Facts summary and sources
Boeing X-51A Waverider: speed field: Mach 5.1 (Reported flight result). First flight: 2010.
This is a secondary compilation. A source-check date applies only to the listed claim, not to the whole page or its translation. A page update is not a source check.
Sources and check records
- US Air Force: X-51A final flight β The final X-51A test flight reached Mach 5.1. This is a test result, not a production-aircraft service speed. [Reported flight result] Β· Event date: 2013-05-01 Β· Source checked for this claim: 2026-09-28
- Wikipedia reference Β· Source-check date not recorded
βοΈ Full Specifications
| Designation | X-51A |
| Manufacturer | Boeing (airframe), Pratt & Whitney Rocketdyne (engine) |
| Country | πΊπΈ United States |
| First flight | 2010 |
| Max Speed (Mach) | 5.1 |
| Speed evidence basis | Reported flight result |
| Engine | 1Γ Pratt & Whitney Rocketdyne SJY61 scramjet |
| Production | 4 |
Overview
The Boeing X-51A Waverider was an uncrewed experimental aircraft built to test a hydrocarbon-fueled scramjet. Its final flight on May 1, 2013 reached a peak of Mach 5.1. The program brought together the U.S. Air Force, DARPA, Boeing, Pratt & Whitney Rocketdyne and NASA. Four test vehicles flew between 2010 and 2013. [1] [3]
Design & Development
The nearly wingless cruiser used its shock wave to generate lift, giving Waverider its name. A B-52H carried the test stack to altitude; a solid rocket booster then accelerated it before the cruiser separated and started its scramjet. The complete stack was about 25 feet (7.62 m) long, including the booster and interstage. The cruiser itself was about 14 feet (4.27 m) long. These dimensions describe different parts of the test system. [3]
Pratt & Whitney Rocketdyne’s SJY61 engine burned JP-7 hydrocarbon fuel. The fuel also helped cool the engine before combustion. Unlike a turbojet, a scramjet has no rotating compressor or turbine: forward motion compresses the incoming air, and combustion takes place in supersonic airflow. This is why the X-51A needed a booster instead of taking off under scramjet power. [6]
Flight-Test History
The first flight was on May 26, 2010 and demonstrated scramjet propulsion. The second flight in June 2011 ended after a combustion problem; a control-fin failure prevented the third flight in August 2012 from completing its test. These trials led to the final flight in May 2013. [4] [2]
On the final test, the B-52H released the vehicle near 50,000 feet. Its booster accelerated it to about Mach 4.8 in 26 seconds; after separation, the scramjet accelerated the cruiser to a peak of Mach 5.1 near 60,000 feet. The vehicle was not designed for recovery and ended its flight in the Pacific Ocean. [1]
Understanding the 2013 Result
- Peak speed: Mach 5.1 β the reported maximum, not a claim that the entire powered flight stayed at this speed.
- Scramjet-powered flight: 210 seconds β three and a half minutes.
- Telemetry collected: 370 seconds β includes other phases of the flight, not just scramjet operation.
These figures follow the Edwards Air Force Base report of May 7, 2013. The earlier May 3 release also mentions a 240-second fuel supply; that figure should not be substituted for the later report’s explicit powered-flight duration. [1] [2]
Mach is a ratio to the local speed of sound, which changes with atmospheric temperature. This page therefore reports the measured Mach result without assigning it an unconditional km/h or mph equivalent. Multiplying Mach 5.1 by the sea-level speed of sound would not reproduce the speed at the test altitude. See the Mach-number guide and converter with its stated conditions. [5]
Armament
The X-51A was an unarmed research demonstrator. The test program examined propulsion, thermal protection, and airframe-engine integration for future hypersonic research; it was not an operational weapons system. [3]
Video
Frequently Asked Questions
How fast was the X-51A Waverider?
It reached a reported peak of Mach 5.1 on May 1, 2013. Mach-to-km/h or mph conversion requires the local atmospheric conditions; a fixed sea-level conversion is not the flight result.
Did it fly at Mach 5.1 for 210 seconds?
The reported 210 seconds describes scramjet-powered flight. Mach 5.1 was the peak speed reached during the mission.
How many X-51As were built?
Four purpose-built test vehicles were flown between 2010 and 2013. They were not designed for recovery.
Is the X-51A in service?
No. It was a flight-test demonstrator, and the fourth and final vehicle flew in 2013.
References & Sources
- U.S. Air Force β X-51A Waverider achieves breakthrough in final flight (May 3, 2013).
- Edwards AFB β Edwards flight testers essential to X-51A Waverider success (May 7, 2013).
- U.S. Air Force β X-51A Waverider fact sheet.
- Edwards AFB β Modified X-51A Waverider ready for next hypersonic test (March 16, 2011).
- NASA Glenn β Mach Number.
- Edwards AFB β X-51A conducts flight test (May 2010).
Further reading: Wikipedia β Boeing X-51 Waverider; Boeing β Phantom Works.