Self-Pushback: When and How Aircraft Can Move Without Tugs

Introduction

Not all aircraft require specialized ground handling equipment such as tugs to move on the ground. Many modern commercial jetliners, turboprop aircraft, and even some business and military aircraft are capable of moving through a process known as self-pushback. This article explores which aircraft can perform self-pushback, the mechanics behind it, and the reasoning behind why it is not a common practice.

Which Aircraft Can Perform Self-Pushback?

Turbofan and Turboprop Aircraft

Most modern commercial jetliners and turboprop aircraft can perform a self-pushback using their engines. These aircraft typically have the necessary technology to reverse their thrust. Examples include:

Boeing 737 Airbus A320 Bombardier Q400

Business Jets

Many business jets can also perform self-pushback. These aircraft often have redundant engine power to ensure safety and maneuverability:

Gulfstream G650 Cessna Citation series

Military Aircraft

Some military aircraft, designed for short takeoff and landing (STOL) capabilities or those with high thrust-to-weight ratios, can also perform self-pushback:

Lockheed C-130 Hercules Boeing KC-135 Stratotanker

Mechanics of Self-Pushback

Self-pushback relies on the aircraft's ability to reverse thrust. Turbofan engines, which are commonly found in commercial jetliners, can generate reverse thrust by changing the direction of the jet exhaust. Turboprop engines, which are found in some commercial and military aircraft, can use variable pitch propellers to create reverse thrust. This reverse thrust can provide the necessary momentum for the aircraft to move backwards.

Problems with Reverse Thrust

Although reverse thrust can be effective, it is rarely used for ground operations to move aircraft. This is due to several factors:

Noise: Reverse thrust produces a significant amount of noise, which can be disruptive and unsafe near airport operations. Efficiency: Using reverse thrust for ground movements is less fuel-efficient compared to having a tug handle the task. Safety: Reverse thrust can be dangerous if misused, leading to potential damage to engines and other aircraft parts.

Common Practice and Historical Context

Even in the past, some aircraft were occasionally moved under their own power. A notable example is the DC-4 and its variants, such as the MD-80 series and Boeing 727. Pilots have reported instances of these aircraft performing self-pushback during the late 1980s and early 1990s. While it was not a common practice, it was occasionally done at major airports such as DFW, ORD, and LGA. However, this practice was eventually stopped due to safety concerns and a few minor wingtip collisions.

The Federal Aviation Administration (FAA) addressed these issues by issuing guidelines and restrictions to ensure safer ground operations. This shift in policy highlights the importance of balancing the convenience of self-pushback with the safety and efficiency requirements of airport operations.

Conclusion

Aircraft capable of self-pushback represent a significant advancement in ground handling. However, the practice has largely fallen out of favor due to safety, noise, and efficiency concerns. Ground handling tugs still play a crucial role, ensuring precise and safe movement of aircraft on the ground. Understanding the potential of self-pushback can provide valuable insights into the future of aircraft mobility and ground operations.