What is IN on Boeing 737? (Inches)

The Boeing 737 is a widely used aircraft in the aviation industry. With its long history and numerous variants, the Boeing 737 has become a staple in commercial aviation. When discussing the dimensions and measurements of this aircraft, one often comes across the term “inches.” In this article, we will explore what “inches” means in the context of the Boeing 737 and its significance in various aspects of the aircraft’s design and operation.

The Role of Inches in the Boeing 737 Design

Inches, abbreviated as IN, are used in the Boeing 737 design to denote specific measurements and dimensions. These measurements play a crucial role in different areas, including the aircraft’s structure, systems, and interior configuration.

Fuselage Dimensions

One of the key areas where inches are significant in the Boeing 737 is the fuselage dimensions. The fuselage is the central part of the aircraft, accommodating passengers, crew, and cargo. It is necessary to ensure the dimensions are accurate for the proper functioning and safety of the aircraft.

The outer diameter of the Boeing 737 fuselage is approximately 148 inches (3.76 meters) for the 737-600, 737-700, 737-800, and 737-900 models. This dimension helps in determining the size of the cabin and its overall capacity.

Moreover, the inner diameter of the fuselage is approximately 138 inches (3.51 meters) for the same variants. This measurement is crucial for configuring the interior cabin layout, including the arrangement of seats and aisles, to optimize passenger comfort and maximize space utilization.

Cabin Layout and Inches

Inches also play a significant role in determining the cabin layout of the Boeing 737. The seating arrangement, aisle width, and overall space allocation within the cabin are influenced by precise measurements in inches.

The average width of the aisles in the Boeing 737 is around 19 inches (48.3 centimeters). This dimension ensures that passengers can safely move about the cabin during various stages of the flight, including boarding, in-flight service, and deplaning.

When it comes to seat pitch, which refers to the distance between two rows of seats, the Boeing 737 offers a range of options. The standard seat pitch in economy class is typically 31 inches (78.7 centimeters), providing a reasonable amount of legroom for passengers.

However, airlines have the flexibility to configure their Boeing 737 aircraft with different seating arrangements. Some airlines opt for a denser layout, resulting in reduced seat pitch to increase overall capacity, while others prioritize passenger comfort and offer generous seat pitch.

Inches in Navigation Instruments

Inches play a vital role in the navigation and control systems of the Boeing 737. Various instruments and displays rely on precise measurements to provide accurate information to the pilots and ensure safe flight operations.

For instance, the altimeter, which indicates the altitude of the aircraft, is calibrated in feet. One foot is equivalent to 12 inches. Pilots rely on this measurement to maintain the desired altitude during flight and comply with air traffic control instructions.

Additionally, the airspeed indicator and vertical speed indicator also utilize inches in their readings. The airspeed indicator measures the aircraft’s speed relative to the surrounding air, while the vertical speed indicator assists in monitoring the rate of climb or descent, both expressed in feet per minute.

By understanding the significance of inches in these instruments, pilots can effectively monitor and control the aircraft’s performance, ensuring a safe and efficient flight.


When exploring the dimensions and measurements of the Boeing 737, the term “inches” plays a crucial role. Whether it is the fuselage dimensions, cabin layout, or navigation instruments, precise measurements in inches are essential for the design, operation, and safety of this widely used aircraft.

External Links

For further information about the Boeing 737, you can visit the official website here.

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