Gulfstream G400: First Flight with a Finished Cabin and a Record from Miami

Gulfstream has reached two milestones with the G400 at once: the first flight of a test aircraft carrying a complete passenger cabin, and a new city-pair speed record flown on a blend of sustainable aviation fuel (SAF). The manufacturer announced both on 19 October 2026 in Savannah, Georgia, with the 2026 NBAA Business Aviation Convention and Exhibition (NBAA-BACE) in Las Vegas as the backdrop.

A real cabin in the air

Flight test aircraft usually serve the engineers first, so a fully furnished example marks a change of focus. Gulfstream says its outfitted G400 is dedicated to evaluating the cabin systems at altitude and to checking how functional and comfortable the interior is in flight. On its first sortie, from Dallas Love Field, it stayed airborne for 2 hours and 46 minutes and climbed to 48,000 ft.

The interior is laid out for 11 passengers across two and a half living areas. From here on, the questions a buyer asks can be answered in the air rather than in a showroom: how quiet the cabin is at cruise, how the seats and the galley work, how light and temperature behave on a long sector. Our article on cabin altitude and jet lag explains why such details shape how passengers feel on arrival.

Gulfstream claims "the largest cabin in its class" for the G400. Mark Burns, president of Gulfstream, says the company will "continue to refine the interior fit and finish" as it prepares the aircraft for entry into service.

Miami to Las Vegas in a little over four hours

The second milestone came on the way to the show. One of the three experimental G400 test aircraft flew from Miami to Las Vegas in 4 hours and 8 minutes, at an average speed of Mach 0.89, and set a new record for the city pair. The flight was made on a blend of SAF. Gulfstream presents it as further evidence of the combination of speed, range and efficiency it sees in the aircraft.

A city-pair record is flown between two named airports, which makes it more tangible than a brochure line, although wind and weight on the day always play a part. How published performance figures should be read is the subject of our spec sheet guide; what a SAF blend does and does not achieve is covered in our article on emissions.

Thin air, deep cold

Beyond the two headline flights, the programme has completed a broad range of missions. Gulfstream names high-altitude testing in Telluride, Colorado, and cold-weather testing in Iqaluit, Canada, among other validation work. Campaigns of this kind check how engines and systems behave at the edges of the envelope, where thin air or a cold-soaked airframe asks more of both.

Burns calls the certification programme rigorous and says the aircraft "continues to perform exceptionally well". Gulfstream has not yet named a date for certification or for the first customer delivery.

Where the G400 fits

Gulfstream describes the G400 as category-leading. Its current family runs from the super-midsize G300 through the G400, G500 and G600 to the ultralarge-cabin G700 and the ultralong-range G800. At NBAA-BACE the experimental G400 and a cabin mock-up are on show next to the G700, G800, G500 and G600 and a mock-up of the all-new G300. For a sense of scale at the top of the range, see our G700 profile.

The company, whose first purpose-built business aircraft, the Gulfstream I, flew in 1958, counts more than 3,500 aircraft in service worldwide. For prospective G400 customers, the next figures worth waiting for are the certified ones: range, field length and cabin dimensions as they will appear on the final specification.

Questions

When did the outfitted Gulfstream G400 fly for the first time?

Gulfstream announced the first flight on 19 October 2026. The aircraft took off from Dallas Love Field, stayed airborne for 2 hours and 46 minutes and reached 48,000 ft.

How many passengers does the outfitted G400 seat?

The outfitted test aircraft is configured for 11 passengers across two and a half living areas. It is used to evaluate the cabin systems and comfort in flight.

What speed record did the Gulfstream G400 set?

One of three experimental G400 test aircraft flew from Miami to Las Vegas in 4 hours and 8 minutes at an average of Mach 0.89, a new city-pair record. It was flown on a blend of sustainable aviation fuel.

Is the Gulfstream G400 certified yet?

Not yet. Gulfstream says the programme is making continued progress toward certification, and has not yet named a date for entry into service.

Figures checked 20 October 2026. Prices are indicative and never a quote. Seen something out of date? Tell the editors.