During an incident at the Ninoy Aquino International Airport where a Philippine Airlines Boeing 777-300ER had to abort take-off, a journalist asked why the pilots didn’t proceed with the take-off. The best answer would be that the plane had not reached take-off speed, making it still safe to perform a high-energy rejected take-off (RTO). But some of you might wonder what speeds planes take-off at. Well, they all differ depending on the aircraft type, aircraft weight, present weather conditions, environmental conditions, and runway length.
For example, a Boeing 777-300ER has a take-off speed of approximately 196 mph, while an Airbus A330-300 has a take-off speed of approximately 184 mph. A Cessna 172 has a take-off speed of approximately 63 mph, while an F/A-18E has a take-off speed of approximately 138 mph.
So again, it depends on the design of the aircraft, weight, environmental conditions, and sometimes, length of the runway.
However, in order to answer why pilots sometimes have to abort a takeoff when an incident occurs instead of proceeding, I would like to explain the concepts of decision speed (V1), rotation speed (VR), and takeoff safety speed (V2).
Knowing the take-off speeds – V1, VR, and V2 – is important for pilots to have a smooth and safe take-off. These speeds help pilots make important decisions during the take-off phase. Once you understand these speeds, you’ll have a solid grasp on what goes through a pilot’s mind during take-off.
V1 Speed: Decision Speed
V1 is the decision speed. It is the speed by which the pilot must decide whether to continue the take-off or abort. If an incident occurs before reaching V1, such as an engine failure or another critical malfunction, the pilot can safely abort the take-off by applying maximum braking and bringing the aircraft to a stop. However, if the incident happens after reaching V1, the pilot must continue with the take-off, as there may not be enough runway left to stop the plane safely.
VR Speed: Rotation Speed
VR, or rotation speed, is the point at which the pilot initiates the aircraft’s nose-up attitude to lift off the runway. This speed is crucial as it ensures that the aircraft achieves the necessary lift to become airborne. VR is typically slightly higher than V1 and must be reached to ensure a smooth and controlled take-off. Proper rotation at VR helps to avoid tail strikes and ensures that the aircraft has adequate speed to climb.
V2 Speed: Take-off Safety Speed
V2 is the take-off safety speed. This speed provides a safe margin above the stall speed, allowing the aircraft to continue climbing even with one engine inoperative. V2 ensures that the aircraft has enough speed to maintain a positive rate of climb and clear obstacles. Achieving and maintaining V2 is important for ensuring the aircraft’s performance and safety during the initial climb phase.
Handling Incidents Before and After V1
Before V1
If an incident such as an engine failure, bird strike, or other critical malfunction occurs before reaching V1, the pilot will abort the take-off. This involves reducing the throttle to idle, applying maximum braking, deploying spoilers, and using reverse thrust if available. The goal is to bring the aircraft to a stop on the remaining runway.
After V1
Once the plane reaches V1, the take-off must proceed, even if an incident occurs. The pilot will continue to accelerate to VR and rotate the aircraft. After liftoff, the pilot will follow procedures to handle the emergency, such as retracting the landing gear and climbing at V2. The aircraft will then return to the airport or divert to an alternate, depending on the situation.
Training on take-off speeds and associated procedures is a critical part of a pilot’s education. Pilots must be thoroughly familiar with V1, VR, and V2 speeds for each aircraft type they operate. Simulator training provides pilots with the opportunity to practice handling various take-off scenarios, ensuring they can respond effectively to both routine and emergency situations.
To sum up, the speed required for a plane to take off varies depending on factors such as the type of aircraft, its weight, environmental conditions, and even runway length. In the event of an incident during take-off, the pilot’s decision on whether to abort or continue the take-off will depend on the decision speed. If a pilot decides to abort a take-off beyond the decision speed, there is a high risk that the plane may overshoot the runway and cause more damage.
First love never dies. I fell in love with airplanes and aviation when I was a kid. My dream was to become a pilot, but destiny led me to another path: to be an aviation digital media content creator and a small business owner. My passion for aviation inspires me to bring you quality content through my website and social accounts. Aviation is indeed in my blood and blog!
