the G650. Maximum operating speed is Mach 0.925. The only real performance penalty for the G650ER is an increase in balanced field length at maximum weight, up 500 feet to around 6,360 feet.

Surprisingly little modification is needed to turn a G650 into a G650ER. In the original design of the aircraft sufficient space was left in the wings to add tankage for 4,000 pounds more fuel, without having to resort to auxiliary tanks in the fuselage. Despite maximum ramp weight rising from 100,000 to 104,000 pounds, Gulfstream had already built in adequate structural margins in the G650 to handle the ER’s weight increase. The engines remain the same Rolls-Royce BR725 turbofans, but the fuel quantity measuring and flight management systems have to be tweaked through software to cater for the extra tankage and performancechanges.

Gulfstream expects to receive FAA certification for the G650ER later this year, in time for deliveries to begin in next year’s first quarter. EASA approval is slated to follow in 2016. As well as new-build aircraft, the ER configuration is available as a retrofit for original G650s. Downtime for the work to be performed is less than a week.