Update -McDonnell Douglas MD-90

As history records, the definitive MD-90 which made its first flight on February 22 is powered by IAE turbofans. Instead of propelling Douglas back to burly heights, given the transitionary nature of Douglas’ whole airliner manufacturing opera- tion, its importance to the company’s mere survival in this field is paramount.

quieter on takeoff than the Stage III compliant MD-82. This remarkable figure is achieved in no small part by the engines, but other modifications including the lengthened nacelles and an optimal automatic thrust cut back system for takeoff and climbout, contribute. Also, the aircraft’s layout, with the rear mounted engines separated by the fuselage, and wing deflection on rotation and climb also greatly cuts down on noise heard particularly during takeoff and landing.

Because of its low noise properties Douglas expects the MD-90 to be attractive to customers who operate from particularly noise sensitive airports such as John Wayne in Orange County, Los Angeles, who have their own more stringent noise regulations. Douglas is quite confident that the 90 will easily meet any yet to be set Stage IV noise restrictions, something it says will be far more difficult for the 737-400 and to a lesser extent the A320. Furthermore, Douglas claims that noise levels inside the MD-90 cabin are also lower than that of its two direct competitors.

These enticing promises are part of MDC’s strong market- ing push of the MD-90, painting it as a new generation twinjet Today’s MD-90, although extremely different, can be traced airliner, incorporating advanced technologies and methods of back to the original DC-9-10 of more than 30 years ago, and construction, while offering great commonality benefits for more directly to the MD-80 family of the 1980s. More than just current operators of MD-80 aircraft. In fact, despite a number a simple re-engining of a proven and highly successful design, of significant small changes, the MD-90 is designed to be the MD-90 should form the basis of a new generation of 100- certified to the same type rating as the MD-80 (similar to the 170 seat twinjet airliners. This hopefully will provide a solid A320/321 and 737-500/300/400 etc). Other commonality from which Douglas can gain much needed mar- efits include a similar maintenance programme, 60% airframe ket share and achieve its recently stated aim of regaining its and systems commonality, 75% ground support and 100% former position of the second largest airliner manufacturer. ground service equipment commonality between the two Benefiting, as did the 737 and A320, from the massive sales families. So in many ways, the MD-90 is just an extension of growth in the mid to late 80s, the MD-80 alone has reached the MD-80, family, while in others it is a new model line in its sales of over 1000, with combined DC-9, MD-80 and MD-90 own right. sales at more than 2100. Re-engining the MD-80 allows the company to build on its strong and loyal customer base and continue to hold its place before new products come on line. The first version of the MD-90 line to undergo development is the MD-90-30. The MD-90-30 involves replacing the Pratt & Whitney JT8D-200s of the MD-80 with International Aero Engine (IAE) V2525-D5s of 25,000lb thrust. The V2500 is widely regarded as the most technologically advanced engine in its class, now proven in service over the last five years aboard the Airbus A320. In keeping with the MD-90’s ‘environmentally friendly’ marketing campaign, the V2500 is available (as on the A320) with a low NOx emitting combustor.

The V2500 on the MD-90 is the largest engine to be side mounted on a commercial airliner. The increase in weight due to the V2500, nacelles and pylons has resulted in the need to offset the weight by a slight 1. 45mstretch forward of the wing. The stretch increases passenger capacity to a typical two class arrangement for 153 people. Despite the slight increase in weight, the efficiency of the V2500 is such that the aircraft burns approximately 16% less fuel than the MD-82 per seat. In addition, the MD-90 is significantly quieter than the MD-80 series aircraft (the MD-80 was in fact the first stage III jet in its class).

Douglas’ sales efforts are focusing strongly not only on the type’s fuel economy, but also on its low noise and environmental ‘friendliness,’ such as the low noise and low pollutant emissions of the V2500. Pre-empting any official move towards a Stage IV noise regulation, the MD-90 is some 60% Interestingly, the MD-90 participated in the Paris Salon in June, the first time anew US airliner had been displayed at one of the two major European airshows in many years.

As part of Douglas’s dramatic restructuring and over the last few years, the company has adopted a modular construction technique which allows a large reduction in construction time, and the assembly of both the MD-80 and 90 on the same line at Long Beach. The modular construction technique means that the aircraft will be assembled from major subassemblies at Long Beach, rather than almost all construction taking place on site, as was previously the case. In the past the MD-80 fuselage was formed from a clamshell of two horizontal sections, which because of their size could not be made offsite, However, with a change in work methods and practices, the aircraft is assembled from vertical fuselage plugs which to a great degree can be fitted out and wired before mating with other fuselage sections.

