XB-1, Boom’s supersonic demonstrator aircraft, continues to progress toward Mach 1. Beginning with XB-1’s historic first flight on March 22, 2024, the aircraft is advancing through its flight test program to confirm its performance and handling qualities, with approximately 10 subsonic flights planned before reaching supersonic speeds.
XB-1 provides the foundation for the design and development of Overture, Boom’s supersonic airliner. XB-1 leverages state-of-the-art technologies to enable efficient supersonic flight including digitally-optimized aerodynamics, carbon fiber composites, advanced supersonic engine intakes, and an augmented reality vision system for takeoff and landing visibility.
Here, we’ll be sharing updates throughout the XB-1 flight test program to keep you up to speed with the aircraft’s progress toward supersonic flight.
Nov 5, 2024 – XB-1 Flight Seven
Oct 25, 2024 – XB-1 Flight Six
Oct 7, 2024 – XB-1 Flight Five
Sep 21, 2024 – XB-1 Flight Four
Sep 13, 2024 – XB-1 Flight Three
Nov 5, 2024
XB-1 Flight Seven
Max altitude: 23,015 ft
Speed: Mach 0.82 (499 knots true airspeed)
Flight time: approximately 55 minutes
Pilot: Chief Test Pilot Tristan “Geppetto” Brandenburg
Key test points:
- New top speed of Mach 0.82 (499 knots true airspeed)
- Expanded altitude envelope to 23,015 ft
- Cockpit pressurization test at maximum pressure differential
- FES testing at Mach 0.7, 0.75, and 0.8 test points
On November 5, 2024, XB-1 successfully completed its seventh of ten planned subsonic test flights as the team continues to make steady progress toward supersonic flight. Flight seven focused on flutter envelope expansion and cockpit pressure testing in order to ensure safe performance and handling qualities as XB-1 approaches supersonic speeds and higher altitudes.
This flight marks a new top speed for XB-1 at Mach 0.82, or 499 knots true airspeed. The XB-1 team performed tests of the flutter excitation system (FES) at higher speeds than previous flights – hitting Mach 0.7, 0.75, and 0.8 test points to ensure that the aircraft handles predictably up to transonic speeds.
XB-1 reached a new top altitude of 23,015 feet, allowing the team to perform a final cockpit pressurization test at maximum pressure differential, ensuring that it is safe to proceed up to 30,000 feet – the altitude XB-1 will fly when it reaches supersonic speeds. This is a human-piloted aircraft, so just like the pressurized cabin in every airliner, XB-1 maintains a pressurized environment for the pilot due to the physiological issues that occur at high altitude.
XB-1 continues to perform at progressively faster speeds and higher altitudes, expanding the flight envelope gradually to prepare the aircraft and team for breaking the sound barrier at Mach 1.
Oct 25, 2024
XB-1 Flight Six
Max altitude: 20,000 ft
Speed: Mach 0.67
Flight time: approximately 38 minutes 30 seconds
Pilot: Chief Test Pilot Tristan “Geppetto” Brandenburg
Key test points:
- Demonstrated successful flutter test point at increased airspeed at 0.65 Mach
- Demonstrated successful FES operation in flight
- Expanded altitude envelope to 20,000 ft
On October 25, 2024, XB-1 successfully completed its sixth test flight and continues to make progress in expanding the envelope for supersonic flight.
Flight six primarily targeted flutter and handling qualities testing at a higher altitude than previous flights. The FES, or flutter excitation system, is crucial in testing new aircraft to ensure there are no undesirable interactions between the airflow around the vehicle and the structure of the aircraft. Flutter is a phenomenon where the energy from the airflow can interact with the airframe vibration modes and cause structural failure. Modern aircraft design uses tools and predictions to develop aircraft that should not be susceptible to flutter, which we verify with testing. In this flight, XB-1 made significant progress towards validating a fully functional FES system.
Unfortunately, we did experience a degradation in GPS signal strength which impacted our ability to accomplish more in this flight. The team is currently troubleshooting this issue and as soon as the source of interference is identified and corrected, we will be on to Flight 7.
Boom’s Flight Test Program Approach
Oct 7, 2024
XB-1 Flight Five
Max altitude: 17,800 ft
Speed: 0.69 (428 knots, TAS)
Flight time: approximately 50 minutes
Pilot: Chief Test Pilot Tristan “Geppetto” Brandenburg
Key test points:
- New top speed of Mach 0.69 (428 knots, TAS) achieved
- Landing gear up right after takeoff
- Continued testing of the flutter excitation system (FES) at Mach 0.6
- Handling quality, flutter, and pacer checks at progressively higher speeds
On October 7, 2024, XB-1 took to the skies for its fifth flight from the Mojave Air & Space Port, climbing to 17,800 feet in the R-2515 Airspace. Flown by Chief Test Pilot Tristan “Geppetto” Brandenburg, XB-1’s fifth successful flight marks the halfway point of the 10 planned subsonic test flights before breaking the sound barrier. This is the fastest, highest, and longest flight so far as XB-1 progresses through the flight test program on the way to supersonic flight later this year.
The flutter excitation system (FES) was repaired and reinstalled for this flight in order to continue data collection at the Mach 0.6 flutter point. The FES is a critical system during this phase of test flights, and will be used extensively to clear the flight envelope up to transonic speeds. Flying and handling quality checks were performed at progressively higher speeds, including pacer checks and flutter tests as XB-1 reached a new top speed at Mach 0.69 (or 428 knots, true airspeed). The landing gear was retracted immediately following takeoff, which will become standard procedure during future test flights.
What Happens Between Flights?
