Profile – McDonnell Douglas DC-9

Delta became the first airline to operate the aircraft when it began scheduled services on 8th December 1965. One hundred and thirty-seven Series 1Os were manufactured, and twelve airlines still operate the model. Douglas next examined stretching the Series 10, and in February 1965 Eastern Air Lines placed an order for the new model. This version, originally known as the DC-9B or DC-9 Series 20, had the fuselage lengthened by 9 ft 6 in (2.9m), but before the stetch was effected it was decided to lengthen the Series 10 fuselage by 14 ft 11 in, and this model carried the Series 30 designation. (The Series 20 designation was later used for another version.) The Series 30 had a gross weight of 98,000 lbs (44,440 kg) and was initially powered by JTBD-9 (later, -15) engines of 14,500 lbs (6,580 kg) thrust. The wings were also lengthened, with extended wing tips adding 4 ft (1.21m) to the span, and full-span leading edge slats were incorporated, giving the Series 30 good short-field performance. Up to 115 passengers could be accommodated in the lengthened cabin. The first -30 flew on 1st August 1966, achieved certification in December, and the model entered service with Eastern on 1st February 1967. 611 Series 30s have been manufactured.

Much of the success of the DC-9, when compared to its rival the BAC-111, is due to Douglas’ willingness to customise the design for specific customers. The Series 40 DC-9 was typical of this approach. After conferences with Scandinavian (SAS),the DC-9-40 was developed with a further length increase of 6ft 4in (1.87 m) to seat up to 125 passengers. JTBD-15 engines were fitted, and the gross weight increased to 114,000 lbs (51,800 kg). 1968 saw the introduction of the Series 40 into airline service. Seventy-one of these models were manufactured for SAS and TDA of Japan, and Swissair leased the type for a period from SAS.

The Series 20 designation was readopted for ten SAS DC-9s which were to be operated in hot climates and high altitudes. These 90-passenger aircraft retained the -10 fuselage, utilised -30 wings, and were fitted with the JTBD-9. The first DC-9 -20 flew on 18th September 1968.

The next version of the “9” was the Series 50, an again lengthened model with a length of 133 ft 7 in (40.72 m). Passenger capacity was increased to a maximum of 139, with JTBD-15 or -17 engines of up to 16,000 lbs thrust (7,257 kg) providing the necessary “push”. Minor modifications included an improved Hytrol skid control braking system, changes to the reverse thrust arrangement, revised interior design and lower noise levels. Gross weight had increased to 120,000 lbs (54,400 kg). The wing was virtually identical to that of the Series 30, 40 and 20. Seventy-five -50s have been manufactured, the first of which entered airline service with Swissair in August, 1975.

The DC-9 Super 80 is the latest version of the DC-9. The fuselage has again been stretched by 14 ft (4.2 m) to measure 147 ft 10 in (45,85 m) in length. The wing span has also been increased to 107 ft 10 in (32.86 m), all-up weight increased to 140,000 lbs (63,504 kg), and passenger capacity boosted to 172. The changes, however, are not only dimensional. The benefits of the Super 80 stem from the choice of high-technology JTBD-209 engines of 18,500 lbs (8.391 kg) thrust. These engines, with a higher bypass ratio than the earlier versions, enable Douglas to boast the lowest fuel consumption per passenger mile in any commercial jet. Significant reductions in noise levels make the Super 80 one of the quietest aircraft in commercial service. In developing the Super 80 Douglas flew a Series 50 fitted with JTBD-109 re-fanned engines in January 1975, in an endeavour to develop a quieter engine installation for a proposed retrofit programme. A number of DC-9 variants were experimented upon between 1975 and 1977. One of these aircraft was known as the Series 50RS, with -209 engines and lengthened fuselage. The Series 60 was also conceived in this period, and was to be fitted with CFM-56 or JT1OD engines and stretched fuselage. Other developmental models included a Series 50 with JT8D-17R engines and stretched fuselage, and the DC-9SC, a model with a supercritical wing. The Series 55 evolved from these developments in 1977, fitted with JT8D-207s and a 12 ft 8 in (3.86 m) fuselage extension. The Series 55 was eventually to be scrapped in favour of the Super 80.