Despite the high degree of commonality there are a few important, though by nature minor improvements and modifications to the new type. These include a new, more powerful auxiliary power unit, manufactured by Allied Signal. The Garrett 131-9D is based on that in the Northrop B-2 and is 36% more powerful than the MD-80’s APU, while burning 23% less fuel. The more powerful APU was required because of the greater start up demands of the V2500.

Aneat trick used on the MD-90 uses heated fuel to overcome the wing ice problem of the MD-80. On the latter aircraft cold fuel stored in wing tanks near the upper surface of the wing helped cause surface ice to build up. On the MD-90 heated fuel returns to the main tanks to help alleviate this problem.

Inside the aircraft the cockpit has been based on the electronic flightdeck of the modern MD-88. While not as dependant on a small number of screens as the A320 for example, the MD-90 does feature Honeywell Electronic Flight instruments (EFIS) digital airdata computer and an updated windshear computer. In addition though, reflecting its 1990s lineage, a number of advanced features are installed on the MD-90. Replacing earlier systems employed on the MD-80, the 90 features an advanced Inertial Reference System (IRS) navigation unit, which also provides for the future integration of GPS. Other changes involve the accommodation of an Electronic Engine Control display for the IAE V2500s, which has resulted in some other minor changes. A unique feature of the cockpit will be the Auxiliary Control System which will integrate a number of flight related functions into a single LRU (line replaceable unit).

Moving to the passenger cabin, Douglas has added further refinements and changes over the MD-80 family. Enlarged and lighted passenger overhead bins offer 12% more space over earlier units. Running on both sides of the overhead lockers are unique backlighted full grip handrails which should allow easier movement throughout the cabin for both passenger and cabin crew, negating the need to use the aisle seats to keep balance.

New improved passenger service units include adjustable halogen personal reading lamps, while the flight attendant call button drops down in plain view for cabin staff when activated. Available as an option are inflight entertainment consoles, which will drop down from both sides of every other seat row. Another enhancement allows the removal of the inside and outside windows without having to or cabin panelling.

Of course one of the major selling features of the MD-90 (and indeed the DC-9 and MD-80 before it) is the space efficient five abreast economy seating layout, which has significant passenger appeal. Confirmed by research, and as any frequent flyer will attest, getting stuck in the middle seats between two other passengers (which are invariably two 100kg footballers!) is one of flying’s least pleasant experiences. The five abreast configuration will always have less than half the number of centre seats than on similar six across cabins. In addition, the MD-90 cabin has a wider centre aisle which alternatively can be narrowed to allow a seat width comparable to the wide seats offered by Airbus. Also, passengers in the window seat have more comfort and space. From an operators point of view though, the narrower cabin has some significant economic benefits for premium class over competing wider fuselage aircraft (ie 737 & A320). The fuselage width is ideal for a four abreast business and first class cabin, allowing a far more efficient use of internal space.

No better practical example exists to illustrate this than the premium class configurations of Ansett’s and Australian/ Qantas’ current four abreast layouts in their 737s and A320s. As against a ‘typical’ two class arrangement in the A320 for 150 passengers, because of Ansett’s four abreast premium class, their aircraft have only 135 seats. Meanwhile Australian/ Qantas’ 737-400s have just 127 seats. In stark contrast, when Compass operated its MD-80s (with the same cross section as the MD-90), they were still able to accommodate 142 passen- gers, even though they had 16 first class style seats. It is easy to see who had the most space efficient cabin. In the MD-90 this configuration would equate to 152 seats, significantly in excess of the Boeing 737-400 and A320.

Weighing 70, 760kg at maximum takeoff weight, it is 2887kg heavier than the MD-88. However, endowed with the highly efficient V2500s it has a significantly lower fuel burn and without an increase in fuel capacity, a longer range of 2400mm (4450km) as opposed to 2050nm (3800km). In addition to the type’s low noise emissions, McDonnell Douglas is also quite keen to point out that because of the 25,000lb thrust engines, the MD-90 has a relatively high thrust to weight ratio, and thus better hot and high performance. Douglas sees this as having a particularly strong attraction to South American operators, where the type could offer as much as 30% more payload capability out of high altitude length restricted runways than its competitors. Another benefit of its excellent thrust to weight ratio, and good stability and control characteristics with an inoperative engine is its ability to operate from length restricted runways with greater payloads.

