1. The Mcdonnell : Douglas MD-80
I
Fuselage stretchability, naturally incorporated in the fundamental DC-9 design, acquired
characterized its plan, resulting in four dimensionally divergent, higher-capacity versions, including
the initially-elongated DC-9-30 over the baseline series -10/14/15, the subsequent DC-9-40, and the
final DC-9-50, the latter accommodating forty nine more passengers as opposed to twin-jet's original
maximum.
The DC-9 themselves, founded upon the 4 design tenets associated with ruggedness, simplicity,
stability, and low-cost, was McDonnell-Douglas's best-selling professional aircraft-so much so, in
reality, that it took off as well as landed somewhere on the globe every seven just a few seconds,
serving more than 570 cities with some some,050 daily routes, and by 1979, your collective fleet
acquired carried more than one billion dollars passengers and drenched more than 18 thousand
hours with an nearly 99-percent dispatch stability rate.
Its Pratt and Whitney JT8D engine, the most popular powerplant and numbering in excess of 12,500
units, had not only provided propulsive thrust for all versions of the DC-9, but had also powered the
particular Boeing 727, the Sud-Aviation SE.210 Super Caravelle, the Boeing 737, and also the
Dassault-Breguet Mercure 100.
Both the DC-9's basic design and its JT8D turbofan therefore offered the most the best possible, cost-
effective platform where to base any larger-capacity successor, which in turn needed to equal your
DC-9-30's range capacity, yet exceed the particular DC-9-50's economics.
Its fuselage, not having achieved its limit involving stretchability, lent by itself to still higher-capacity
accommodation, but its obstacle had been a powerplant of sufficient forced to maintain acceptable
payload, range, and performance guidelines for its operators.
Based upon the earlier, two-stage JT3D, which had run both the 707 along with the DC-8, the JT8D,
a low, one-to-one sidestep ratio turbofan, got first run on the spring 7, 1961, using to the skies the first
time on May one of the following year installed to a 707. Getting FAA certification last month 9, 1963,
since the 14,000 thrust-pound JT8D-1, it had powered the 727-100 before being employed from the
DC-9-10 and ended up being subsequently offered in many successively higher-thrust variations, the
last of which had recently been the 17,500 thrust-pound JT8D-17R.
A new-generation variant, supplying application for an best DC-9 stretch as well as designated JT8D-
109, have been one of six exhibition powerplants incorporating more substantial, single-stage fans
created for NASA's quiet Engine Program, which in fact had run between 1972 and 1975, and a
couple of its versions experienced logged more than 50 hours retrofitted with a modified DC-9-32.
Design and style of a further improvement, the 18,five-hundred thrust-pound JT8D-209, started in
1974 and first ran 2 yrs later, test flown on a McDonnell-Douglas superior Medium STOL
transportation (AMST) in 03 of 1977.
Although a new, supercritical wing had also initially been considered, your aircraft, intended for short-
to medium-range areas which entailed increased ratios of climb-and-descent to actual cruise trip

2. profiles, could not totally exploit such a new design, its advantages resultantly unable to make a case
for its higher improvement costs. The existing DC-9 wing, incorporating actual and tip exts and
modified high-lift devices, would provide the necessary performance, economy, as well as range
parameters.
Several initial iterations, largely based upon the DC-9-50 and all featuring fuselage stretches for
higher capacities, larger-area wings, and two refanned turbofans, had included the particular refan-
stretched DC-9-50RS, the actual refan-super stretched DC-9-50RSS, the DC-9-55, along with the
DC-9-60, while any DC-9QSF, intended for japan operators as an NAMC YS-11 twin turboprop
replacement, mated a new DC-9-40 airframe together with two 18,500 thrust-pound JT8D-209 motors
and a two-foot bigger wing, enabling the 114,000-pound plane to operate from 4,000-foot runways
along with 120 passengers.
