The Airbus A320 aircraft does not have a flap setting known as “flap 4.” Instead, it offers flap settings of flap 1, flap 2, flap 3, and flap full. Flap 3 landings on the A320 are certified and commonly performed. Many pilots find flap 3 landings easier due to certain advantages they provide.
During a flap 3 landing, the aircraft’s approach speed increases by approximately 4 to 5 knots. This higher speed enhances control responsiveness, making it easier for pilots to handle the aircraft during the flare and landing phase. The increased approach angle of the aircraft with flap 3 also results in a shallower flare angle, reducing the effort required for a successful landing.
The choice between flap 3 and flap full landings is often a matter of personal preference for pilots. While the majority of landings in some airlines are performed with flaps at full, there are no specific restrictions imposed by the company regarding flap settings. Flap 3 landings are suitable even for smaller airports as the difference in landing distance between flap full and flap 3 is relatively minor, around 100 meters (330 feet).
However, there are situations where Airbus recommends or emphasizes the use of flap 3 landings. One such situation is when approaching to land in windshear conditions. In the event of windshear reported by the control tower during the approach, selecting flap 3 and increasing the approach speed by approximately 15 knots can improve the aircraft’s energy level and assist pilots in countering the effects of windshear. Additionally, flap 3 landings offer better go-around performance as per Airbus procedures, where the flaps should be retracted from flap 3 to flap 2 during a go-around, reducing drag and enhancing climb performance.
It is worth noting that not following the recommended procedures for using flap 3 in an approach with windshear can have consequences. An incident involving an American Airlines A321 in 2015 serves as an example, where the failure to follow the procedure resulted in a tail strike and a subsequent hard landing. The National Transportation Safety Board (NTSB) attributed the cause of the incident to the pilots’ failure to use flap 3 in the presence of windshear.
