Facts summary and sources
Lockheed SR-71 Blackbird: speed field: Mach 3.3 (Reported flight result). First flight: 1964.
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
- NASA / National Museum of the USAF: SR-71 record β The SR-71 set a 2,193.167 mph speed record on July 28, 1976. [Straight-course class speed record; rounded to 3,530 km/h in this database.] Β· Event date: 1976-07-28 Β· Source checked for this claim: 2026-10-07
- Existing reference link Β· Source-check date not recorded
- Wikipedia reference Β· Source-check date not recorded
βοΈ Full Specifications
| Designation | SR-71A |
| Manufacturer | Lockheed Skunk Works |
| Country | πΊπΈ United States |
| First flight | 1964 |
| Service Entry | 1966 |
| Retired | 1998 |
| Crew | 2 |
| Length | 32.74 m (107.4 ft) |
| Wingspan | 16.94 m (55.6 ft) |
| Height | 5.64 m (18.5 ft) |
| Empty Weight | 30,600 kg (67,473 lb) |
| Max Takeoff Weight | 78,000 kg (171,990 lb) |
| Max Speed (Mach) | 3.3 |
| Speed evidence basis | Reported flight result |
| Max Speed | 3,530 km/h |
| Service Ceiling | 25,900 m (84,978 ft) |
| Range | 5,400 km (3,353 mi) |
| Engine | 2 Γ Pratt & Whitney J58 (JT11D-20B) hybrid turbo-ramjet |
| Thrust (each) | Dry 145 kN Β· AB 151 kN |
| Production | 32 |
π Operators
π Variants
- A-12 β Single-seat CIA reconnaissance predecessor
- YF-12 β Interceptor prototype with AIM-47 missiles
- SR-71A β Primary production reconnaissance variant
- SR-71B β Two-seat trainer with elevated rear cockpit
- SR-71C β Hybrid YF-12 + SR-71 (one built)
βοΈ Armament
Overview
The SR-71 Blackbird is a high-speed, high-altitude reconnaissance aircraft. NASA describes its design cruise condition as Mach 3.2, at altitudes up to 85,000 feet. USAF histories record no loss to enemy fire; that operational record does not mean interception is physically impossible or that every missile is slower than the aircraft. NASA flight-research overview; USAF operational history.
Explore the units with the Mach speed converter: km/h, mph and knots. Mach depends on local air temperature; a model conversion does not replace the documented flight result.
Design & Development
Designed by legendary engineer Kelly Johnson at Lockheed’s Skunk Works, the SR-71 featured revolutionary technologies: titanium airframe (85% of structure), chine-shaped fuselage for reduced radar cross-section, and unique J58 engines that functioned as turboramjets at high speed. The aircraft’s skin temperature reached over 300Β°C during cruise, causing the airframe to expand several inches.
Operational History
The SR-71 entered USAF service in the 1960s, was retired in 1990, briefly reactivated, and withdrawn from USAF service in 1998. NASA flying continued to 1999. On July 28, 1976, an SR-71 set the FAI absolute speed record for powered aeroplanes at 3,529.56 km/h. This measured course record should not be confused with a cruise specification, groundspeed anecdote or a universal Mach conversion. FAI record history; USAF retirement chronology.
Limitations & Challenges
High-speed reconnaissance required specialised fuel, thermal management, careful maintenance and mission preparation. Those demands mattered alongside the aircraftβs speed. A precise maintenance-hours or cost-per-flight-hour figure requires a dated accounting source and should not be treated as a timeless property of the design.
Sensor capability also needs to be identified by system: an optical camera and a synthetic-aperture radar do not have the same dependence on cloud cover. This page does not claim a verified ability to read a vehicle licence plate from 80,000 feet.
Fun Fact
The SR-71 leaked fuel on the ground because its titanium panels were designed with gaps to allow for thermal expansion at Mach 3+. It had to refuel shortly after takeoff.
Armament & Weapons
The SR-71 carried no offensive weapons. Its survivability involved speed, altitude and defensive equipment. The historical absence of combat losses is different from a guarantee that it could never be detected, tracked or intercepted. Equipment included:
- ASARS-1 β Advanced Synthetic Aperture Radar System
- OBC (Optical Bar Camera) β optical reconnaissance imaging; resolution depends on conditions
- ELINT sensors β electronic intelligence gathering
- DEF systems β defensive electronic countermeasures
The aircraft could survey 100,000 square miles per hour of territory.
Frequently Asked Questions
How fast is the SR-71 Blackbird?
The FAIβs documented 1976 speed record is 3,529.56 km/h. NASA gives Mach 3.2 as a design cruise condition. These describe different measurements; this page does not infer an unreported higher speed from claims about classified performance.
Why did the SR-71 leak fuel on the ground?
The SR-71’s titanium skin panels had gaps to allow thermal expansion at Mach 3+, where temperatures exceeded 500Β°F (260Β°C). At rest, JP-7 fuel seeped through these gaps.
How many SR-71s were built?
32 SR-71 aircraft were built by Lockheed’s Skunk Works division.
Is the SR-71 still in service?
No. USAF service ended in 1998 following an earlier retirement and reactivation; the final SR-71 flight was in 1999. Its record of no losses to enemy action should not be restated as βnever detected or intercepted.β
References & Sources
- [1] Merlin, P.W. (2009). Design and Development of the Blackbird: Challenges and Lessons Learned. AIAA 2009-1522. DOI: 10.2514/6.2009-1522
- [2] Graham, R.H. (1996). SR-71 Revealed: The Inside Story. Zenith Press. ISBN: 978-0760301227
- NASA Armstrong β SR-71 Fact Sheet
- Lockheed Martin β SR-71 Blackbird History
- Wikipedia β SR-71 Blackbird
Related Aircraft
Correction Scope
This update clarifies the documented speed record and retirement timeline, and removes absolute survivability and unsupported photographic-resolution, cost and maintenance claims. Other historical material is retained.