Douglas is promoting all of the MD-90’s performance advantages: long range, high altitude and short field performance and noise sensitive operations combining to offer substantial revenue earning advantages over the life of the aircraft in comparison to its competitors.

As with almost all Douglas products, the MD-90 was intended to become the basis of an extended family ranging from 100 to 170 seats, with the 153 seat MD-90-30 forming the basis and midpoint. At the lower end of the size scale is the MD-95 which will be built by CATIC in China. The MD-95 will be based upon the MD-87 while having considerable commonality with the MD-80 and MD-90, powered by either the Rolls-Royce Tay or Pratt & Whitney JT8D-200 and awaits launching.

More directly based on the MD-90 is the MD-90-50 which will be a higher gross weight version of the MD-90-30, powered by 28,000lb thrust V2528-D5s with an extended range of 2900nm (5374km) which is significantly greater than both the 737-400 and A320. In addition, a subvariant known as the MD-90-55is on offer, featuring a pair of additional doors in the forward fuselage and a maximum passenger load of 203.

Douglas had originally planned to offer two more versions of the MD-90. The first was to be the -10, a shortened version based on the MD-87 and powered by derated V2500-D2 of 22,000lb thrust, has now been overtaken by the MD-95. The second variant, which evidently has not created too much airline interest is the stretched -40 (yes stretched! – at 52. 5m it would be 20m longer than the original DC-9-10 of 1965!) This 74,164kg version would accommodate in the region of 170 to 180 passengers, putting it head to head with the A321 and 757. On top of Long Beach production, McDonnell Douglas was awarded the Chinese Trunkliner contest ahead of Boeing, which will see the establishment of a separate production line. Currently, the Trunkliner covers the licence manufacture by CATIC of20 MD-80s and 20 MD-90-30s (plans for Chinese built MD-90s to feature a specially developed ‘dual tandem landing gear’ have been dropped). Ten MD-80s could be changed to MD-90s, and in the future up to 130 more could be built.

By the time these words are read, the first MD-90 prototype (T-1) will have been in flight test for more than seven months, with T-2, the second aircraft was due to take to the air in September. Douglas has deliberately spaced production of the two types out longer than average, which will allow the incorporation improvements identified in the first aircraft into the second.

The MD-90’s flight test and certification is also 18 months, instead of the usual year, perhaps reflecting Douglas’ desire to avoid unexpected problems which hamstrung the MD-11 certification and development programme. US Federal Aviation Administration certification is planned for August 1994 with entry into service the following October.

Currently Douglas holds firm orders for 77 MD-90s, the launch customer being long time Douglas operator Delta (Delta incidentally was the launch customer for the original DC-9). Additionally, options are held on a further 102 aircraft. MDC’s breakeven point for the MD-90 is just 100 aircraft, which Douglas hopes it will achieve in the next 18 months, and explains why the company is not unduly disturbed by what so far has been slow sales, pointing out also that both the DC-9 and MD-80 were slow sellers initially.

Delta could well become the type’s largest operator, having 150 noisy Stage Two 727s in its fleet which will need replacing (or hushkitting) before the end of the decade, whilst steadily expanding Alaska Airlines (10 MD-90s) could well be in the position to reorder the type in years to come. American Airlines already operates 250 MD-80s, and may find it suitable to replace both 727-200s and earlier build MD-80s The aircraft reportedly is attracting much interest from Asian airlines who are impressed by its low noise qualities, while interest from South American operators centres around its good hot and high performance.

Regardless of whoever orders the MD-90, its success as a programme will be of crucial importance to Douglas as an airliner manufacturer. Douglas has not launched a new programme since the DC-10 in 1970, preferring instead to develop and refine existing designs. Although in some ways justified (sales of the MD-80 are over 1000) this has left Douglas with , given the slow sales of the MD-11. With the MD-12 in limbo after appearing to offer much, the MD-90 might be just what Douglas needs to allow it to place new aircraft into the marketplace and to ultimately regain its status as a major player in the civil market.

No matter, Douglas has a proven track record for producing winning designs, with the MD-90 being in good company. Tackling the firmly entrenched 737-400 and A320 (plus the forthcoming 737-X) in these times of minimal aircraft orders should produce some very hard fought sales battles, with the winner by no means a foregone conclusion. conclusion.