However, cost constraints and design complexities dictated a simpler, more straightforward version
which incorporated the longer fuselage, increased-area wings, and JT8D-209 turbofans, yet retained
cockpit commonality with all previous DC-9 variants. Skipping both the DC-9-60 and DC-9-70
sequences, the specified aircraft, designated DC-9-80-or DC-9 Super eighty, to more accurately
mirror the intended calendar year of service inauguration-had been launched on april 20, 1977 while
using receipt of twenty-seven firm and 13 optioned orders from Swissair, Austrian airlines, and
Southern air passages, along with a letter of intent from LAV Lineas Aeropostal Venezolanas, all of
which had been past DC-9 operators. Imagined as a higher-capacity accentuate to its DC-9 airframe
and a replacement higher-cost tri-jets, this intended to provide support in maturing marketplaces
whose environmental along with noise restrictions had precluded larger-capacity products
substitution, the plane offering a substantially smaller noise footprint, greater range as well as
capacity, and the cheapest seat-mile costs involving any comparable twin-jet.
According to then-President of the Douglas planes Company, John c. Brizendine, "In recent
years...we now have become acutely alert to the need to conserve electricity, to protect the
environment, also to produce more and more monetarily efficient aircraft. (the particular DC-9 Super
70 ) is specifically designed to fulfill the requirements of our industry for years to come. For instance,
environmental compatibility, electricity efficiency, economical procedure, and a spacious, comfortable
interior."
McDonnell-Douglas featured of the aircraft, "the particular DC-9 Super 80 is a blend of confirmed
design with accessible low-risk technology with regard to enhanced effectiveness, (but ) the
remarkable DC-9 reliability and lower functioning costs are managed."
Although it had been considering this earlier-generation double, it nevertheless released several
advanced capabilities.
A fuselage expand, attained by means of a good eight-frame plug onward of the wing along with a
single-frame insertion aft of it, resulted in any 147.10-foot overall length, increasing optimum capacity
to 172, or 33 over the DC-9-50 and also a staggering 82 more than the initial DC-9-10, and producing
the most massively stretched commercial airliner up to that time. The particular forward, left, and aft,
ventral, exits, both equipped with extendible airstairs, had been stored, but an aft, left servicing

3. doorway, located only ft from the engine, ended up introduced. Aeritalia involving Naples, Italy,
produced its fuselage sections.
A new, 10.6-foot center section and two-foot parallel-chord tip extensions, inducing the third
dimensionally divergent DC-9 wing, gave a 28-percent region, 57-percent fuel capability, and 11-
percent efficiency increase.
Measuring 107 feet, 10 1/4 inches, the airfoil, with a 24-degree mop back at their quarter chord, any
9.62 aspect ratio, three examples of dihedral, and a a single,239 square-foot region, had been
comprised of several per-wing precision-machined skin color panels which had already been
transformed from 15,000-pound ingots calibrating 60 inches broad, 15 inches long, and 30 ins thick
by the Reynolds Metal Company of McCook, Illinois.
The all-metal, two-spar framework, with riveted spanwise stringers, featured full-span, three-position
leading edge slats with a new, intermediate environment to decrease take off move and improve
climb performance at greater gross weights; bigger, doubled-slotted, trailing side flaps which included
67 percent with the span and decreased the aircraft's stalling speed; three spoiler panels, the exterior
two of which had been employable as the two flight and soil lift dumpers; and ailerons. All but rogues
were hydraulically actuated, while the ailerons on their own were manually run. An underwing vortillon
fence ensured appropriate airflow. Providing one particular,520 US gallons of additional fuel tankage,
it also offered a great increased-area main undercarriage bay.
The variable-incidence, electrically-actuated horizontal butt, spanning 40.only two feet, or 3.6 feet
more importantly of the DC-9-50, retained the design's characteristic t-tail configuration along with
sported assister tab-equipped elevators, while the straight fin, rendering a general aircraft height
associated with 30.2 feet, featured a hydraulically-actuated rudder. It had been a single.4 feet greater
than the DC-9-50's.
Its Pratt and Whitney JT8D-209 turbofan, mounted on either side of the aft fuselage and keeping the
original target-type push reversers, was based upon the core from the earlier JT8D-9, nevertheless
introduced a 49-inch wider fan as well as an advanced, low-pressure compressor, producing 18,five
hundred pounds of thrust along with an additional 700 pounds of automated power reserve (annual
percentage rates ), generated during engine-loss conditions. The larger-diameter, single-stage fan,
driving a larger mass involving hot core section-bypassing air, coupled with more effective hot and
cold exit duct intermixing air, and also increased sound assimilation material in its nacelle and
surrounding outer shell, yielded numerous advancements, inclusive of increased forced capability; a
higher bypass ratio-of 1:1.78 as opposed to the earlier JT8D's 1:one particular ; a lower exit speed ;
an 11-percent reduction in specific fuel intake ; and a significantly scaled-down noise footprint than
that of the medium-range tri-jets it had been intended to exchange.
