Swiss Jet Ltd, which started commercial operations with its first A119 Koala in the southeastern part of the Swiss Alps at the beginning of 2008, feels the retrofit of a bubble door could add value to its operations. The company, which added a second A119 in mid-2008, a MkII, says the introduction of a more flexible Agusta flight and maintenance schedule has proved positive for business.

Renata Laitenberger, head of business development and marketing, says: "Both Koalas are used for a wide range of different assignments in Switzerland, including aerial work, passenger flights, filming and heliskiing."

She adds: "The sheer scope of operations has necessitated the addition of various parameters to the maintenance schedule. This has made planning relatively complex, of course, because as pure operators we do not have our own in-house service and maintenance facilities. At the moment, we have no exact data as to the vehicle's reliability or how the Pratt & Whitney engine will behave over time with so many different assignments, landings and transport rotations.

"So far, we have had no significant ground time as a direct result of the engine. One thing is for sure, however: the engine's first shop visit will be due to the cycle limit on the compressor turbine disk.

"According to the P&WC mainten-ance manual, the number of cycles for a new engine carrying out mixed operations with aerial work can be significantly restricted, although this does not affect the TBO. Otherwise, the engine has proved itself to be extremely reliable in everyday use."

It is, Laitenberger says, a similar story with the airframe. "Since Swiss Jet Ltd has no maintenance facilities of its own, we use the extended inspection program offered by Agusta SpA. Until recently, maintenance was due after 25 flying hours or every 30 days. Agusta has now increased this interval to 50 hours or 60 days. This has made us more flexible and improved both flight and maintenance scheduling."

Laitenberger points out that Swiss Jet is very much dependent on suitable maintenance working packages. "In the case of the Koala, this is not always straightforward because various task groups with various tolerances - or in some cases with no tolerances whatsoever - have to be considered. These include extended inspections, special inspections, CMRs, discard time limits, servicing and overhauls."

She observes: "One rather unusual aspect of all this for us, as a helicopter operator, is the fact that maintenance intervals are so closely tied to the number of landings completed. Specific maintenance jobs have to be carried out on the fixed landing gear every 300 and 1,200 landings. As soon as we carry out aerial work, multiple landings are the order of the day and we have to keep a close watch on the number completed."

Laitenberger says the supply of spare parts for Swiss Jet's Koalas from Agusta has been very good thanks largely to excellent relations between the manufacturer and maintenance contractor Karen SA in Lodrino. "So far, they have always been able to offer us a solution at short notice in the form of standard exchanges or loan units. Looking to the future, we would very much like to retrofit our helicopters with a certified bubble door. The weather can get bitterly cold in the Engadin in winter and the shoulder seasons, and a bubble door would allow us to carry out long-line operations with the pilot's door closed. There is one bubble door, certified in Canada, that can be inserted in the original door but this, unfortunately, does not yet have EASA approval."

Manufacturer's comment

Having announced the AW119Ke or "Koala enhanced" in 2007, AgustaWestland started customer deliveries of this version last year. The AW119Ke offers a number of improvements over the A119 Koala due to its increased take-off weight giving greater payload and new main rotor blades which further enhance the performance of the aircraft. Existing owners of A119 Koala aircraft can retrofit the changes to benefit from the improvements delivered by the AW119Ke.

AgustaWestland is also expanding its network of service centres both in and outside Europe to deliver spares, maintenance, support and training closer to its customers.