Why Do Large Jets Hang or Level Out Briefly Just Before Touchdown?

Just before touching down on the runway, large commercial jets often perform a brief hang or level-out maneuver. This maneuver, commonly referred to as the 'flare,' is a crucial part of the landing procedure designed to optimize the aircraft's preparation for touchdown. Understanding the purpose and technique behind this maneuver is vital for both pilots and aviation enthusiasts alike.

The Purpose of the Flare Maneuver

The primary objective of the flare during a commercial airliner landing is to reduce the descent rate and the aircraft's speed. This is achieved through a controlled pitch-up of the aircraft just above the runway to decelerate without substantially affecting the aircraft's altitude. The flare serves three critical functions:

Slow the aircraft from the final approach speed to touchdown speed.

Reduce the rate of descent to a level acceptable for touchdown.

Change the aircraft's attitude from the position suitable for final approach to one suitable for touchdown.

Without an adequate flare, the resulting touchdown is likely to be abrupt and firm, leading to an "incomplete flare" critique. Conversely, if the flare is performed excessively or the pilot begins it with too much energy, the aircraft may experience a "balloon" or "float" phenomenon, where the descent is too smooth and the touchdown is delayed.

Technique for Large Jets Landing

Large jets, such as the Boeing 777 or Airbus A330, require precise execution of the flare maneuver. This is because the pilot has to rely on instruments rather than visual cues, unlike smaller aircraft like the Boeing 737 or smaller regional jets. The flare is typically initiated when the aircraft is at an approximate 30 feet above the runway, which is referred to as the 'flare altitude' or 'radar altitude.' The pilot will call out 'flare altitude' to alert the co-pilot and then pitch the aircraft up, hustle the thrust levers to idle, and deploy various aerodynamic devices like speed brakes and reverse thrust to manage the aircraft's descent rate.

Full Landing Procedure

The entire landing procedure for a commercial jet involves several steps, including the approach phase and the flare maneuver. Here is a brief overview of the process:

Approach the runway with the Precision Approach Path Indicator (PAPI) lights aligned with the desired approach path.

Once above the threshold of the runway, decelerate by leveling out the aircraft and reducing engine thrust.

Deploy speed brakes and reverse thrust to further control the descent rate.

Initiate the flare maneuver by gently pitching the aircraft up at an appropriate altitude (around 30 feet above the runway).

Settle the aircraft onto the runway with controlled pitch and thrust adjustments.

Conclusion

Understanding the nuances of the flare maneuver is crucial for safe and efficient landings in commercial aviation. Pilots must execute the flare precisely to ensure a smooth touchdown, preventing abrupt and firm landings or excessive float. The technique is finely tuned to achieve an optimal balance in the aircraft's speed, descent rate, and final approach attitude. By mastering this maneuver, pilots can ensure a safe landing, providing comfort and reassurance to both the flight crew and the cabin passengers.