✈️ Aircraft Specifications
| Designation | X-43A |
| Manufacturer | Boeing / NASA |
| Country of Origin | United States |
| First Flight | 2004 |
| Length | 3.66 m (12 ft) |
| Max Speed (Mach) | 9.6 |
| Max Speed (km/h) | 11,265 km/h |
| Service Ceiling | 33,528 m (110,005 ft) |
| Engine | Supersonic combustion ramjet (scramjet) |
| Status | Retired |
Overview
The X-43A holds the record for the fastest aircraft ever—reaching Mach 9.6 (11,265 km/h) on November 16, 2004. This unmanned experimental hypersonic aircraft demonstrated the viability of air-breathing scramjet propulsion, a technology that could revolutionize both military systems and access to space.
Design & Development
Unlike rocket-powered vehicles, the X-43A used a supersonic combustion ramjet (scramjet) that breathes atmospheric air, compressing it through its forward body shape rather than mechanical compressors. Hydrogen fuel was injected into supersonic airflow inside the combustion chamber. The 3.7-meter-long vehicle was boosted to scramjet ignition speed by a modified Pegasus rocket launched from a B-52.
Operational History
Three X-43A vehicles were built. The first test in 2001 failed when the Pegasus booster went off course. The second flight on March 27, 2004 achieved Mach 6.8. The third and final flight on November 16, 2004 reached Mach 9.6—nearly 10 times the speed of sound—setting the current world speed record for air-breathing aircraft.
Armament
The X-43A carried no weapons. It was a pure research vehicle for scramjet propulsion technology. Each of the three vehicles was expended during its single test flight. The technology feeds into hypersonic weapons programs like ARRW and HACM.
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Frequently Asked Questions
How fast is the X-43A?
The X-43A reached Mach 9.6 (7,310 mph) on November 16, 2004 — the fastest aircraft ever flown and a world record for air-breathing engines.
How was the X-43A launched?
It was mounted on a Pegasus rocket booster, carried by a B-52 Stratofortress. The booster accelerated it to scramjet ignition speed.
How many X-43A vehicles were built?
3 X-43A vehicles were built for NASA’s Hyper-X program. Two flew successfully.
Is the X-43A still in service?
No. It was an unmanned experimental vehicle for scramjet research.