Pratt & Whitney Rocketdyne SJY61
Pratt & Whitney Rocketdyne SJY61 is a hydrocarbon-fueled supersonic-combustion ramjet (scramjet) identified by the U.S. Air Force as the X-51A Waverider cruiser powerplant. The Air Force describes the engine as JP-7-fueled/cooled in the 500-1,000 pound-class and reports that the X-51A reached scramjet-powered hypersonic flight. A separate Air Force ground-test report identifies the SJX61-2 designation used in flight-clearance testing.
Identity
- Aliases
- SJY61SJY61 scramjet
- Domains
- aviation
- Identity Level
- model
- Kind
- scramjet
- Name
- Pratt & Whitney Rocketdyne SJY61
- Status
- historical
Details
- Description
- Pratt & Whitney Rocketdyne SJY61 is a hydrocarbon-fueled supersonic-combustion ramjet (scramjet) identified by the U.S. Air Force as the X-51A Waverider cruiser powerplant. The Air Force describes the engine as JP-7-fueled/cooled in the 500-1,000 pound-class and reports that the X-51A reached scramjet-powered hypersonic flight. A separate Air Force ground-test report identifies the SJX61-2 designation used in flight-clearance testing.
- Propellants
- JP-7 jet fuelatmospheric air
Links
Assets & Meta
- Creation Time
- September 8, 2026 at 08:58:46 UTC
- Updated Time
- September 8, 2026 at 09:04:05 UTC
Other
- Search Name
- Pratt & Whitney Rocketdyne SJY61 SJY61 SJY61 scramjet
- Sources
- Accessed Date
- 2026-09-08
- Note
- The Air Force identifies the X-51A powerplant as a JP-7-fueled/cooled Pratt & Whitney Rocketdyne SJY61 supersonic-combustion ramjet and describes it in the 500-1,000 pound-class thrust range.
- Publisher
- U.S. Air Force
- Title
- X-51A Waverider
- Accessed Date
- 2026-09-08
- Note
- The Air Force Test Center identifies the Pratt & Whitney Rocketdyne-built air-breathing scramjet and states that the X-51\u0027s SJY61 engine ignited after rocket-booster acceleration and separation.
- Publisher
- Air Force Test Center
- Title
- May 26, 2010: Waverider Scramjet
- Accessed Date
- 2026-09-08
- Note
- The final-flight report documents the X-51A\u0027s hydrocarbon-fueled scramjet demonstration at Mach 5.1 and describes the program as a hypersonic technology demonstrator.
- Publisher
- U.S. Air Force
- Title
- X-51A Waverider achieves breakthrough in final flight
- Accessed Date
- 2026-09-08
- Note
- The ground-test article names SJX61-2 for flight-clearance testing.
- Publisher
- Wright-Patterson Air Force Base
- Title
- X-51A Scramjet Advances a Step Closer to Flight Clearance