The first DC-9-80 made its first flight on 18th October 1979, and the aircraft entered service with Swissair in October 1980. The Super 80 is so named because of the numerous updates and improvements over its forebears. Levels of Equipment have been much improved. A new digital electronics integrated flight guidance and control system has been installed, as has a discrete flap selection System. Structure, engine synchronisation, dual automatic pressurisation system, weather radar and interior design are other areas which have been revamped Added. Perhaps the most dramatic improvement in the Super 80 is the high Technology integrated digital cockpit. New systems lower the workloads in the cockpit, and in spite of the higher all-up weight, the DC-9 Super 80 is certified for two crew operations. Some -80s are fitted with a head-up display for use during take-off, landing, approach and taxiing when visibility is limited. The Super 80 has already attracted orders from at least twelve airlines, and a new model with JT8D-217 engines, named the Series 82, is currently being developed.

In addition to the various passenger configurations, the DC-9 has been used as a freight aircraft. To facilitate this type of operation, Douglas made the DC-9 available with a forward, sideloading freight door. These cargo versions were known as DC-9Cs (convertible), DC-9RCs (rapid change), and DC-9Fs (all freight). The first order for a convertible cargo/passenger DC-9 was made by Continental, and the aircraft, a Series 10, was delivered in March 1966.

The Military DC-9

The DC-9 has found its way into service with the United States Air Force and the United States Navy. C-9A was the designation given to the first version of the DC-9 to enter military service. Known as the Nightingale, the C-&9A began operations with the 375th Aeromedical Airlift Wing of Military Airlift Command in September 1968. The C-9A is specially outfitted as a fully equipped flying hospital ward. Within the United States alone, MAC transports about 6,000 passengers per month by C-9A, usually from military hospitals to medical facilities closer to patients’ homes. Forty ambulatory patients or thirty to forty stretcher patients can be accommodated in relative comfort.

The C-9A is basically a Series 30 DC-9 with an additional 11 ft wide (3.35 m) cargo door and loading ramp to enable easy loading of stretcher patients. Other special features include provision for therapeutic oxygen, a medical suction system, improved lighting, uninterrupted air-conditioning, a special nurses station, and an intensive care compartment. The crew consists of two pilots, two flight nurses, and three medical attendants.

In 1972 the US Navy announced an order for five C-9B fleet logistic support transport aircraft. Like the ‘A’, the C-9B is basically a Series 30, but in convertible cargo/passenger configuration. Named Skytrain II after its extremely successful ancestor, the C-47 (DC-3) Skytrain, the C-9B replaced the Convair C-131 and Douglas C-118 Liftmaster for large aerial movement of freight and passengers. Up to 107 seats can be fitted in the passenger configuration, which are removed and replaced by a roller system in the cargo configuration. Standard cargo pallets can be loaded through a large cargo door in the forward fuselage. In a combination passenger-cargo configuration, three cargo pallets are loaded in the forward fuselage, and up to 45 passengers can be carried in the rear portion.

Australian Operation

As early as 1961, Trans-Australia Airlines and Ansett ANA sighted the original Douglas propositions for a twin-jet airliner. At this stage, two configurations were being evaluated; one with underwing engines, and the other with engines positioned at the tail. Douglas finally settled on the rear-mounted engines for its aircraft. The BAC-111 was also presented to both airlines, but both the British and American propositions were considered to be too small for Australian requirements. The 90-passenger DC-9-10 had, at that stage, an all-up weight of 85,000 lbs. Any aircraft heavier than the arbitrarily chosen figure of 85,000 was, at that time, required to carry a crew of at least three, and the DC-9 had been designed specifically for a crew operation. This regulation was to cause some difficulty when the domestic carriers finally decided to buy a heavier model DC-9.

In early 1965 the DC-9 Series 30 concept was presented to the Australian airlines for consideration. The -30 differed from the earlier -10 in having a lengthened fuselage and a higher all up weight of 100,000 lbs. Other improvements included higher thrust engines, full span leading edge slats, greater passenger capacity and good short-field performance. The Series 30 retained the simplicity in design of its predecessor, an example being the use of actuator tabs for operation of the elevators and ailerons instead of a servo system.