Employing weight-reducing Kevlar-reinforced aluminum honeycomb stiffeners with graphite video
tape caps in the exterior barrel of its nasal area cowl and its top and two lower include doors, the
nacelle, 21.1 toes long, was four.5 feet extended than the JT8D-9's and so presented engineering
problems relative to its installation on the DC-9's, even if longer, body.
The DC-9 Super 50 retained the hydraulically-retractable, tricycle, dual-wheeled, Cleveland

4. Pneumatic undercarriage, installed with Goodyear wheels, tires, and dvd brakes; Hydro-Aire Mk IIIA
antiskid devices ; and Douglas ran air brake air conditioning. The nose tyre was steerable to 27
degrees either to side.
Although the Super 80 kept a common pilot type rating with the DC-9, it nevertheless provided
several cockpit improvements, including a digital and flight guidance control system designed by the
particular Sperry Flight devices Division of Sperry Rand Corporation, which usually integrated the
overall performance of seven trip control subsystems straight into two identical electronic digital
computers; cathode beam tube (CRT) exhibits ; a digital fuel quantity gauge system; a new dial-a-flap
system; as well as Category IIIA autoland capability of 50-foot choice height (DH) along with 700 feet
of runway visual range (RVR). A later introduced Electronic performance Management System
furnished automatic pitch along with thrust to effectuate optimum speed and also fuel burn throughout
the aircraft's climb, sail, and descent profiles.
The 101-foot-long, "broad look" cabin, highlighted a broad, contoured, as well as sculpted
acoustically-treated threshold which blended along with the enclosable expense storage
compartments; light weight aluminum sidewall panels attractive round the windows; fluorescent
lighting; a 19-inch aisle; and five-abreast, two-three or three-two, configured economy type seating,
which reduced by half the quantity of middle seats usually associated with six-abreast agreements.
Interior decor, that varied from traditional, business-oriented appointment to be able to bold patterns
and also bright colors, had been determined by the operator and custom-designed through
McDonnell-Douglas whose interior planning teams often produced trips to flight home countries so as
to absorb local traditions and customs after which it convert that experience into area- or country-
reflective motifs. Wool and wool synthetic mixes were standardly employed for seat covers and
carpets.
Class and seating configuration similarly varied according to driver. A 137-passenger, dual-class
arrangement, for instance, required 12 four-abreast high grade seats at a 38-inch pitch and one
hundred twenty five five-abreast economy school seats at a 34-inch pitch, while single-class densities
included 155 passengers at a 32/33-inch pitch, 167 charter seats at a 30-inch pitch, or a more 172
high-density passengers, the latter accommodatable with a single galley installment.
Interior noise lessening was attained through an insulating umbrella of fabric-reinforced Mylar over
fiberglass.
The elongated DC-9 launched a new pressurization along with air circulation system, that replaced
cabin atmosphere at greater frequencies, and its potable water system featured in-line heaters in all
of their water lines. The increased-capacity auxiliary power unit (APU) ran its environmental handle
system on the ground.
The aircraft's longer fuselage significantly increased their lower-deck baggage and also cargo
compartment amount, whose forward, center, and aft contains respectively encompassed 434, 376,
and 443 cubic feet.
The DC-9-80 retained 80 % of the DC-9-50's important maintenance features.
Like all of its previous, shorter-fuselage predecessors, the actual aircraft had been designed for short-

5. sector, rapid-turnaround, self-sufficient operations from quick, limited-facility airfields, having its
increased thrust, larger-area wings, self-contained airstairs, auxiliary power system for environmental
health and fitness and engine starts, low-to-ground profile to facilitate servicing, packing, and
maintenance, as well as ability to operate two or more sectors without the need pertaining to
refueling. Most turnarounds required little more than suitcase carts.
With the maximum structural payload of 40,112 pounds, the DC-9-81, as designated in its initial
variant, stood a 147,000-pound major weight, although this ended up later increased for you to
149,500 lbs with uprated applications, and a maximum clinching weight of 128,000 pounds. The
normal and greatest cruise speeds have been, respectively, Mach 0.76 and 3.80. Range, using 155
single-class people and domestic supplies, was 1,564 nautical miles.
