Douglas DC9
The Douglas DC-9 is a twin engine jet airliner, first manufactured in
1965 and, in much modified form and under a succession of different names,
still in production today as the Boeing 717.
Douglas launched the DC-9 development project in April, 1963, intending
the DC-9 as a short-range companion to their larger, four engine DC-8.
Unlike the competing but slightly larger Boeing 727, which used as many 707
components as possible, the DC-9 was an all new design using two rear-mounted
Pratt & Whitney JT8D fanjet engines, a small, highly efficient wing, and a
T-tail. The original version had five abreast seating for 70 to 90.
The DC-9 prototype flew in February, 1965, and entered service with Delta
Air Lines in December of that year. It was an immediate commercial success
and 976 were built by Douglas who then merged with McDonnell Douglas (MDC).
In 1983, the world saw the advent of the DC-9-80 series (MD-80) which was a
lengthened DC-9-50 with a higher MTOW (maximum take-off weight) and the ability
to carry more fuel. The MD-80 was then developed into the MD-90 family.
The MD-90 sports IAE V2500 engines and a glass cockpit as does the MD-88. The
last variant of the family was the MD-95 which is now marketed as the Boeing
717-200, in light of the merger between MDC and Boeing in 1997.
With total sales of over 2400 units, the long-lived DC-9 family is one of the
most successful jet airliners ever made, ranking third behind the Boeing 737
(over 5100) and Airbus A320 family (just under 3000).
DC-9 models
DC-9-10 The earliest and smallest DC-9 was 27 m long and had a maximum weight
of 41 tonnes. Power was a pair of 54.5 kN Pratt & Whitney JT8D-5s. 137 were built.
The DC-9-15 and DC-9-20 were minor variations on the -10 theme. The -15 added
more fuel capacity and higher weights, the -20 used the more powerful engines
and improved wings of the -30 to improve hot and high performance. Only a small
number of each were made.
The DC-9-30 was the definitive model with 662 eventually produced. The -30
entered service in February, 1967, with a 4.5 m fuselage stretch, wingspan
increased by just over 1 m, weight increased to 55 tonnes, and 64 to 67 kN
JT8D-9 or JT8D-11 engines. About 380 -30s remained in commercial service in 2002.
Many of these 30 (with side cargo door) types were utilized by the military in
C-9A Nightingale Medivac configuration for the U.S Air Force and the C-9B
Skytrain II version used by the U.S Navy and Marines for fleet logistics support.
Many of these types were fitted with additional fuel tanks
installed in the lower cargo hold to augment the aircrafts range for overseas
missions along with Infra-red (IR) scramblers to counter heat seeking missile
threats in hostile environments.
The further stretched DC-9-40 entered service with SAS in March, 1968.
With a 2 m longer fuselage, accommodation was up to 125 passengers. The -40 was
fitted with a variety of Pratt & Whitney engines of between 64.5 and 71 kN. 71
were produced.
The largest DC-9 to fly under that name was the DC-9-50 which has another 2.5 m
fuselage stretch and seats up to 139 passengers. It started revenue service in
August, 1975, and, aside from the size increase, included a number of detail
improvements, a new cabin interior, and quieter JT9D-15 or -17 engines in the
70kN class. McDonnell Douglas delivered 96.
Typically known as the MD-80, the next members of the DC-9 family were the
-81/-82/-83/-88 and the shortened MD-87 series. The MD-80 designation was a
marketing move to show that McDonnell Douglas had an airliner for the 1980s.
The "Series 80" versions sport cockpit, avionics, and aerodynamic upgrades
along with the more powerful, efficient, and quieter JT8D-(200) series engines,
which are a significant upgrade over the smaller JT8D-15, -17, -11, and -9 series.
The DC-9-80 series aircraft also have longer fuselages than their older DC-9
counterparts as well as an increase in range. The MD-80's production ended in 1999.
The MD-90 was introduced in 1993, and was basically a 1.4 m longer, updated
version of the MD-88 with a similar EFIS (glass) cockpit and even more powerful,
quieter, and fuel efficient engines than the MD-80 models, the IAE V2500 Series
engines. MD-90 production ended in 2001, with the last MD-90's being built under
contract in China.
The Boeing 717 was slated to wear the MD-95 badge until Boeing and McDonnell
Douglas merged in 1997. This variant is the last update to the DC-9 airframe
family. The MD-95 program was renamed and the Boeing 717 entered service in
September, 1999. The aircraft is 1.45 m longer than the DC-9-30 and has the
same basic cockpit and cabin updates as the MD-90 but is powered by new
Rolls-Royce BR715 engines. The B-717 is to end production in 2005. It will be
the end of the civilian Douglas aircraft in production.
This article is licensed under the
GNU Free Documentation License.
It uses material from the
Wikipedia article "McDonnell Douglas DC-9".
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