Boeing 737-400 vs SR-71 Blackbird - Comparison

The Boeing 737 Classic are narrow-body airliners produced by Boeing Commercial Airplanes, the second generation of the original Boeing 737-100/-200. Development began in 1979 and the first variant, the 737-300, first flew in February 1984 and entered service in December of that year. The stretched 737-400 first flew in February 1988 and entered service later that year The shortest variant, the 737-500, first flew in June 1989 and entered service in 1990. It is re-engined with higher bypass ratio CFM56 turbofans for a better fuel economy and has upgraded avionics. With a 133,500–150,000 lb (60.6–68.

0 t) MTOW, it has a range of 2,060 to 2,375 nmi (3,815 to 4,398 km). At 102 ft (31 m), the -500 is similar in length to the original 737-200 and can fly 110 to 132 passengers. The 110 ft (33.4 m) long -300 can seat 126 to 149 passengers while the 120 ft (36.4 m) long -400 accommodates 147 to 168 seats. It competed with the MD-80 family, then with the Airbus A320 which prompted Boeing to update its offer with the 737 Next Generation, thus designating the -300/400/500 variants the 737 classic. In total, 1,988 aircraft were delivered until the year 2000: 1,113 -300s, 486 -400s and 389 -500s.

Source: Wikipedia

The Lockheed SR-71 "Blackbird" is a long-range, high-altitude, Mach 3+ strategic reconnaissance aircraft developed and manufactured by the American aerospace company Lockheed Corporation. It was operated by both the United States Air Force (USAF) and NASA.The SR-71 was developed as a black project from the Lockheed A-12 reconnaissance aircraft during the 1960s by Lockheed's Skunk Works division. American aerospace engineer Clarence "Kelly" Johnson was responsible for many of the aircraft's innovative concepts. The shape of the SR-71 was based on that of the A-12, which was one of the first aircraft to be designed with a reduced radar cross-section. At one point, a bomber variant of the aircraft was under consideration, before the program was focused solely on reconnaissance. Mission equipment for the reconnaissance role included signals intelligence sensors, side-looking airborne radar, and a camera; the SR-71 was both longer and heavier than the A-12, allowing it to hold more fuel as well as a two-seat cockpit. The SR-71 designation has been attributed to lobbying efforts by USAF Chief of Staff General Curtis LeMay, who preferred the SR (Strategic Reconnaissance) designation over simply RS (Reconnaissance, Strategic). The aircraft entered service in January 1966.

During aerial reconnaissance missions, the SR-71 operated at high speeds and altitudes (Mach 3.2 and 85,000 feet, 25,900 meters), allowing it to outrace or entirely avoid threats. If a surface-to-air missile launch was detected, the standard evasive action was simply to accelerate and outpace the missile. On average, each SR-71 could fly once per week due to the extended turnaround required after mission recovery. A total of 32 aircraft were built; 12 were lost in accidents with none lost to enemy action. During 1988, the USAF retired the SR-71 largely for political reasons; several were briefly reactivated during the 1990s before their second retirement in 1998. NASA was the final operator of the Blackbird, retiring their aircraft in 1999. Since its retirement, the SR-71's role has been taken up by a combination of reconnaissance satellites and unmanned aerial vehicles (UAVs); a proposed UAV successor, the SR-72, is under development by Lockheed Martin, and scheduled to fly in 2025. The SR-71 has several nicknames, including "Blackbird" and "Habu". As of 2022 the SR-71 still holds the world record it set in 1976 as the fastest air-breathing manned aircraft, previously held by the related Lockheed YF-12.

Source: Wikipedia