Piloted by Douglas main Engineering Pilot they would. H. "Knick" Knickerbocker, Project Pilot john P.
Laine, along with Flight Test engineer Virginia "Ginny" the. Claire, the first DC-9 Super 80 as well as
the 909th twin-jet to roll off the lengthy Beach assembly series, made its first flight from long Beach
Municipal Airport's Runway 30 in October 18, 1979 with call sign DACO 80-for "Douglas Aircraft
Company 80."
Following a 25-mile circular, overwater routine, the long, slender-fuselage aircraft, accommodating
tough luck,100 pounds associated with test equipment, completed a successful two-hour, 50-minute
basic-maneuvers test sortie before landing in McDonnell-Douglas's Flight surgical procedures Facility
in Yuma, Arizona, where the primary Engineering Pilot came to the conclusion, "The ground handling
of the Super 80 will be even better than the additional DC-9s. It also felt quite stable in flight...The
new engines ended up faultless, and the invert thrust was extremely effective on landing...i really
believe the Super 80 is a great airplane and will live up to all our anticipations."
The 1,085-hour, $36 million, three-aircraft flight test software, which entailed 1st flights of prototype
N1002G on 12, 6, 1979 along with N1002W on February twenty nine, 1980, led to faa certification
seven several weeks later, on july 26, under the amendment to the DC-9's original type qualification.
First delivered to release customer Swissair in September 12, which in fact had operated earlier DC-
9-15, -30, and -50 series, it was inaugurated into scheduled support on October five from Zurich in
order to Frankfurt, becoming the actual quietest commercial pure-jet. Co-launch customer Austrian
Airlines, which had just as operated a fleet of DC-9-30s and -50s, inaugurated its very first revenue
service a three week period later, on april 26, from Vienna to Zurich.
In order to adopt the particular McDonnell-Douglas designation scheme, the DC-9-80, as well as DC-
9 Super 80, was rebranded the particular "MD-80" in 1983, its initial version dubbed "MD-81."
II
Development of the baseline Pratt and Whitney JT8D-209 engine, resulting in the uprated, 20,000
thrust-pound -217, augmented further versions, the origin which had been the nineteen seventy nine
requirement for a short take off and landing (STOL) aircraft to operate inside the Japanese domestic
market. A then-projected time, designated DC-9 extremely 80SF, would have mated the DC-9-40's
fuselage with the DC-9-80's mentorship and engines, however the higher-thrust JT8D-217, placed on
existing fuselage proportions, would have provided a lot of the desired performance. Resultantly, a

6. second variant, selected MD-82 and very first announced on apr 16, 1979, featured the uprated,
30,000 thrust-pound turbofans with 850 lbs of automatic energy reserve, a 44,024-pound payload,
and also a 2,050-mile variety with 155 travellers. First flying in January 8, 1981, it received its FAA
type certification six months later, on July 31, with an initial 147,000-pound maximum take off fat,
although the 1982 selection of JT8D-217A motors further increased this specific to 149,five hundred
pounds, resulting in still-higher payload and selection capabilities.
Republic air carriers, the July 1, 1978 amalgamation of North Central and also Southern Airways,
have been the version's start customer, having been the world's largest DC-9 agent with series -10s, -
30s, and -50s, to which its eight MD-82s were sooner or later added.
The alternative had been involved in a pair of unique programs. The 1st of these, occurring inside
October of the early 80's, entailed the modern lease of 30 MD-82s to u. S. Airlines, for which
McDonnell-Douglas agreed to bear the maintenance and training fees. This let for the February 1984
purchase of 67 aircraft, at attractive prices with low cancellation penalties, to be delivered in blocks of
five to 25 airframes, each block that had been confirmable 24 months before the targeted shipping
date. Becoming the mainstay of American's short- to medium-range fleet to assist in hub connections
within Chicago and dallas, the aircraft, constructed for 142 very first and economy class passengers,
ultimately figures 234, the world's most significant, single-type total not in the former USSR.
The second innovative transaction occurred on 04 12, 1985, when the Shanghai Aviation professional
Corporation agreed to license-build 25 MD-82s in the People's Republic associated with China.
