Why does 777 300er have no winglets

Somerville installed the devices on his early biplane and monoplane designs. To the naked eye, the difference between sharklets and winglets is in name only.

Their purpose is to cut down on fuel— between 3. Whether they're called sharklets or winglets, those wing tips are no small matter. As of September , the had been involved in 31 aviation accidents and incidents , including 8 hull losses 5 during flight and 3 on the ground with fatalities, and 3 hijackings.

So why don't all airplanes have winglets? The airflow around winglets is complicated, so designing them is tricky. It's easier to improve an airplane's lift-to-drag ratio by simply making the wing longer , though this can lead to other problems, such as fitting into gates. Because of their lightweight, incredible strength, and smooth finish , carbon fiber composites are an ideal material from which to build many parts of an aircraft.

The use of carbon fiber for aircraft bodies allows them to be more fuel-efficient, more aerodynamic, and to be built with fewer and lighter parts. A: Airplane wings are often curved on the top and flat on the bottom, which makes them look teardrop shaped! This is because of Bernoulli's Principle.

Bernoulli's Principle states that faster moving air has lower air pressure and slower moving air has higher air pressure. Due to the angle at which the wing is fixed to the aircraft fuselage, higher air pressure is experienced on the lower surface of the wing than on the upper surface.

This creates a pressure difference between the top and bottom sections of the wing, which generates lift upward movement of the aircraft. The winglets, which curve out and up from the plane's wing tips, improve an airplane's performance and allow it to fly more than km farther than a without winglets. Winglets also offer excellent environmental benefits, including reduced fuel use, takeoff and landing noise, and in-flight engine emissions. A wing tip or wingtip is the part of the wing that is most distant from the fuselage of a fixed-wing aircraft.

Because the wing tip shape influences the size and drag of the wingtip vortices, tip design has produced a diversity of shapes, including: Squared-off.

Depending on the airplane, its cargo, the airline's routes, and other factors, blended winglets can: Lower operating costs by reducing block fuel burn by 4 to 5 percent on missions near the airplane's design range. Weight is probably the biggest disadvantage to having winglets, for obvious reasons.

In addition, the extra weight can result in the need for further reinforcement of the wing, which also adds weight. Near the wing tips, the high-pressure air under the wing rushes to the lower-pressure areas on top, which results in the creation of vortices.

The vortices flow in a three-dimensional manner over the wings. They not only pull air up and over the wing, but they also pull air back. That third component is induced drag. With the advent of winglets, the aircraft is able to weaken the strength of wingtip vortices and, more important, cut down on induced drag along the whole wing.

But in many instances, airplane makers simply don't have the option of making the wings longer. For example, narrow-body airliners such as the Boeing and often operate from gates at airports designed for short- to medium-range domestic flights.

Since these flights usually require smaller aircraft, they have less room apportioned to them. As a result, wingspan is effectively limited by the size of the parking space the plane is allotted at the gate. So instead of the adding wingspan by making the wings longer, Boeing adds wingspan by going vertical with winglets.

In some instances winglets aren't necessary, because there are no constraints on space. For example, Boeing's hot-selling wide-body airliner does not have winglets. According to Gregg, that's because the operates from international terminals designed for larger jumbo jets. Looking to the future, the upcoming Boeing X series will boast a variety of technological improvements over its predecessors.

One of these futuristic aspects will be folding wingtips. Boeing is set to be the first manufacturer to deploy such technology on a commercial airliner. However, interestingly, its European competitor Airbus also patented a similar system in However, by folding the wingtips inwards on the ground, this is reduced to Much like previous triple-seven variants, this means the X is just narrow enough to be classified under aerodrome code E. As such, operators will be able to fly the X to a greater variety of airports than if it did not have this feature.

Furthermore, as it shares the same category as older s, this will allow for greater flexibility in terms of swapping between variants. What do you make of the Boeing family as a whole? Have you ever flown on one, or maybe even multiple triple-seven variants? Let us know your thoughts and experiences in the comments!