MD-xx question

[aviategw]

This is probably a broad question, but what is the difference between an MD-80, MD-82, MD-88, MD-90, etc? They all kinda look like DC-9s, just a little bit longer, sometimes with a flattened tail cone, sometimes with turbofan looking engines, sometimes with turbojet looking engines.


Sorry for the broad question, but I've always wanted to know....

[Cheechako]

I was boarding an MD-80 somewhere, I can't even remember which airline, Alaska I think. The aircraft data plate is right there in the doorway. I looked at it and it said TYPE: DC-9-83. I think the whole MD-8x family is under the DC-9 type certificate. Just the variants, 83, 87, 88, etc are different. Don't know about the MD-90, though. I think the Boeing 717 was supposed to be the MD-92. . .

I still haven't figured out which of them have the tail cone or the fin "flattened tail" as you said. My guess is that the fin is on the later models, like the MD-90.

[Joe]

The AIRLINERS.NET Aircraft Data and History pages describe the different types pretty well:
Douglas DC-9-10/20/30
Douglas DC-9-40/50
McDonnell Douglas MD-81/82/83/88
McDonnell Douglas MD-87
McDonnell Douglas MD-90
Boeing 717
Basically, the DC-9, MD-80, MD-90, and B-717 are all part of the same family of aircraft.
DC-9-10: Original 70-seat DC-9, entered service 1965.
DC-9-30: Almost 15 ft. longer, with 105 seats, entered service 1967.
DC-9-20: -10's fuselage with the -30's more powerful engines and longer wingspan.
DC-9-15: A -10 with more fuel and higher weights.
DC-9-40: Over 6 ft. longer than the -30 and more powerful engine options, seating 125, entered service in '68.
DC-9-50: The largest DC-9, a further 8 ft. longer than the -40 with 139 seats, as well as a new cabin interior. Entered service in 1975.
The DC-9-80 was renamed MD-80 in 1983, and is a generic designation for the whole series. It is a stretched and improved devolopment of the DC-9.
MD-81: First customer delivery in 1980.
MD-82: More powerful engines.
MD-83: Extended range with extra fuel and more efficient engines.
MD-88: MD-83's engines with and EFIS (Electronic Flight Instrument System) and a new cabin interior. First flight in 1987.
MD-87: Over 17 feet shorter than the rest of the series, similar in length to the DC-9-30. Also featured an EFIS, and options including a HUD, and more efficient engines. It also features improvements to the late-production -80s, such as the newer tailcone. First flight in 1986.
MD-90-30: Longest aircraft in the entire family. 4.5 ft. stretch to fit 10 more seats, newer IAE V2500 turbofans, the EFIS flightdeck of the -88.
B-717: Originally designated as the MD-95 before the MDC/Boeing merger in 1997, Boeing relaunched it as the 717-200 in early '98 (The "717" was originally allocated to the military C-135/KC-135 family). Fuselage is 4¾ ft. longer than the DC-9-30, and uses the DC-9-34's wing. Also has a 6-LCD EFIS flightdeck, and a cabin interior similar to the MD-90. A shortened -100 and a stretched -300 have been studied.

[roundout]

this is purely from way old memories, probably fairly vague, and probably contains inaccuracies. that said:

MD-81 is a stretched DC-9 with updated engines
MD-82 has the low-drag tailfin and higher thrust engines
MD-83 has extended range
MD-87 is a shortened-fuselage, longer-range with different engines (also had low-drag features which other variants lacked)
MD-88 is an MD-83 with glass cockpit
MD-90 has a stretched fuselage ahead of the wing and the extremely large engines in the back. also has glass cockpit.

Doug Taylor is probably the best person to ask about this....hth

[doug_or]

The MD-87, MD-90, and 717 all share the extended tailfin (if you check pics on airliners.net you can the see fin appears to go past the stab fairing in the back). I wasn't aware of any other differences on the vertical stab between sub variants.

I believe the tailcones are actauly replaceable. Some airlines have chosen to replace the older DC-9 style cones for so called "screwdriver" tails to reduce drag and fuelburn. I'm pretty sure the screwdriver tail were standard equip. before the introduction of he MD-87.

All DC-9 and MD-8X aircraft use the JT8D turbofan. I think the older ones use the same types as the 727 (-7 through--17?), while the MD-80s use versions of the higher bypass -217 models.

edit: learned to type