Gulfstream Expands G300 and G400 Flight-Test Fleets

Gulfstream is adding aircraft to the flight-test programs for its G300 and G400 business jets. President Mark Burns said the pace of testing is accelerating, according to Aviation Week. The fourth and final planned G400 test aircraft, featuring a complete interior, joined the fleet after its first flight from Dallas Love Field, Texas. In Tel Aviv, Israel Aerospace Industries was assembling the third G300 test aircraft. Burns said the first G300 had recently flown for about 3.5 hours at approximately 48,000 feet, and the second was expected to fly soon.

A G400 test aircraft flew from Miami to the NBAA convention in 4 hours 8 minutes at an average Mach 0.89.

What has been confirmed

The details in the available fact set come from Aviation Week and carry a “likely” confidence rating; none is marked officially confirmed. The report attributes the testing update to Burns. It also says a G400 test aircraft made the Miami-to-NBAA-convention flight in 4 hours 8 minutes, averaging Mach 0.89. Aviation Week reports that the G400 first flew in August 2024 and was originally expected to begin deliveries in 2026. The G300’s first aircraft flew in December, and initial deliveries were provisionally expected in 2028. Gulfstream had not provided a certification date for either aircraft at the time of the report.

Why it matters

A growing test fleet gives manufacturers more aircraft to use across development work, while the reported Miami-to-convention flight offers a concrete performance data point for the G400 program. Certification dates and delivery timing matter to prospective operators planning future fleet additions, but Gulfstream had not provided certification dates for either jet.

FlyMarshall context

Flight testing helps a manufacturer evaluate an aircraft across a range of systems and operating conditions before certification. A test aircraft with a complete interior can also support evaluation of the cabin as part of the program. For business-aviation customers, certification and delivery timing shape when a new aircraft can enter service and how operators plan fleet changes.

What happens next

Gulfstream had not announced certification dates for the G300 or G400 in the report. The G300’s first deliveries were provisionally expected to begin in 2028; the report said the G400’s schedule had lengthened amid stricter certification requirements, including software validation. It did not provide a revised G400 delivery date.