Update – Casa/lPTN CN-235

Indonesia of course makes no secret of how it wishes to build a major regional aerospace manufacturing industry before the end of this century. It has already gone a long way towards achieving this goal and its fruitful partnership with Spain’s CASA (one of the world’s oldest aircraft manufacturers) has resulted in the development of a most interesting regional airliner in the CN-235.

The initial motivation for the development of the CN-235 grew from the introduction of deregulation in the US and the coincidental rewriting of FAA regional airliner design requirements which allowed a new generation of aircraft to be developed which particularly suited the 30-44 seat category. What seemed a good idea at the time though, ultimately grew into the hardest-fought market segment in commercial aviation with nowadays some 13 new generation aircraft competing for regional airline orders against more than a thousand existing quality second-hand aircraft in the same category. Despite this, the CN-235 has sold very well via its captive market base in Spain and Indonesia and at time of writing had firm orders logged on more than 113 aircraft.

Following on from the initial definition studies of 1980, CASA approached IPTN (ex Nurtanio) to investigate their teaming to jointly develop an aircraft about double the size of the existing C-212 Aviocar commuter/utility aircraft which Indonesia was also building under licence as the NC-212.

The collaboration was formally approved by both parties and a new company, Airtech, was formed to develop, build and market the new 40-44 seat airliner. Development on the project though was not hurried as there was much to do even outside normal aircraft development. A completely new multi-million dollar manufacturing facility had to be built by IPTN at Bandung, Indonesia while CASA themselves forged ahead with enhanced versions of their existing C-212 and C-101 projects in addition to the -235.

Utilising more than a decade and a half of practical operational experience gained through Aviocar, the Airtech design team began to develop a regional airliner that would be just a little different from most of its immediate competitors. Firstly, as roughly half of the planned production would be destined for the military, a rear loading ramp was incorporated as standard equipment. This also allows faster loading/unloading of baggage in the passenger role and speeds turnarounds tremendously as a specially designed container, affixed to the ramp, is conveniently accessible at waist height by airport staff.

Another requirement was for a wide body style cabin with comfortable four-abreast seating. Airtech figured that this would generally provide greater passenger appeal in addition to offering a larger and more capable cargo capability. In the latter role the CN-235 can uplift 4 LD-3 containers weighing up to 5 tonnes. Furthermore, in the freight role, the rear ramp and optional roller floor greatly assists in loading/unloading in addition to providing the ability to carry unusual outsize loads unable to fit through a standard side freight door.

The third consideration was the use of fuel-frugal General Electric CT? turboprops. Through the entire development period these fortunately did not meet with some of the unusual, and now fully rectified, problems that the Saab SF340 had with essentially the same powerplants. Their 1772shp enable the -235 a maximum cruise speed of around 250kts while having the capability to operate four 100nm sectors at max passenger load without refuelling. In the busy third-level scene this further speeds turnarounds and enables greater productivity from the aircraft over the course of a day. Another consideration was a slightly reduced pressure ratio for the onboard pressurisation. This allowed a simplified and lighter airframe pressure structure and results in lower pressurisation maintenance costs over a period of time. Airtech logically point out that an aircraft operating in the regional airline scene is not needing to climb to very high altitudes and thus spends most of its life below 12,000ft where a cabin pressure equivalent to five or six thousand feet is totally acceptable to even the most sensitive passenger.

Airtech itself is a straight 50/50 partnership between CASA and IPTN. The fruits of their engineering efforts were ultimately rewarded through the middle of last year when full Spanish, Indonesian and European JAR certification was awarded to the CN-235. The final endorsement of the new airliner though came in December when the FAA awarded certification to the aircraft to full FAR 25 and FAR 121 standards after a mere 38 hours of flight test. Deliveries to Merpati, a very large Indonesian domestic, and Aviaco, based in the Canary Islands, commenced earlier this year as combined production begins to gear up towards a target of four aircraft monthly from the joint facilities.

Component production is split equally between the two partners so that no company actually produces the same hardware. CASA for instance produces the inner wing sections, forward fuselage, centre wing and engine nacelles while IPTN produce the wing outer sections, rear fuselage and tail unit. The GE engines, Rockwell Collins avionics and Hamilton Standard propellers all come direct from the US anti provide a considerable US involvement in the value of each aircraft sold. All US, Europe and Australian-bound aircraft would be assembled though by CASA at Seville, Spain.

With Merpati the -235 will replace F27s and HS748s, with Aviaco, which is a subsidiary of Iberia, it will replace F27s and augment that carrier’s DC-9s on many shorter routes.

Ideally the CN-235 needs to be compared more to the ATR42 in terms of size. Passenger capacity is up to 44 with a 30in pitch arrangement or 40 at a more acceptable 32in pitch with standard galley provisions. This then places the aircraft marginally above the competing Saab SF340 and DHC Dash 8 though in Australia the 36-passenger rule (per flight attendant) tends to make this a rather academic benefit. Airtech are also eyeing the possibility of a stretched 60 seater though this variant most certainly won’t be launched till the partners see a considerable livening up in this fairly dormant sector of the market.

The future of the Spanish/Indonesian CN-235 certainly seems assured. The partners wisely selected a niche of the market that had been largely left untouched by their many competitors. They then effectively split the development costs by forming a joint partnership and finally assured the aircraft’s immediate success by gaining a large number of home orders for the type even before rollout. It was of course not missed by either party that this had been precisely the same course (minus the partnership) taken by Brazil’s Embraer two decades earlier in launching the successful Bandeirante.

There is indeed a lesson here for Australia, if only we could see it!