McDonnell Douglas MD-90


The McDonnell Douglas MD-90 is a single-aisle airliner developed by McDonnell Douglas from the MD-80, itself derived from the DC-9.
After the more fuel-efficient IAE V2500 high-bypass turbofan was selected, Delta Air Lines became the launch customer on November 14, 1989.
It first flew on February 22, 1993 and the first MD-90 was delivered to Delta in February 1995.
The MD-90 competed with the Airbus A320 and the Boeing 737 NG.
It has a 5 ft longer fuselage to seat 153 passengers in a mixed configuration over up to 2,455 nmi, it kept the MD-88 electronic flight instrument system.
The shorter MD-95 was renamed the Boeing 717 after McDonnell Douglas merged with Boeing in 1997.
Production ended in 2000 after 116 deliveries. Delta Air Lines flew the final commercial flight on June 2, 2020.

Design and development

Background

The Douglas Aircraft Company developed the DC-9 in the 1960s as a short-range companion to their larger DC-8. The DC-9 was an all-new design, using two rear fuselage-mounted turbofan engines, and a T-tail. The DC-9 has a narrow-body fuselage design with a 5-abreast seating with a capacity of 80 to 135 passengers depending on seating arrangement and aircraft version.
The second generation of the DC-9 was originally called the DC-9-80 series or the DC-9 Super 80, but it was later marketed as the MD-80 and entered service in 1980. McDonnell Douglas began studies into shorter derivatives of the MD-80 in 1983, these studies eventually becoming known as the MD-90. For several years, McDonnell Douglas proposed powering the MD-90 with two propfan engines, such as the General Electric GE36 and the Pratt & Whitney/Allison 578-DX. By mid-1989, it was clear that there was insufficient interest in propfan-powered aircraft, so the company reworked its proposals to instead feature the IAE V2500 turbofan, which was estimated to be $1 million cheaper than the GE36 and had already been certificated for the Airbus A320. Within six weeks of eliminating the propfan option, the MD-90 secured a large launch order.

MD-90

The MD-90 was firmly launched on November 14, 1989, when Delta Air Lines placed an order for 50 MD-90s, with options for a further 110 aircraft. The aircraft first flew on February 22, 1993 and the first MD-90 was delivered to Delta in February 1995. The MD-90 was produced adjacent to the Long Beach Airport in Long Beach, California, USA.
MD-90-30 showing a planform view
The MD-90 is a mid-size, medium-range airliner that was developed from the MD-80 series. Resembling the preliminary version of the MD-88 from March 1984, the MD-90 is a, updated version of the base MD-80 with similar electronic flight instrument system and more powerful, quieter and fuel efficient IAE V2500 engines instead of the JT8D engines, which power the MD-80 series. This made the MD-90 the first derivative variant of the DC-9 to use a high-bypass turbofan engine. Due to the heavier engines, the engine pylons feature flaps that deflect 30° downward to assist in pitching down for stall recovery. The system activates automatically when the control column is pushed fully forward.
Typical seating for the MD-90 ranges from 153 to 172 passengers, depending on the cabin configuration and interior layout. The MD-90 was produced in two versions: -30 and -30ER. The -30 has a range of. The -30ER has a higher gross weight and range up to with an extra 565 US gal auxiliary fuel tank. An even longer-range version, the -50, was offered but was never ordered.
The initial MD-90s feature an EFIS cockpit similar to the MD-88's cockpit. The 29 MD-90s delivered to Saudi Arabian Airlines feature a full glass cockpit with avionics and an overhead display panel similar to the MD-11's cockpit for easy transition for the airline's pilots of the MD-11, also operated by the airline.
MD-90-30
No MD-90 orders were received after Boeing and McDonnell Douglas merged in 1997 due to internal competition with Boeing's 737. Delta Air Lines had initially placed a large order for the MD-90 to replace some aging Boeing 727s. After the Boeing-McDonnell Douglas merger, Delta canceled their remaining 19 MD-90 orders in favor of the Boeing 737-800. A total of 40 MD-90s were to be assembled under contract in Shanghai, People's Republic of China under the Trunkliner program, but Boeing's decision to phase out the MD-90 resulted in only two built by Shanghai Aircraft.
MD-90 production at Long Beach, California ended in 2000 with the last airplane being delivered to Saudi Arabian Airlines, and MD-90T production at Shanghai ended in 2000. With 116 MD-90 aircraft produced, the MD-90 production run was the smallest among the DC-9 family. Two aircraft were also produced at Jiangwan Airfield in Shanghai, People's Republic of China.
Following the MD-90 in the DC-9 family was the MD-95, which was renamed the Boeing 717-200 after McDonnell Douglas merged with Boeing in 1997. The main competitors of the MD-90 included the Airbus A320 and the Boeing 737-800.

