Boeing 777

1 Introduction

Man has been amazed by the concept of flight and has proceeded to formulate plans, experiment and finally implement and develop flying objects such as airplanes able to carry people and loads across huge distances while travelling at high speeds. The advent of flight and airplanes can be traced through history from mythical stories in Greece, India and Egypt to the actual Wright brother’s first airplane and the present sophisticated aircraft models such as the stealth fighter jet and the Boeing 777 (Vivian 4-9). Generally, airplanes can be viewed as vehicles with the ability to fly, with major support from air, the atmosphere and the associated forces as well as the airplane’s machines which includes the wings and the fuselage among others.

The Boeing Company produces the Boeing series of planes which includes the Boeing 737, 747, 777 among others. Boeing Company has been in operation for a long time, catering to governments as well as private individuals and has managed to continuously improve the Boeing model (Ismail par.2-5). The Boeing 777 mainly has two versions, the 777-200ER and 777-300ER. It is considered to be the largest twin-engine airplane in the world with the ability to fly 300 to 500 passengers over long distances. Its development began in the 1980’s and has gone through a variety of improvements to its present state (Airliner Gallery par.1-6).

2.0 Structure

The Boeing 777-200ER structural specifications include: Wingspan: 60.93 m (119ft 11in). Length: 63.73 m (209ft 1in). Height: 18.51 m (60ft 9in). Empty weight: 142,900 kg (315,000 lb). Maximum take-off weight: 297,550 kg (656,000 lb). Accommodation: 301-440 passengers. Range: 14.260 km (7,700 nm). Operating speed: Mach .84 (905 km/h, 490 kts). Engines: P&W PW4090 (400 kN - 90,100 lb) or RR Trent 895 (420 kN - 5,000 lb), or GE GE90-94B (410 kN - 94,000 lb). Conversely, the Boeing 777-300ER – Specifications include: Wingspan: 64.8 m (212ft 7in). Length: 73.86 m (242ft 4in). Height: 18.70 m (61ft 5in). Empty weight: 166,881 kg (366,940 lb). Maximum take-off weight: 357,534 kg (775,000 lb). Accommodation: 365 passengers (3-class). Range: 14,685 km (7,930 nm). Operating speed: Mach 0.84 (905 km/h, 490 kts). Engines: GE GE90-115B (512 kN - 115,300 lb) ((Airliner Gallery par.9-11).

2.1 Type and Method of Construction

Construction of the Boeing 777 first undergoes through a digital design and planning process and ultimately ends with the physical assembly of different parts from suppliers such as aerospace contractors located all over the world. The planning stages include digital pre-assembly where all the processes inherent in the production process are laid down from product definition  and planning for engineering and manufacturing material requirements to financial planning and customer service. The next phase involves the actual building where materials are ordered for purchase, operational control maintained as well as carrying out assembly inspection. Additionally, testing and eventual delivery is arranged and customer support services availed by ensuring delivery of high quality products with reduced costs (Glende 5-7).

2.2 Internal Structure

The Boeing’s 777 interior structure features curved panels, indirect lighting and large overhead bins. Seating arrangements include six seats in a row in the first class section and up to 10 seats across in economy class section with 15-inch by 10-inch windows. The Boeing also has overhead crew rests located above the main cabin. They are connected with the main cabin by staircases where the forward flight crew rest contains two seats and two bunks with the aft cabin crew rests featuring multiple bunks. The cabin has enough space for movement and the various facilities required such as lavatories (Elmershedi par.5-6).

3.0   Airframe Systems

Generally, the airframe of airplanes refers to their mechanical structures and includes the wings, fuselage and the undercarriage. The Boeing’s airframe systems include the six-wheel undercarriage, the wings, and the fuselage. The Boeing’s wings feature a supercritical airfoil design which is swept back at 31.6 degrees and optimized for cruise speeds of Mach 0.83. They help the plane to effectively balance in air by action of forces in the air, while the design material prevents its destruction from intense atmospheric pressure, considering the airplane’s high speeds. They are manufactured with increased thickness and a long span leading to a greater payload and range, a higher cruising altitude as well as improved takeoff performance.

On the other hand, the B-777 airframe incorporates durable lightweight composite aircraft structures, including graphite-epoxy floor beams, flaps and tail assembly. Additionally, the airframe’s composite materials comprise nine percent of its original structural weight. The main fuselage is circular in its cross-section and tapers towards the back into a blade-shaped tail cone. This creation of the fuselage tapering into blade-shaped tail helps to further stabilize the plane while in the air. It forms the main body which is made up of the flight deck, the cargo hold and the passenger’s cabin. Additionally, the plane has one of the largest landing gear as well as tires ever used in a commercial airplane with each of the tires of the Boeing 777-300 six-wheel main landing gear carrying a load of almost 27 tons (Elmershedi par.5).