After serious evaluation, Ansett found the Series 30 to be suitable for its needs, provided that a number of custom options were added. These additional features were integral ventral passenger stairs, differently equipped cockpit to lower crew workload, an improved pop-up “shopping list” checklist system, and an auto-thrust system coupled to the integrated flight control system. In spite of the “buy British” policy of the day, both Ansett and TAA, after arguing the benefits of the DC-9-30, obtained permission to acquire the customised type. Orders were placed by both airlines in April 1965.

Both airlines then sent evaluation and preparation teams to the United States in 1966 to begin the long and arduous task of preparing for the type’s entry into Australian service. In February 1967, the first group of fourteen Ansett pilots arrived at Douglas’ Long Beach establishment to commence their conversion course. Douglas Aircraft had occasion to pronounce the Ansett crews to be the best-prepared group of pilots to arrive in such circumstances.

On 6th March 1967, the first customised production DC-9 Series 30, Ansett’s VH- CZA, made its first flight from Long Beach airport under the control of Captain Dusty Lane. TAA received its first aircraft, VH- TJJ, shortly afterwards. Ansett decided to keep CZA in America until crew training had been completed, and it was Ansett’s second aircraft, CZB, which was the first to arrive in Australia. Both TAA and Ansett fitted their aircraft with two rubber bag fuel tanks for the ferry flight to Australia. The tanks, each holding 1,000 US gallons, were installed and connected to the cross-feed system. Commencing from Long Beach, California, the ferry flight took the aircraft through Honolulu, Pago Pago, New Caledonia, and finally to Essendon. Ansett’s CZB was piloted by Captain Lane, and TAA’s TJJ by Captain Don Winch. Both aircraft arrived in April 1967, and, in the true two-airline spirit, both commenced regular services on the same day – 17th April 1967.

The Department of Civil Aviation was still showing opposition to the two-crew operation of the DC-9-30, and for a period before it was finally agreed that two-crew operation could be successfully applied, the Australian DC-9s carried a flight engineer as a third crew member, seated in the jump seat between and behind the two pilots.

The last TAA DC-9, VH-TJU, was delivered in October 1971, with Ansett’s last, VH-CZL, delivered the following month. DC-9s have been used on numerous Australian legs, the longest of which is the Adelaide to Perth run, during which it is sometimes necessary to land at Kalgoor- lie for fuel. The shortest leg flown is the Hobart to Launceston hop, a flight that averages twelve minutes. The aircraft has a four-hour endurance with reserves and has a very quick turnaround time of fifteen to thirty minutes. Australia’s twenty-four DC-9s have operated without significant incidents. There have, naturally enough, been some minor incidents such as single-engine failures, bird strikes, foreign object damage, and lightning strikes. In 1970 a DC-9 left the flooded runway at Brisbane after landing with a heavy crosswind. Fortunately, there were no injuries. However, this good safety record is indicative of the high standards of professionalism in the maintenance and operation of the aircraft, and additionally must shine favourably on the integrity of the DC-9 itself.

In 1980, Ansett announced the decision to acquire Boeing 737-200, 767, and additional long-range 727-200 aircraft while phasing out the DC-9. The decision to retire the DC-9 has ended a long association between Ansett and Douglas, and the Ansett crews are naturally sorry to see the DC-9 go, but also happy to see the introduction of the new aircraft. TAA, on the other hand, have opted to stay with the DC-9 for some time yet, and in November will begin a modernisation programme to refurbish the DC-9 fleet. A new system of engine system synchronisation and an improved dual electronic cabin pressurisation system will be installed to improve passenger comfort. Interiors will be re- vampled with new seats, new decor, and fully enclosed overhead stowage lockers. The new seats will provide more legroom and will weigh significantly less. Moder- nising of the TAA Series 30s will be expected after delivery of the new Airbus. It is likely that TAA’s DC-9s will eventually be replaced by the proposed Airbus A320 aircraft if it goes into production. The DC-9 has earned the respect of its passengers and operators, has proven to be a very successful sales winner, and has shown itself to be a pilot’s delight.