an electronic ight
instrument system
(EFIS) ‘glass’
cockpit, and greater
use of composite
materials. It
entered service
with Delta in
January 1988. A
150 of this variant
were built.FUEL COSTS
The Arab-Israeli
con ict of the
1970s resulted an
Arab oil embargo on supplies to countries
supporting Israel in 1973. There was another
oli crisis in 1979 due to the Iranian Revolution
though by the 1980s the price had fallen to
1973 levels.
However, the initial increase in the price
of fuel had seen a three-fold increase. As
part of NASA’s Advanced Turboprop Project,
which started in the mid-1970s in response
to the increasing fuel costs, General Electric
developed its GE 36 Unducted Fan (UDF)
engine. This was a standard F404 unit
coupled with advanced ‘propfan’ propeller
blades in a unique gearless contra-rotating
con guration that was claimed to reduce fuel
consumption by 32%. Flight testing with the
powerplant tted in place of the port JT8D on
an MD-80 was successfully carried out during
1987, with the eventual aim of introducing
UDF-powered aircraft into airline service in
late 1991. Two variants would have been
produced: the MD-91 (with 115 seats) and
the MD-92 (with 155 seats). These would
have been the world’s rst propfan-powered
transports in service, but the ending of the oil
embargo brought about a drop in fuel prices,
and a lack of airline interest in a ‘propeller’
airliner meant that the high development
costs could no longer be justi ed.
In August 1993 the MD-90 made its rst
ight. This was a slightly stretched version
of the MD-80, re-engined with IAE V2500-
D5s and introducing an advanced ight deck
with an EFIS t, a full ight management
suite, a state-of-the-art inertial reference
system, and LED dot-matrix displays for
engine and systems monitoring. The aircraft
also featured a redesigned passenger
cabin and carbon brakes. Delta was the
launch customer for the MD-90, with a rmcommitment for 50 and options on a further- It eventually operated 63 MD-90s and
two MD-90ERs (the latter version had a
higher gross weight and an auxiliary fuel tank
giving extra range). When Boeing merged
with McDonnell Douglas in 1997 the airline
cancelled the orders for the remaining MD-
90s and bought 737-800s instead.
The MD-90 also found favour with Saudi
Arabian Airlines, which ordered 29. It was
constructed on the same Long Beach
assembly line as the MD-80.
In October 1995 the MD-95 was
launched as an intended 106-seat DC-9-30
replacement, powered by two Rolls-Royce
715 high-bypass-ratio engines. Production
went ahead on the strength of a single order,
from Florida-based ValuJet (later renamed
AirTran Airways). In August 1997 McDonnell
Douglas merged with Boeing, leading to the
re-designation of the MD-95 as the Boeing
717-200. The company believed that the
100-seater market was buoyant enough at
that time to support both the 717-200 and
its own 737-600, with the 717 being more
pro table on shorter, regional services and
the 737 on longer routes. The rst ight of
the Boeing 717 took place on September
2, 1998, and the following year the 717-200
became the rst commercial aircraft to be
awarded joint certi cation by the US FAA
and Europe’s Joint Aviation Authorities (JAA).
AirTran Airways took delivery of its initial
717 in September
1999.
Before the
merger, McDonnell
Douglas had set
up an additional
plant in Shanghai,
China, for 40
(later reduced to
20) MD-90s to
be assembled
under contract
as the MD-90T
Trunk Liner. By
September
1999, 134 MD-
90s had been ordered. But the con ict of
interests with Boeing’s own established and
successful 737 family led to a decision to
phase out the MD-90, and only two examples
were built in China. As a result of the merger,
Delta cancelled its order for the remaining
19 MD-90s still to be delivered and opted for
737-800s instead.
No further orders for the MD-90 were
accepted, and production at Long Beach
ended in 2000, after 116 examples had been
delivered, the last one going to Saudi Arabian
Airlines. Production of the 717 continued,
with the type being built on the same moving
assembly line as the 737 from 2001. By then,
the 717 was facing increased competition
from new Bombardier and Embraer products,
and sales slowed. In December 2003
Boeing lost out in the battle for a $2.7bn
order from Air Canada, and in January 2005
the company announced that it planned to
end production of the 717 once outstanding
commitments had been ful lled.
On May 23, 2006 Boeing handed over
the nal two aircraft to Midwest Airlines
and AirTran Airways in a ceremony at Long
Beach. A total of 156 examples of the
717 had been built. The type was the last
commercial aircraft to be made at the former
Douglas plant, which had been producing
aeroplanes since the 1920s.
By February 2018 Delta was still the
largest user of DC-9 derivatives, with a eet
of 113 MD-88s, 65 MD-90s and 91 Boeing
717s. Other operators of the 717 worldwide
included Qantas Link, Volotea, and Hawaiian
Airlines. Earlier models of the MD-80
series are still active in some numbers, with
operators such as Far Eastern Air Transport
and Las Vegas-based Allegiant Airlines.http://www.aviation-news.co.uk 61A Boeing 717-200 of US carrier AirTran
(originally known as ValuJet). Before the
Boeing merger with McDonnell Douglas in
1997 the aircraft was designated the MD-95.
Key CollectionSaudi Arabian Airlines acquired 29 MD-90s,
including the last one built. Key Collection56-61_dc9DC.mfDC.indd 61 04/04/2018 12:59