Update – Airbus A321

Airbus Industrie, after a shaky start during the 1970s has become a well documented success, perhaps best illustrated by the delivery earlier this year of their 1000th aircraft (an Air France A340). This fact is particularly impressive considering that their 500th aircraft was only delivered in 1989. Spearheading this massive surge in sales has been the 150 seat A320, with 710 firm sales since its launch in 1984.

Entering service in 1988, the A320 was something of a mini revolution in its class, being the first airliner to introduce fly-by-wire (discounting Concorde), and sidestick controllers in place of conventional yokes, in addition to extensive use of composites and of course the much publicised electronic cockpit. Thus both its sales success and high levels of advanced technology makes the A321 stretch a logical develop- ment. It allows Airbus to both fill a market gap and further broaden the A320 family’s market appeal because of the significant commonality benefits.

The go ahead for the A321 was announced in March 1989, with the formal launch occurring in November that year. Roll out took place on March 3 this year, with the first flight on March 11. A nine month test flight and certification programme should see JAA certification awarded by years end, with first deliveries to Lufthansa of V2500 powered aircraft due for January 1994, while first deliveries of the CFM powered version to Alitalia are scheduled for the following March.

Since its launch the A321 has achieved firm sales of 153 aircraft, including ten orders from Ansett Australia. For 180 seat class aircraft, Airbus predicts a market for 1500 units over the next 15 years.

From the beginning the A321 has been designed as a minimum change stretch of the A320. To this end it is almost identical to its smaller stablemate in every respect except for weights, and of course length. As an A320 derivative, it features an identical glass cockpit with the now familiar sidestick controllers and fly-by-wire flight controls.

There have however been a number of important, though minor modifications in order to maintain the A320’s performance over all areas of the envelope. The wing, while essentially identical to the A320’s, features a new double slotted flap arrangement which was needed to retain the A320’s takeoff and landing performance due to the increased weight involved. In addition, the wing’s camber and trailing edge chord were both slightly increased to keep the A321’s cruise performance in line with that of the A320, again due to the aircraft’s higher weight.

Other modifications to deal with the increased length and weight involved strengthening the main and nose wheel under- carriage units, increasing the tyre size for better braking, minor changes to the oxygen system, simplification of the fuel sys- tem, (which involved a weight saving of 40kg) and modifica- tion to the flight control system to deal with the type’s different handling properties.

The most obvious change though is of course the 6. 93m fuselage extension which yields a 24% increase in seating capacity, from 150 to a typical arrangement for 186, and a 40% increase in underfloor volume. In addition to the wing modifications mentioned above, the increased fuselage length and aircraft weight has necessitated some strengthening of the fuselage centre section.

The 13 frame stretch involves two firsts for Airbus. Italian manufacturer Alenia has joined the consortium as a risk sharing partner on the A321 programme, and is responsible for the forward wing stretch plug. The 4. 26m plug is constructed at Alenia’s Naples facility. For the first time also, British Aerospace is involved in construction of the airframe, (BAe of course is responsible for wing design and manufacture for all Airbus products). In addition to its usual 20% share in the programme, BAe is responsible for construction of the 2. 67m rear fuselage plug, which it builds at its Filton plant.

Another first with the A321 programme is the involvement of a Japanese company, Kawasaki Heavy Industries, who produces fuselage panels under subcontract to BAe.

The longer length of the fuselage also made necessary the relocation of emergency exit doors. Compared to the A320, which also has eight exits, the A321’s emergency doors have been enlarged and repositioned for and aft of the wing.

Another important change is of course the uprated engines, with both IAE and CFM offering more powerful derivatives of the powerplants already aboard the A320. International Aero Engines (IAE), a five company consortium, has developed the V2500-A5 for the A321, which has a thrust rating of 30,000lb, up 20% on the base version powering the A320. This thrust increase was developed by producing a larger core. In addi- tion, the V2500-A5 is fully interchangeable across the A320/ 321/319 family giving complete commonality, the only difference between engines of different thrust ratings being the control data plug.

CFM International meanwhile has two derivatives of its popular CFM56 on offer. The standard A321 version, the CFM56-5B, also uprated to 30,000lb, and the optional CFM 56-5B2 of 31,000lb thrust.

Both IAE and CFM engines have the option of ‘environmentally friendly low NOx emitting combustors, in line with current trends towards more ecologically sound designs.

The stretch has given the A321 a maximum takeoff weight of 83,000kg, an increase of 13% on the A320-200. With the dramatic increase in hold volume, the A321 can now uplift a maximum payload of 22,000kg. Ten modified LD3 containers (which of course are completely interchangeable with the A320) can be stored under the floor.

Typical seating arrangements for the A321 would be 16 first class and 170 economy class passengers, or a one class arrangement for 200 economy class seats. A high density 29in pitch arrangement for 220 passengers could also be used.