Sep 21, 2024
XB-1 Flight Four
Max altitude: 16,150 ft
Speed: 0.617 (382 knots, TAS)
Flight time: approximately 48 minutes
Pilot: Chief Test Pilot Tristan “Geppetto” Brandenburg
Key test points:
- New top speed of Mach 0.617 achieved
- First use of the flutter excitation system (FES) in flight
- Handling quality checks between 225 and 300 knots
- Applied elevated g-forces of 2.78g in preparation for supersonic flight
- Landing gear extended and retracted at 225 knots (max safe speed)
Just eight days after its third test flight, XB-1 successfully completed its fourth – and fastest – test flight on September 21, 2024. During this flight, XB-1 reached the highest speeds so far at Mach 0.617, or 382 knots true airspeed – more than halfway to breaking the sound barrier at Mach 1.
This flight marks the first use of the flutter excitation system (FES) in flight. The FES is a vibration device that we can turn on in order to hit structural vibration modes deliberately before we would encounter them naturally in flight.
In addition to checking basic handling qualities of the aircraft at various speeds between 225 and 300 knots, the team took XB-1 up to 2.78g (or g-force), using a flight test technique called a wind up turn to put elevated g-forces on an aircraft. This is the highest we intend to see during XB-1’s flight test program. When we get to supersonic flight, XB-1 will have to clear a turn at 2g to line up for the supersonic run – the team is testing the aircraft with an extra margin to increase safety.
The landing gear was retracted at a max speed of 225 knots, completing this portion of system testing. During future test flights, the team will retract the landing gear immediately after takeoff.
The flight reached a maximum altitude of 16,150 feet, with a total flight time of 48 minutes. XB-1 was flown by Boom Chief Test Pilot, Tristan “Geppetto” Brandenburg, who flew the second and third flights of XB-1 and will also pilot the aircraft’s first supersonic flight.
Sep 13, 2024
XB-1 Flight Three
Max altitude: 15,000 ft
Speed: 289 knots, TAS
Flight time: approximately 32 minutes
Pilot: Chief Test Pilot Tristan “Geppetto” Brandenburg
Key test points:
- Achieved maximum pitch and yaw attitudes expected in flight
- Environmental control system (ECS) checks and tuning
- Landing gear extended and retracted at 215 knots
- Continued testing of the stability augmentation system
On September 13, 2024, XB-1 flew for the third time, and Chief Test Pilot Tristan “Geppetto” Brandenburg was at the controls.
During this flight, the team continued to test key systems and performance as they systematically expand the flight envelope. The pilot, Geppetto, took XB-1 to the maximum pitch and yaw attitudes that we expect to see in flight. This testing was done at a safe, higher altitude to ensure there were no unexpected handling qualities. We do this kind of testing so that the first time it happens, it is not in a critical phase of flight.
The team also checked the performance of the environmental control system (ECS), which controls the temperature and pressurization of the cockpit. This test is to ensure that the ECS is functioning as designed before XB-1 goes to higher altitudes, where it is colder and the pressure is lower. The landing gear was extended and retracted at higher speeds than previous flights (215 knots), marking the second of three steps working up to the maximum safe speed for raising and lowering the gear, which is 225 knots. Additionally, the team continued testing of the stability augmentation system.
Read more on XB-1’s third flight here.
Aug 26, 2024
XB-1 Flight Two
Max altitude: 10,400ft
Speed: 270 knots, TAS
Flight time: approximately 15 minutes
Pilot: Chief Test Pilot Tristan “Geppetto” Brandenburg’s first flight in XB-1
Key test points:
- Landing gear retracted and extended in-flight for the first time
- Digital stability augmentation system demonstrated in-flight
- Tufting applied to the right wing in order to verify aerodynamic characteristics
In August, XB-1 successfully completed its second flight at the Mojave Air & Space Port in Mojave, California with Chief Test Pilot Tristan “Geppetto” Brandenburg at the controls for the first time.
The landing gear was retracted and extended in flight for the first time, which is typical of second test flights. The XB-1 team also assessed aircraft handling qualities, and demonstrated a new stability augmentation system, or roll damper. This roll damper was implemented to improve handling qualities based on learnings from first flight.
Read more on XB-1’s second flight here.
Mar 22, 2024
XB-1 Successfully Completes First Flight
Max altitude: 7,120ft
Speed: 264 knots, TAS
Flight time: 12 minutes
Pilot: Bill “Doc” Shoemaker
Key test points:
- Initial assessment of the aircraft’s handling qualities
- Airspeed checks with the T-38 chase aircraft
- Assessing the aircraft’s stability in the landing attitude
On March 22, 2024, XB-1, the world’s first independently developed supersonic jet, took flight for the first time at the Mojave Air & Space Port in Mojave, California.
Piloted by Test Pilot Bill “Doc” Shoemaker, XB-1 safely and successfully achieved an altitude of 7,120 feet and speeds up to 238 knots (273 mph). While XB-1 was in the air, the team performed an initial assessment of the aircraft’s handling qualities, including airspeed checks with the T-38 chase aircraft, and assessing the aircraft’s stability in the landing attitude (at a high angle of attack).
“XB-1 took flight in the same hallowed airspace where the Bell X-1 first broke the sound barrier in 1947,” said Blake Scholl, founder and CEO of Boom Supersonic. “I’ve been looking forward to this flight since founding Boom in 2014, and it marks the most significant milestone yet on our path to bring supersonic travel to passengers worldwide.”
Two decades after Concorde’s retirement, the historic first flight of XB-1 marked the return of a civil supersonic aircraft to the skies and paves the way for the revival of mainstream supersonic travel onboard Overture, Boom’s sustainable supersonic airliner.
Learn more about XB-1’s first flight here.
XB-1 is Boom’s technology demonstrator aircraft and the world’s first independently developed supersonic jet. The aircraft first took flight in Mojave, CA in March 2024. Read more about XB-1 here.