MIAMI – Today in Aviation, the Boeing 747-8F made its first flight, successfully completing its high-speed and taxiing tests, in 2010.
With the intention of designing and manufacturing a worthy replacement for the Boeing 747-400 in all its variants, the company had already begun to accumulate a series of ideas at the end of the 90s for the new line of the more famous Jumbo Jet. In fact, the idea was to present Stretch versions to compete with Airbus’ A3XX proposal, which later became the A380.
Boeing’s goal was to launch a 747X and a 747X Stretch, much more functional than any 747 in the -400X, -500X, -600X, and -700X versions.
The 747X would have been 70.6 meters long with a wingspan increased to 69.8 meters by adding a segment at the root.
Maintaining the same 6.5-meter width of the fuselage and the same maximum height of 19.4 meters, the 747X could carry 430 passengers for an impressive 16,100km (8700 NMI).
As for the 747X Stretch, while maintaining the same wingspan, width and height as the 747X fuselage, the length was increased to 80.2 meters allowing it to carry up to 520 passengers for more than 14,400km (7,800 nmi). Finally, there were two engines planned: Engine Alliance GP7200 (engine of the A380) and the Rolls Royce Trent 600. A cargo version was also planned for the 747X.
The Launch of the 747-8 in 2005
After a series of rumors of a possible 747X series development program, Boeing announced in early 2004 that plans for a 747 Advanced had begun. Similar to the 747X, the Advanced series would use the technology tuned for the 787 DREAM)LINER to make the design more modern. On November 14, 2005, Boeing announced that it was launching the production of the 747 Advanced under the name 747-8.
Noeing did not take for granted the evolution of the project because at that time only Lufthansa (LH) had the 747-8i on order. In October 2009, Boeing announced a delay of the first flight of the 747-8F until the first quarter, and consequently also delayed its delivery. Due to this delay, Boeing announced a loss of US$1bn. Net of this loss, Cargolux Airlines (CX), the launch customer of the -8F program, confirmed its order for 13 units and LH confirmed its commitment to the passenger version.
On November 12, 2009, Boeing finally announced the rollout of the first 747-8F, which was immediately sent to the paint shop at the company’s Everett plant. On December 4, 2009, Korean Air (KE) became the second airline to order the 747-8i with an order of five units. KE also announced an order for two cargo models in March 2011.
On April 21, 2010, Jim McNerney announced that Boeing was accelerating production of both the 747 and 777 variants to support the growing demand.
Flight Test and Certifications
The Boeing 747-8F completed track engine tests in December 2009 and on February 7, 2010, successfully completed high-speed and taxiing tests. The second test flight took place in late February with a transfer flight to Moses Lake to test its new navigation equipment. By March 11, 2010, the Boeing 747-8F had completed 13 flights for a total of 33 flight hours.
Also on March 15 of that year, the second Boeing 747-8F made its first test flight at Paine Field (BFI), where it briefly stationed on the base before moving to Palmdale to continue flight tests with the first prototype. On March 17, the third -8F joined the test program with its first flight.
On April 19, 2010, the second aircraft was moved from Moses Lake to Palmdale to conduct tests on the aircraft’s engines in preparation for the aircraft’s certification. On 3 June, during the tests, a tractor towing the plane damaged the nacelle of an engine without causing any damage to the engine itself.
On June 14, 2010, the Boeing 747-8F completed the initial flight test phase and the FAA initiated an extensive certification check for the aircraft. By the end of June that same year, the three -8Fs employed in Boeing’s flight test program had totaled 500 flight test hours and completed high-temperature endurance tests in the state of Arizona.
At the same time, Boeing claimed that a fourth 747-8F was required to complete the tests, thus opting for the second production aircraft in CX livery to conduct non-instrumental tests. On August 21, 2010, in Victorville, California, the 747-8F was tested for take-off outside the maximum weight: the aircraft took off despite weighing 455,680kg, compared to a certified maximum weight of 442,253kg.
Lastly, on August 19, 2011, following further delays, the FAA and EASA jointly issued the homologation certificate for the Boeing 747-8F.
