COMMERCIAL BOEING 777
T
he Boeing 777 is the
largest twin-jet airliner
ever produced. From its
October 1990 launch to
the time of writing in early
August 2017, a total of
1,935 examples had been
ordered, of which 1,502
had been delivered.
The landmark 1,500th
jet, 777-322ER N2243U (c/n 63723), was
delivered to United Airlines in July – a neat
historical symmetry given this carrier was the
first to put the 777 into service in June 1995.
The 777 family
Six Triple Seven variants have entered
service to date: the 777-200, the 777-200ER,
the 777-300, the 777-300ER, the ultra-long-
range 777-200LR and the 777 Freighter.
Two new variants, the 777-8 and 777-9, are
currently under development in the 777X
programme launched in 2013. The first 777-9
is scheduled to fly in 2019 and following
certification enter service in 2020.
The 777-300ER is the stand-out performer
from a sales perspective. By August 2017
it accounted for 819 of all Triple Sevens
ordered. Boeing has sold 422 777-200ERs,
59 777-200LRs and 161 777Fs. The 777Xs
have secured 326 orders so far. Of the out-
of-production models, the company sold 88
777-200s and 60 777-300s.
Key reasons for the 777-300ER’s
particular success include its 7,370nm
(13,050km) range, high capacity (396 seats
in a standard two-class configuration), twin-
engine economics and 7,120ft^3 (201.6m^3 )
of lower deck cargo capacity, which gives
operators valuable incremental revenue-
earning opportunities.
Triple Sevens have been delivered to more
than 60 operators worldwide. Emirates has
more in service than any other airline, with
142 as of early August 2017. Other carriers
flying the type in large numbers include
United Airlines (88), Air France (70), Cathay
Pacific Airways (70), American Airlines (67),
British Airways (58), Qatar Airways (55) and
Singapore Airlines (53).Performance
improvement package
With a popular product on its hands and such a
large installed customer base, it isn’t surprising
Boeing has sought to improve the 777’s
performance over the years.
In 2009, the company introduced a
Performance Improvement Package (PIP)
for the 777-200, 777-200ER and 777-300.
At that time, although production of the
777-200 and 777-300 had ended and the
777-200ER’s orders backlog was dwindling
(there are currently no unfilled orders but
Boeing still markets the variant, hence its
inclusion on the characteristics table in thisfeature), it was realised some technologies
developed for the 777-300ER were
retrofittable to these earlier models.
The 2009 PIP for the 777-200, 777-200ER
and 777-300 introduced three key changes. The
first was an upgraded ram-air turbine system to
provide improved control of airflow and thrust
recovery. The second change was a drooped
aileron, a software-based modification designed
to create a higher aerodynamic loading on
the outboard wing to make the loading more
elliptical and cut drag. The third change was the
replacement of 32 vortex generators by smaller
737-type vortex generators to further reduce
drag around the wing.
Boeing said the 2009 PIP provided a
1% fuel burn improvement and an annual
reduction of CO 2 emissions of more than
3,000,000lb (1,360,800kg) compared to the
first 777-200s, 777-200ERs and 777-300s.777-300ER aerodynamic
optimisation
After the 2009 PIP, Boeing
engineers turned their attention to
improving the 777-300ER, 777-
200LR and 777 Freighter. Changes
for these models in three areas- aerodynamics, weight and the
GE Aviation GE90-115 turbofan
engines – were subsequently
brought out into a PIP announced
in 2015.