Why Aircraft Must Reduce Speed Before Landing

The air travel industry operates on strict safety protocols, one of which is the requirement for aircraft to reduce speed before landing. This is a critical procedure to ensure a safe and smooth touchdown, as landing at full cruising altitude and velocity would be disastrous. Understanding the reasons behind this requirement, as well as the potential consequences, will help clarify why this step is so crucial.

The Importance of Speed Reduction

Before touching the runway, an aircraft must drastically reduce its speed. If an aircraft attempts to land at its normal cruising speed, several immediate and severe issues arise. Firstly, the landing gear is not designed to support such a high impact. An impact at a speed of over 500 nautical miles per hour (knots) would result in the destruction of the aircraft, leading to a catastrophic crash and, unfortunately, the death of all on board.

The Physics Behind Landing

The objective of a safe landing is to stall the aircraft right when it is about to make contact with the runway, ensuring the plane is just a few feet above it. This requires a significant speed reduction. If the aircraft is not aligned properly with the runway, it could veer off course and land dangerously, or worse, crash into obstacles.

Risk of High-Speed Landing

Commercial planes maintain cruising altitudes of over 5 miles above ground. These altitudes are much higher than most airports, primarily because there are no airports built at such heights. The highest point on Earth—Mount Everest—reaches around 29,000 feet, which is not high enough to provide a safe altitude for landing. Even if a runway were to exist at such an altitude, landing at high speed would pose numerous problems:

Heat Generation: At such high speeds, the aircraft would generate excessive heat from atmospheric friction, which could lead to structural damages. Fuselages could warp, wings could crack, and other critical components could fail.

Brake Failure: The brakes of a commercial jet cannot handle the thermal stress of such a high-speed landing. Using the brakes at these speeds would cause them to overheat and catch fire, leading to a total destruction of the aircraft.

Insufficient Runway Length: The runway would be far too short to stop a plane moving at 500 nautical miles per hour. This short runway length would result in a spectacular failure, with the plane either veering off the runway or causing a catastrophic crash.

Comparison with Smaller Aircraft

While larger commercial jets are at significant risk of catastrophic failure if they attempt a high-speed landing, smaller aircraft like the Cessna 150 might still have a chance. However, even in this case, care must be taken to avoid exceeding the flap-limited speed, which is the maximum speed at which the flaps can be extended safely. Commercial jets, on the other hand, have a specific minimum runway landing distance, which varies based on several factors. Landing at a speed of 500 knots or more would be phenomenally dangerous, leading to exploded tires and overheated brakes, ensuring total destruction before the aircraft can leave the runway.

Conclusion

In summary, the necessity of reducing speed before landing is a fundamental aspect of aviation safety. Proper speed management is crucial to ensure a safe touchdown and prevent the catastrophic failure of an aircraft. This practice is not just a regulatory requirement but a critical safety measure that must be followed to prevent accidents, fatalities, and extensive damage. An ounce of common sense validates this requirement, making such questions on platforms like Quora seem somewhat redundant. Understanding these principles is essential for passengers, pilots, and aviation professionals alike to ensure safer air travel.