Not meeting expectations, the Boeing 747-8 created discontent among the ordering companies. To remedy this, and to create attraction towards the aircraft, Boeing presents a package of improvements under the name of “Ozark Project” in mid-2014. Some of these improvements have already been introduced, others will be released according to market needs.
The best ones already operational concern:
- Engines: these have benefited from the PIP package, Performance Improvement Package which, thanks to an update of the electronic engine management, improvements to the fluid dynamics in the AP (high pressure) compressor and BP (low pressure) turbine and new ice bleed valves, consume less fuel and eliminate the formation of ice during the crossing of clouds in the cruise flight;
- Autonomy: thanks to the activation of the tanks in the queue, the autonomy of the type rose to 15,200km;
- Avionics: improvements to the display system and flight management software gave way for a more efficient cruise altitude climb and more precise navigation;
- MTOW: savings of approximately 5,440kg thanks to structural improvements
- Consumption: thanks to the PIP package, fuel consumption improved by 1.8%, which in combination with weight reduction and structural improvements, have resulted in an increase in efficiency of 3.5%.
The aircraft, with a maximum take-off weight (MTOW) of 448,000kg, guarantees a payload of 140,000kg and a range of 8,130km. Compared to its predecessor Boeing 747-400F, it can carry four more pallets on the main deck in addition to three more pallets on the lower deck. Furthermore, Boeing says the 747-8F guarantees savings of approximately 16% on the running cost per ton/mile.
The plane is 76.25 meters long, making it for a while the longest commercial aircraft in the world, surpassing the Airbus A340-600, which is 75 meters long. However, the length record was later beaten by the Boeing 777-9x, which is 77 meters long. The height of the 747-400F is 19.4 meters with a wingspan of 68.45. The empty plane weighs 295,000kg and the MTOW weight is 448,000kg. The type is powered by four GE GEnx 2B-67/2B67-B/2B67-P thrusters.
A New Engine Shared with the Boeing 787
The General Electric GEnx, or General Electric Next Generation, is a family of turbo-fan engines developed and produced by GE aviation. The engine is installed on both the Boeing 747s and 787s and were developed based on the GE90 and intended to replace the famous CF6. This engine re-purposes technologies already present on the GE90, namely the fans made with composite material, the fan casing and the compact compressor.
The peculiarity of this engine is that, on the Boeing 787, it has the same interface connections with the aircraft as the alternative engine, namely the Rolls Royce Trent 1000. The GEnx is produced in two versions:
- GEnx-1B (in three variants for the Boeing 787-8, -9, -10)
- GEnx-2B67 for the Boeing 747-8.
These engines offer many innovative technologies, in fact in the high pressure compressor there are: a VIGV system, Variable Inlet Guide Vane, at the inlet and a VSV system, Variable Stator Vane, in the first 5 stages.
A Modular Approach
The engine is built according to a modular philosophy, which allows each individual engine module to be revised independently from each other. This thruster is started via an electric motor connected to the accessory box. This in fact reduces the weight of the engine itself, which together with the fan blades and the crankcases, both made of composite material, led to a saving of 159kg in terms of weight. In addition to the weight, the high by-pass ratio has allowed an engine reduction of 13db compared to the GE90.
To increase the energy efficiency of the engine, the ten stages of the high-pressure compressor guarantee a compression ratio of 43:1.
Sensors have been installed in the engine that are able to monitor every single part, to monitor the operating parameters and communicate them to the EMU, Engine Monitoring Unit, which monitors them in real time, allowing to keep track of the performance trend in the period of operation.
In addition, the engine is equipped with the FADEC III system for automatic management of operating parameters. Engine features include:
- Maximum thrust: 30,164.4 kg
- Compression ratio: 43: 1
- Fan diameter: 268cm
- External diameter: 323.4 cm
- Fan blades: 18 in composite material
- Length: 469.9 cm
- Dry weight: 5,614.2 kg
Featured image: Boeing first 747-8F as N747EX. Photo: Phil Wilco/Airways