An extended-range successor, designated MD-83 and first announced on January thirty one, 1982,
introduced nonetheless higher-rated engines. Your JT8D-219, rated at 21,000 pounds regarding
thrust, featured any redesigned low-pressure generator, a new high-pressure turbine,
aerodynamically improved airfoils, a five-percent rise in thrust, and a two-percent reduction in fuel
burn.
First flying about December 17, 1984, the twin-jet, having a 160,000-pound maximum take off weight,
offered a 2,502-nautical kilometer range, attained with 1,160 people gallons of additional, decrease
deck hold-installed extra fuel tanks. Finnair, which had operated your DC-9-14/15, -40, and also -50,
served since the version's launch buyer, operating the best, nonstop MD-80 airline flight on
November 14, 1985, when that covered the 3,406-mile distance between Montreal and Helsinki within
seven hours, twenty six minutes. Transwede, regarding Sweden, inaugurated the very first revenue-
earning trans-Atlantic airline flight from Stockholm for you to Ft. Lauderdale using intermediate stops
in Oslo and gander.
In order to offer a lower-capacity counterpart considerably better to reduced-demand sectors, and to
more effectively tackle the 737-300 Boeing designed for this market, McDonnell-Douglas offered the
first, and only, dimensionally-divergent variant, the particular MD-87, which had evolved from its
earlier, DC-9 Super XX research for a 100- for you to 120-passenger aircraft run either by Pratt and
Whitney JT8D-200 series or CFM International CFM56-3 turbofans and offering a new 110,000- to
120,000-pound yucky weight. The version, with a 16.5-foot shorter fuselage, presented a new, 130.5-
foot overall length and had a 38,726-pound maximum payload, or same as the DC-9-50's.

7. Because of the reduced moment-arm of the quicker fuselage, vertical axis control required the larger-
area, ten-inch taller fin, visible from the extension above its traditional t-tail mating point and
producing a new, 31.2-foot overall height. What's more, it introduced low-drag flap hinges and
fairings, a fillet fairing between the fuselage as well as the engine pylon, along with a reduced-drag,
blade-shaped tailcone.
Initially powered through the 20,000 thrust-pound JT8D-217B, but later retrofitted with the reduced
fuel consumption -217C version, the MD-87 had a 2,372-nautical mile range along with 130
passengers and domestic reserves, although additional, MD-83 kind fuel tankage inside the lower
holds increased this to 2,833 miles.
First using to the skies about December 4, 1986, it received the FAA type certificate on October 21 of
the following 12 months, and was inaugurated into service about December 17 with Austrian Airlines
through Vienna to Zagreb.
The last, and a lot advanced, of the several versions, the MD-88, reintroduced the original fuselage
dimensions and had been announced on jan 23, 1986 after launch customer Delta Air Lines inserted
an initial order to be able to 80 of the variety. Offered with 21 years of age,000 thrust-pound JT8D-
219 turbofans, the version, most closely good MD-82, featured improved composite material to
relieve structure weight, a whole new passenger cabin having a wider aisle and modernized overhead
hard drive compartments, and an advanced, glass cockpit, the second comprised of an electronic
flight instrument system (EFIS), a flight management method (FMS), and the inertial reference
system (IRS). It kept the MD-87's blade-shaped tailcone.
First traveling on August fifteen, 1987 and FAA-certified four months afterwards December 9, the
particular MD-88 entered timetabled service with Delta on January five, or just over 25 years after it
had operated earth's first passenger-carrying service with the -14 sequence on December 7, 1965. It
got also operated your stretched DC-9-30 and the MD-82.
III
The 1,000th MD-80 had been delivered in March 29, 92, and by December associated with 1997, 1,a
hundred and fifty of the type have been in service with 62 worldwide airlines. The style, partially
succeeded by simply its advanced, re-engined MD-90 counterpart and also Boeing's own following
Generation 737 family after that manufacturer's acquisition of McDonnell-Douglas, nevertheless
became its best-selling pure-jet commercial airliner, exceeding sales of the DC-8, the Super DC-8,
the DC-9 themselves, the DC-10, the particular MD-11, the MD-90, and the MD-95/717, the past
delivery of which acquired occurred on 12, 21, 1999, when an MD-83 ended up handed over to TWA,
ending two decades regarding production. Combined with the 976 sales of the initial, short-fuselage
DC-9, it became the third best-selling twin-jet after Boeing's 737 and Airbus Industrie's A-320 loved
ones, with a collective two,167 airframes previously being built.
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