Update – McDonnell Douglas MD-90

Much of the development work, in a conceptual sense at least, has already been done via a continual evolution of the initial MD-81 design. The latest variant, the MD-88, for instance features generally what will ultimately be the baseline MD-90 series flight deck though MDC are also looking at an eventual swing across to an advanced six CRT display similar to that of the MD-11 trijet. In the actual flight development programme the company will test the V2500 nacelle/pylon interface on their developmental MD-80, ironically the same aircraft that undertook most of the UDF test flights through 1987/88. This aircraft will also flight test elements of the new aircraft’s avionics and systems so that by the time the first prototype MD-90-30 becomes airborne in 1993 much of the mechanical problem solving will have been achieved.

This should cut down on the possibility of delays in achieving FAA certification, reduce costs overall and ensure that the first production batches of MD-90s to be delivered to the airlines won’t have to come back to Long Beach at the end of their first year of service to have dozens of small but necessary ADs complied with.

Essentially MDC have launched three primary variants of the MD-90. There is the MD-90-10, which uses the same fuselage as the existing MD-87. The MD-90-30, which is just two seat rows longer than the existing MD-81 family and finally the MD-90-40, a stretch that will accommodate between 170 and 180 pax in a typical two class configuration.

The model to attract sales interest to date, and the first to be developed to certification, is the -30. Also under investigation are special uprated versions of all three, specifically designed for European conditions while a re-engined version of existing. MD-88s is provisionally being designated the MD-90-20.

Incidentally, when the company launched the project they designated the new design the MD90 (as in MD90-30), just to confuse us they have now reverted to their more usual designation style with MD-90 (as in MD-90-30), let’s hope that it doesn’t change again! In greater detail the individual models are:

MD-90-10

The smallest of the family, this model uses the fuselage of the 114 pax MD-87 and like the-87 (and the Boeing 737-500) is really an aircraft optimised for short field operations over long ranges. The MD-87’s hot and high performance is excellent, something that will be improved again in all MD-90 models by the more powerful and fuel efficient IAE V2500s, in this case the V2500-D2 which is derated to just 22,000lb thrust. This will provide excellent long term engine reliability and longevity in addition to a considerable emergency reserve thrust rating and enhanced thrust retention during the climb phase. The -10 will have a typical max payload range with reserves of 2,400nm while later versions may well take this to beyond 3,000nm through additional tankage and uprated engines. The -10 will use the standard MD-80 wing, a new APU and the standard MD-90 series uprated glass (EFIS) cockpit with latest generation Inertial Reference Systems {IRS) and Flight Management System (FMS), etc.

The -10 will have an operating empty weight of 37,000kg (81,500lb) and a gross takeoff weight of 63,100kg (139,000lb). Hough no firm orders for the -10 had been announced at presstIf!1e, the smallest of the family will still be developed in concert with the already ordered -30 for a first flight around late 1993 and a possible entry to service one year later.

MD-90-30

This is the aircraft that will probably be the biggest seller of the three as it equates to what is still the province of the 727-200 replacement market. Active competitors here, apart from the MD-80 itself, are the Airbus A320 and the 737-400. There are still over 800 727-200s in service and as most will need replacing over this decade then this is a market that is not to be overlooked.

Ultimately of course, MDC will inevitably be replacing some of its early build MD-81s and -82s with the MD-90 later in the decade, though it will continue to build and promote the existing MD-80 _ series till the market dictates otherwise. If anything, MDC executives feel that the company’s commitment to the MD-90 will only ensure a greater long term market for the MD-80 as new and existing operators appreciate that the company will be building and supporting this twinjet for many decades to come.

The MD-90-30 is actually two seat rows or 1. 4m (57in) longer than the present MD-88. This slight stretch takes its capacity out to typically 153 In a two class configuration or. 10 pax more than the present aircraft. Range at max pax is 2,400nm with full reserves. Field performance is improved byaround 8% with the 25,000lb thrust V2500-D1s. Operating empty weight is 39,450kg (86,900Ib) while max takeoff weight is 70,760k’g (156,000lb).

MD-90-40

This is the largest of the new twinjets and features a plug fore and aft of the wing for a total stretch of 7. 3m (24ft). Passenger capacity increased 170/180 in a mixed class configuration thus making the -40 a direct competitor to the Airbus Industrie A321 and to a lesser extent the Boeing 757.

The obvious compromise though is in range capability. With the extra metal to lift, the – 40 obviously has shorter legs than its smaller sisters despite the extra power from the 28,000lb thrust V2500-D5s. Max payload range though is still a respectable 1,730nm with reserves. Aerodynamic modelling is still continuing on the -40 and it is likely that it will require a slightly modified wing with upgraded landing gear to accommodate the 74,230kg (163,500Ib) max takeoff weight. First flight of the MD-90-40 is slated for late 1994 with an entry to service by the end of 1995 or about a year after the MD-90-30.

As mentioned earlier, MDC is also studying a special range of options designed specifically for the high density, congested operations that now confront European operators. The European versions would be provisionally designated MD-90-30EC, etc and would feature a revised glass cockpit based on MD-11 technology, increased wing area, significantly increased operating weight, improved interior and revised baggage handling within the hold suitable for one man operation.

Higher rated V2500s would be used on all three variants at the expense of a reduction in fuel efficiency of around 9% overall. MDC is looking for a European partner for this project which might logically also receive sales support from operators outside Europe

grow into a family of jetliners that would still be in production well into the twenty first century.

Total DC-9 sales eventually reached 1,017 whilst orders and options for the MD-80 family now exceed 1,600. Commitments against the MD-90 at presstime totalled 240 comprising 95 firm with 145 on option. That represents a total of well over 2,800. As Douglas currently has over 600 MD-80s on back order, even at an increasing production rate of 14 amonth, it is highly likely that eventual twinjet production deriving from the original DC-9-10 will one day exceed 5,000 airframes. Par ticularly so as the new MD-90 is designed to complement the cheaper MD-80 rather than replace it.

One thing is for sure though, and that is that the latest twinjets from Long Beach will certainly keep the Douglas division of MDC alive and well till well after this writer has been retired.