The Hazards of Pulling Up Landing Gear on the Runway

Many pilots and aviation enthusiasts wonder what would happen if they were to pull up the landing gear lever on the runway itself. To put it simply, it is an extremely dangerous and costly operation often leading to significant damage or even crashes. The consequences of such actions are multifaceted and can range from severe structural damage to outright catastrophic failure.

The Mechanics of Landing Gear Retraction

Larger aircraft and some newer light retractable aircraft have a 'weight on wheels' or 'squat' switch that triggers when the aircraft is on the ground, effectively disabling the landing gear retraction sequence. This safeguard is in place to prevent the gear from retracting when the aircraft bounces slightly, lifting some weight off the wheels. While the general rule is to avoid retracting the gear on the ground, the exact consequences can vary based on the aircraft's design.

A Historical Example: No Highway in the Sky

One of the more dramatic and educational instances of this principle can be found in the classic 1955 film No Highway in the Sky. In this movie, James Stewart portrays an aeronautical engineer who suspects that a plane he is flying on is about to experience a structural failure. In a cleverly devised scene, the engineer convinces the crew to disable the aircraft by pulling up the landing gear lever while they are on the ground. This maneuver, however, did not reflect real-world physics.

According to my father, who was also an aeronautical engineer, pulling up the landing gear lever under such conditions would have no effect due to the presence of squat switches. These switches automatically disable the retraction mechanism when the weight of the plane compresses the gear struts, preventing premature gear retraction even if the aircraft bounces slightly. This insight underscores the importance of understanding both the theoretical and practical aspects of aircraft operation.

Immediate Consequences of Gear Retraction During Ground Operations

If the engine is running and the landing gear is retracted while the aircraft is on the runway, the propeller will almost invariably strike the ground. This can result in catastrophic damage to the propeller, the engine, and potentially other components of the aircraft. The cost of such damage can easily reach or exceed $50,000, with more severe incidents costing upwards of $100,000.

Additionally, retraction during ground conditions can lead to a host of other issues, such as sparks, sparks, and noise that can damage the runway or surrounding infrastructure, as well as pose a safety risk to other aircraft. In extreme cases, it can even result in a fire, adding an element of danger that no pilot would want to deal with.

Procedures and Precautions

To ensure ground operations safety, pilots and maintenance crews follow strict procedures to avoid these hazardous situations. These include:

Never retract the landing gear until the aircraft is in the air and reaching the desired altitude. Check the 'Weight on Wheels' indicator before takeoff and landing to ensure the gear is down and locked in place. Follow the manufacturer's recommendations for ground operations, which often include detailed guidelines for gear retraction and deployment. Keep the aircraft in a taxiway or parking stand when performing maintenance or during any time when the gear might be retracted for reasons other than takeoff or landing.

By adhering to these safety protocols, pilots and maintenance personnel can prevent accidents and ensure the safe operation of the aircraft.

Conclusion

The significance of properly managing aircraft landing gear cannot be overstated. Pulling up the landing gear on the runway is not only illegal and unsafe but also extremely costly. Understanding the mechanics and safety procedures associated with landing gear operation is crucial for ensuring the safety of the aircraft and its passengers. Whether for commercial flights, private jets, or experimental aircraft, maintaining proper procedures is key to preventing potential catastrophes.