What A320 Sharklets Could Mean For An Airline Like IndiGo

Boeing 747-400 Winglet; Source: Boeing

Despite the advances in other areas, Airbus has lagged behind when it comes to large wingtip devices. The conventional and all too familiar wingtip fences that we see on the Airbus A300s, A310s, A320s and the A380s have done their job, but a scope for improvement always existed. Airbus A330s and the A340s broke from the norm by employing conventional winglets, similar to the ones seen on a Boeing 747-400.

On the 30th of November 2011, this wingtip complacency was relegated to a page in history. Airbus retrofitted the first ever A320 to be produced (MSN 001) with “Sharklets,” what Airbus calls their winglets. With this maiden flight, Airbus is ready to give to the world a much awaited confirmation and assurance of a winglet that will finally make its way to its production aircraft.

An Airbus A320 with Winglets, which Airbus calls "Sharklets"; Source: Airbus

First, let me give a brief explanation of how winglets work. Vortices form at the tips of wings as a result of the pressure difference that exists between the upper and lower surfaces of the wings. These vortices induce a drag which reduces the wing’s aerodynamic efficiency. Winglets are small , nearly vertical aerodynamic surfaces which are designed to be mounted at the tips of aircraft wings. A properly designed winglet impedes these vortices, shifting them instead further up to the tip of the winglet, resulting in much weaker vortices. As a result, the induced drag is significantly reduced, improving the lift to drag ratio of the new compound wing structure.

An increased lift to drag ratio implies lesser engine thrust requirement for a desired amount of lift, which directly relates to fuel savings. Like other winglets, these Sharklets bring with them a bundle of promises, the biggest of which is a 3.5% fuel saving over 3000NM-long flying sectors, and around 1% fuel saving over 500NM long sectors, in comparison to A320s flying with the conventional wingtip fences. These promises are fairly realistic. It cannot be underestimated how much a 3.5% fuel saving matters to airlines.

An example of an airline which will be affected by the new winglets is Indigo Airlines. Indigo Airlines is a low cost carrier based in India. Indigo operates only 1 fleet type, the A320, on a mix of medium haul international and short haul domestic routes. Almost a year back, Indigo made worldwide aviation headlines when it was one of the first airlines to agree to order 150 A320neo, which had been recently launched. It is continuing to expand rapidly in the Indian market.

The fuel savings caused by fitting Indigo’s A320s with sharklets are staggeringly large. Based on the flight schedule, Indigo can comfortably deploy one A320 on the Bangalore-Mumbai-Singapore-Mumbai-Bangalore pattern every day. Fuel cost at Bangalore and Mumbai have been approximated to be the same.

With this pattern, the same A320 operating with Sharklets can save about US$400,000per annum on fuel related costs.

According to John Leahy of Airbus, the price for the winglet will be similar to the forward fit, of around US$950,000. The retrofit kit may add to the cost, but the addition will not be substantial. Sharklets attached to an A320 flying the above pattern can pay back for itself in 2.5 years. Six A320s in Indigo’s fleet (INA-INF) are 5 years old. If Indigo plans to get rid of aircraft around 5 years old, a potential US$ 1M is saved by the airline, per aircraft.

But these are not the only savings. Either the revenue payload can be increased by 500kgs, or the range can be extended by 100NM at the original payload. The increased lift to drag ratio of the wing will result in higher available takeoff weights, notably from obstacle-limited runways, and where runway performance is not limiting, operators could profit from a reduction in average takeoff thrust (with consequent savings in engine maintenance costs by around 2%). The Sharklets lend the aircraft a better takeoff performance and rate-of-climb, higher optimum altitude, higher residual aircraft value, and greater safety margins in the event of an engine failure. All these mean money for the operator.

When you think about the fact that these cost savings will be available to every single operator of the A320 worldwide, thousands of aircraft will be reducing fuel burn and costs. This is a major improvement for airlines’ profit margins, the fares that customers pay, the environment with regards to emissions, and more. It will be interesting to watch for other improvements announced by aircraft manufacturers in the future.