As such, the plane requires careful and comprehensive maintenance of the fuselage and wings as well as other parts of the planes in order to avoid the plane disintegrating in the course of flights. Any problems should be effectively handled by the maintenance engineer to further ensure the plane’s safety. Any repairs require appropriate expertise considering the delicate nature of these airframe systems and the adverse environmental conditions they are subjected to.

4.0 Electrical System

The Boeing’s electrical system is composed of two independent electrical systems, one being the main system and the other one the backup system. The main system has two engine- driven integrated drive generators, a bus power control unit, a generator driven by the auxiliary power unit as well as three generator control units. On the other hand, the backup system incorporates two engine-driven generators with a single integrated converter/control unit which provides the redundancy of electrical sources equivalent to that of a three-engine airplane. The systems are automated, controlled by state-of-the-art microprocessor-based control units. The functions of the control units include system control and protection in addition to built-in-test functions (Andrade & Tenning 4-6).

Every control unit in the system is equipped with a redundant two-way communication facilitated by the newly-developed ARlNC 629 communication bus. Additionally, the control units utilize the communication bus to communicate among themselves to provide many control and protection functions in addition to the aforementioned monitoring functions to the Boeing’s information management system computer. Utilizing the communication bus significantly reduces the number of discrete wires required for similar systems and hence allowing substantial reduction of the interface circuits in use and reduction in weight. The system also has an emergency generator driven by a ram air turbine (Andrade & Tenning 5-7).

Generally, the Boeing’s electrical power system provides increased redundancy facilitated by the three main generators, two backup generators and one standby ram air turbine-driven generator in addition to four permanent magnet generators in satisfying the fly-by-wire and ETOPS requirements. The onboard centralized maintenance system is designed to enable maintenance engineers and line mechanic in facilitating rapid problem resolution as well as return to service. Essentially, reliable and redundant systems with the enhanced functionality and extensive coverage of the maintenance system enable the Boeing 777 to function effectively and efficiently (Glende 5-3).  

For the maintenance engineer, the planes electrical system poses a lot of problems and therefore requires a professional to handle any arising problems. The various issues that may crop up include the failure of the generators due to inadequate power supply as well as due to interference by adverse environmental conditions especially storm. The automated systems may also disintegrate amid flight therefore presenting major problems for the airplane. The back up electrical system may also be loose, preventing automatic resumption of power needed to operate the plane. The control units being pivotal to the operation of the planes entire electrical systems may fail to communicate to each other due to interference which means that the plane cannot utilize the automated electrical systems.

5.0 Avionics System

Sustenance and control of balance in the air by airplanes is achieved by the presence of wings and the numerous forces acting on them. However, due to increases and enhancements in technology, highly sophisticated electronics are being used to augment balance and control of aircrafts. These electronic systems of aircrafts are referred to as avionics, a term derived from the word aviation electronics. The systems include internal sensors and control systems, flight control systems, airborne communication, monitoring and navigation systems (university of Liverpool par.1-2). Other vital electronic systems include collision-avoidance systems, aircraft management and weather systems as well as black boxes.

The Boeing 777 avionics includes flight management and thrust systems, control maintenance and data communication systems, airplane conditioning monitoring as well as flight data recording systems. These systems are encased in two avionics cabinets which consist of eight line-replaceable modules each. The lines include four input and output modules and four core processor modules which use a common software and hardware architectural model. This system has reduced and reliable power and weight consumption with simplified system interfaces in addition to improved fault isolation. To ensure enhanced communication between all electronic systems with advanced functionality and reliability as well as weight and cost effectiveness, the system is equipped with a new multi-transmitter data bus, the ARINC 629. Necessary software is carried on board and is loadable in order to ensure functionality improvement in flight is incorporated faster while reducing overall spare costs (Glende 5-3).

6.0 Conclusions and Recommendations

To conclude, as is evident above, the Boeing 777 plane is quite sophisticated with enhanced features that enable it to cruise at high speeds as well as carry huge loads and people at the same time. This has been achieved through continuous improvement as well as efficient production and testing of the plane through technology and in anticipation and solving of potential problems and challenges. Considering the significant increases in the area of technology and management practices in general, I would recommend the owners of the Boeing model, although efficient up to this date to continuously stay apprised of new and innovative technologies especially in engineering and marketing. This will serve to ensure the owners are ahead of the existing as well as the potential competitors.