Variants

;MD-90-10: A shorter variant with the same length as the MD-87, carrying from 114 passengers in a three-class layout to 139 passengers in a high-density configuration. It has a maximum takeoff weight of and a range of with fuel reserves. Engine thrust would be. This variant was not built.
;MD-90-10EC: Unbuilt "European Community" version of the MD-90-10, with a higher MTOW and the engine thrust raised to MD-90-30 levels for an increased range of.
;MD-90-20: Retrofit of MD-80 series aircraft to V2500 engines.
;MD-90-30: Base variant with two V2525-D5 engines and an EFIS cockpit similar to that of the MD-88. This engine also has an option to add 3,000 lbf for use in Hot & High conditions if needed by activating a switch in the flight deck.
;MD-90-30EC: Unbuilt "European Community" version of the MD-90-30, with a higher MTOW and the engine thrust raised to MD-90-40 levels for an increased range of.
;MD-90-30IGW: Increased Gross Weight version, one built.
;MD-90-30ER: Extended Range version of MD-90-30, two built.
;MD-90-30T "Trunkliner": Variant of the MD-90-30 assembled by Shanghai Aviation Industrial Corporation in the People's Republic of China. Production was initially planned to be 40, later reduced to 20, with only two built in the end. To accommodate the heavy aircraft on unsuitable runways, a dual tandem landing gear with more tires to spread the weight of the aircraft was designed for the Trunkliner, but ultimately not used in the two aircraft produced. The Comac ARJ21 is built using tooling retained by the Chinese after the end of the Chinese MD-90-30 program.
;MD-90-30EFD: Enhanced Flight Deck version of MD-90 with the same cockpit as MD-95/B717 and MD-11, 28 built.
;MD-90-40: A proposed variant with a maximum capacity of up to 217 passengers, though the normal three-class layout would hold 170–180 passengers. The derivative would have a storage capacity of, a maximum takeoff weight of, and a height of. Engine thrust would be. This variant was never built.
;MD-90-40EC: Unbuilt "European Community" version of the MD-90-40, with a higher MTOW for an increased range of. Other improvements include wing area enlargement/strengthening, adoption of MD-11 avionics, one-person baggage loading improvements, and better interiors.
;MD-90-50ER:A proposed variant similar to the MD-90-30, but with two extra auxiliary fuel tanks mounted on the belly. The aircraft had an MTOW of, used IAE V2528 engines with thrust, and had an estimated range of.
;MD-90-55: A proposed variant with two extra passenger doors and room for 187 passengers in a single-class configuration.

Operators

was the last remaining operator in 2020. Delta began phasing out its MD-90s in 2017, before retiring its remaining MD-90s after their final flights on June 2, 2020.

Accidents and incidents

As of May 2018, the MD-90 has been involved in three incidents, including one hull-loss accident, with 1 fatality.
;Notable accidents and incidents
  • On August 24, 1999, Uni Air Flight 873, a MD-90, caught fire after a passenger's carry-on luggage containing gasoline was ignited by a motorcycle battery contained in another passenger's carry-on luggage. 27 people were injured with one fatality as a result of the cabin fire. The aircraft was damaged beyond economic repair.

    Specifications