The A321 performance includes a range of 2350nm (4355km) with a full passenger load and their baggage, but without any hold cargo. Because the 321 is a minimum change derivative of the A320 it has suffered a decrease in range as the fuel volume was not increased. With a five tonne underfloor payload and 186 passengers, the A321’s range is 1450nm (2690km) with reserves. Maximum fuel for both the A320 and A321 is just over 19,000kg. By way of comparison the A320 has a maximum range with 150 passengers of 2930nm (5430km).

The most obvious competitor to the A321 is Boeing’s 757. The 757 has now been available for over a decade and has become very successful for that company, with more than 800 sold since first orders were placed.

From the start though it should be appreciated that the 757 is a bigger aircraft than the A321, in fact it is about 10,000kg heavier at max takeoff weight. A typical two class passenger configuration for the A321 seats 186, while the 757 commonly accommodates upwards of 202 (typical two class arrangements vary between 178 and 208 passengers). Furthermore, the 757’s range is better by almost 600nm (1600km), or for the long range higher weight 757 even more.

Having said this though, Airbus is keen to point out that the A321 has lower direct operating costs per seat than the 757. Airbus has stated that the A321 burns about 20% fuel less than the 757. This is not surprising as the 757’s engines produce approximately 9000lb thrust each more than those on the A321, as they have to carry a heavier load. In relative terms though, the A321 comes out ahead particularly in the area of fuel burn per seat.

More than being less expensive to operate than the 757, there is one other very strong drawcard offered by the A321, and that is its almost complete commonality with the A320. Anumber of synergies exist between the operation of two very similar types within an airline fleet, particularly in the areas of airframe and engine maintenance, crew training interoperability, and so on. Airbus has predicted approximate savings of $US800,000 per year per additional aircraft of the A320 family operated (as opposed to buying and operating a completely different type). Up front savings have been identified in the areas of engine spares, airframe spares, and simulator economies, while ongo- ing savings come from maintenance, flight and aircrew training and aircrew productivity.

Simulator and aircrew training savings occur because the A320 and A321 share a common type rating, which means that from a pilot training point of view, both types are almost identical, and there is no need for any transition training between the two types. This means that in effect, all current A320 pilots are also rated on the A321. Airbus invested a great amount of energy into this area so that the handling qualities of the two types were close to identical. This results in there no longer being the need to have separately trained pools of pilots for different aircraft. These commonality savings are similar to that experienced by operators of the current generation of Boeing 737s (ie the -300, -400 and-500), between the A300-600 and A310; and the Boeing 757 and 767.

Furthermore, in addition to the savings within the A320 family, there are also substantial crew training savings if an airline also operates Airbus A330s or A340s, which also share a common cockpit with the A320/321.

Airbus’ Cross Crew Qualification (CCQ) programme means that the time (and hence money) spent on transition courses is dramatically reduced. For example, the recently validated Aeroformation CCQ transition course from the A320 to the A340 takes just 14 working days compared with the standard 30 working days. (Aeroformation, Airbus’ fully owned training arm is also preparing for FAA and JAA validation of further CCQ aircraft combinations within the Airbus family such as A340 to A320 and A340 to A330 etc). CCQ also allows mixed fleet flying of any of the A320/321/330/340 aircraft families, adding significant savings from aircrew productivity.

As mentioned, the first flight of the A321 in March this year marked the beginning of a nine month test flight programme. Progressing smoothly at the time of writing, the type’s initial handling qualities have been assessed during approximately 70 flight test hours involving the first prototype. Of particular interest is that the new double slotted flaps are giving the expected CLMAX (performance) in the landing configuration; while there are expected to be no Cross Crew Qualification problems for A320 pilots.

Four aircraft will eventually be involved in the flight test campaign, two powered by IAE engines, and two powered by CFMs. The second A321 was due to take to the air during May, the third in July and the fourth in September. All aircraft will eventually be brought up to airline standard and delivered to customers on the completion of the flight test programme.

Before flight testing had begun firm orders for 153 A321s had been placed with the manufacturer. With the exception of Ansett and Kuwait Airways, all orders have been placed by European operators (Alitalia alone has firm orders for 40). The design is yet to attract sales from the all important North American market where the 757 has enjoyed much popularity, although the success of the A320, with orders from Northwest, United, America West and Air Canada, in the region does indicate that the type should achieve a high degree of market penetration in the coming years.

When Lufthansa takes delivery of its first A321 in January next year it will be perhaps the most visible proof yet that the Airbus A320 product line has come of age. The expanded family can only serve to further ensure the attractiveness of the A319/320/321 line, ensuring that Airbus Industrie’s most successful aircraft programme remains as such for some time to come.