Boeing 737-300 vs. Boeing 737-600

The Boeing 737-300, launched in the early 1980s, is a seminal model in the 737 family, known for ushering in the era of modern narrow-body jetliners. As the first of the 737 Classic series, it was developed to meet the growing demand for more efficient and higher-capacity short to medium-haul aircraft. Compared to the Original 737 models, the -300 featured new wings, a redesigned tailfin, and improvements inside the cabin. Fast forward a bit, the 737-300 was eventually replaced by the 737-700 of the Next Generation series.

The 737-300 stretches 109.6 feet (33.4 meters) from nose to tail, with a wingspan of 94.5 feet (28.8 meters). This aircraft was Boeing's answer to the need for a larger capacity in the single-aisle market, accommodating 128 passengers in a typical two-class layout. Its increased length over its predecessor, the 737-200, allowed for additional seating, making it a more economical choice for airlines.

Equipped with two CFM International CFM56-3B1 engines, the 737-300 produces a total thrust of 44,000 lbf (196.0 kN). This enhancement in power, combined with a fuel capacity of 5,310 US gallons (20,100 liters), extended the aircraft's range to 2,376 nautical miles (4,400 kilometers). The 737-300's cruise speed of 495 mph (796 km/h) made it a swift and efficient option for airlines, reducing flight times on popular domestic and regional routes.

The 737-300 marked a shift in the commercial aviation landscape, competing with models like the McDonnell Douglas MD-80. Its launch was pivotal for Boeing, demonstrating the company's ability to innovate and adapt to market shifts. The 737-300's popularity was driven by its improved efficiency, greater capacity, and enhanced performance, meeting the needs of airlines expanding their short-haul operations.

Major carriers such as Southwest Airlines and United Airlines incorporated the Boeing 737-300 into their fleets, capitalizing on its operational advantages. The American carriers purchased a majority of the -300, with 299 units between the two airlines. The aircraft's role in these fleets was significant, as it enabled airlines to offer more frequent services and open new routes, particularly in the domestic and regional markets.

Launched in 1998, the Boeing 737-600 is the smallest aircraft in the 737 Next Generation (NG) series. It succeeded the 737-500, and was a significant evolution in Boeing's narrow-body offerings. It featured many upgraded features from the previous 737s, including aerodynamics, engines, and avionics. As the smallest NG variant, the 737-600 was designed for efficiency and adaptability, catering to airlines requiring a compact jet for short to medium-haul routes.

This aircraft extends 102.4 feet (31.2 meters) in length with a wingspan of 112.6 feet (34.3 meters). The 737-600, with a typical seating capacity for 123 passengers, offers an ideal balance between passenger comfort and efficiency, making it a fitting choice for airlines serving routes with moderate passenger demand. Equipped with two CFM International CFM56-7B20 engines, the 737-600 has a total thrust of 45,400 lbf (202.0 kN). This engine power, coupled with a fuel capacity of 6,868 US gallons (26,000 liters), gives the -600 a range of 3,051 nautical miles (5,650 kilometers). The 737-600 has a cruise speed of 528 mph (850 km/h) enabling airlines to maintain efficient and swift operations, particularly beneficial for regional network connections.

In the late 1990s and early 2000s, the Boeing 737-600 competed with aircraft such as the Airbus A318 and Bombardier CRJ series, offering airlines a modern alternative in the narrow-body market. Airlines including Scandinavian Airlines (SAS), Westjet, and Air Algerie operated the Boeing 737-600. Ultimately, the -600 variant was not a popular model of the 737 due to its economics. The -700, only slightly heavier, had a much greater payload. Additionally, the larger market was moving more towards higher capacity narrow-bodies with lower unit costs and greater revenue opportunities.