Boeing: What Is New On The Boeing 777X?

Boeing 777X, showing the difference between the -8X and the -9X 

 

The success of the Boeing 777 led to demand for an even more sophisticated generation of the Boeing 777: The Boeing 777X. The 'X' was launched at the Dubai Air Show 2013, gathering record breaking orders and commitments. Boeing said it was not a question whether there would be a successor of the current 777 generation, but more of a question when this new generation aircraft would be on the market.

The success of the Boeing 777X can be attributed to the highly successful Boeing 777-300ER, Boeing 777-200ER and the increased demand for aircraft in the coming decade. The Boeing 777X consists of 2 variants: the -8X and the -9X.

 

 

 

The Boeing 777-8X has range capabilities that are slightly better than that of the Boeing 777-200LR and can carry about as many passengers as the Boeing 777-300ER and should compete with the Airbus A350-1000.

The Boeing 777-9X with its advanced technologies is an airplane that has no competition at all and could function as a replacement for the Boeing 747-400.

So with the 777X, Boeing brings 1 aircraft to the market that will carry more passengers, but with similar payload numbers as the -200LR and 1 aircraft that will carry about the same amount of passengers but with increased range capability to replace the Boeing 747-400.

 

 

In order to bring an aircraft to the market with increased range capability and the ability to carry more passengers, Boeing made significant changes to the 777 design to accomplish a fuel burn per seat that is 20% lower than on the Boeing 777-300ER:

 

Engines

One of the biggest changes on the 777X is the use of GE9X engines. Compared to the GE90-115B (Boeing 777-300ER), the GE9X engines sport fewer blades, fan blades made out of a lighter composite, use of a lighter ceramic material and laminar flow nacelles made out of composites. The aforementioned changes result in a lower engine weight. Additionally, the engine operates under higher pressure-ratio conditions.

This results in the GE9X engine specific fuel consumption being 10% lower compared to the GE90-115B.

GE claims that the GE9X engines will be the quietest engines ever produced while reducing the NOx emission.

 

 

 

Wing Design

Another big change is the use of CFRP for the wings instead of aluminum alloys such as Al7055.

While Al7055 has a density of 2.86 kg per cubic decimeter, CFRP has a density of 1.7 - 1.95 kg per cubic decimeter. This means that a wing made out of CFRP instead of aluminum is 31.81% - 40.6% lighter.

Additionally, the span will increase from 64.8 m (Boeing 777-300ER) to 71.1 m, it is estimated that this will result in a wing area that is 10% larger than that of the Boeing 777-300ER (427.8 m²). This brings the wing area of the 777X to 470.58 m².

The aspect-ratio (span²/wing area) is of great importance to reduce the drag coefficient (Cd_induced), since the drag coefficient that can be attributed to the lift can be decreased by increasing the aspect-ratio of the wings.

The aspect ratio of the 777-300ER is 9.815, while the 777X has an aspect-ratio of 10.74. By increasing the aspect-ratio the lift induced drag coefficient possibly has been reduced by 11%.

 

Fuselage design and Passenger comfort

Boeing decided not to design a fuselage made out of CFRP to reduce the development costs. If Boeing would have decided to make a fuselage out of composite the operational empty weight of the Boeing 777X would have been reduced even further, enabling the plane to fly even further or carry more passengers (or a combination of both) or size down the wings and engines. But a redesign of the fuselage would be equivalent to designing a complete aircraft, making a service entry in 2020 almost unreachable.

To increase passenger comfort the Boeing 777X will have bigger windows and an interior similar to that of the Boeing 787. Additionally, the cabin width will be increased by approximately 12 cm.

 

Orders and Financials

The launch of the Boeing 777X became a record-breaking launch acquiring 259 orders (66) and commitments (193), valued close to $100 billion.

Table 1: Total and unfilled orders for the 777

Type	Total	Unfilled
777-200	88	0
777-200ER	422	0
777-200LR	59	2
777-300	60	0
777-300ER	721	250
	1350	252

Looking at the current 777 family, it can be seen that only the 777-300ER has a significant amount of unfilled orders, making an introduction of the 777X necessary to keep the 777 production line alive. Taking into account that Boeing has a backlog of 5100 airplanes valued $374 billion, it can be said that the contribution of the Boeing 777X to the order book is significant. I expect that in the coming years this number will grow even further as airlines will replace their 777/747 and start ordering airplanes to grow the fleet.

 

Conclusion

When it comes to timing the service entry and the launch of the 777X, I think Boeing did quite well (not accounting the 2 year gap that Boeing has.

Boeing's orders might be boosted by:

1. End of life cycle of the current generation Boeing 777 aircraft
2. Popularity of the Boeing 777 family
3. Increased demand for long haul aircraft
4. Airlines ordering aircraft from both Boeing and Airbus to acquire discounts and keep alive the duopoly

 

Boeing stock

 

Stock price Boeing 

 

Boeing's stock has risen almost 40% in 1 year. On the short term I don't think the 777X will add to the Boeing stock price, but the 777X gives Boeing a strong position on the long haul market, justifying higher stock prices on the longer term.

Source: Seeking Alpha