Andrzej Jeziorski/MUNICH

DEUTSCHE BA HAS suspended further Saab 2000 deliveries to its fleet, after both it and Swiss carrier Crossair were hit by poor dispatch reliability during the harsh European winter.

The main problems were brake icing and the ingestion of de-icing fluid by the auxiliary power unit (APU), causing smoke in the cabin. The aircraft has also suffered nuisance cockpit warnings, which have caused flights to be delayed.

Crossair, which operates 18 of the slow-selling 50-seat turboprops, says that it has restored dispatch reliability to about 99% now, from a winter low close to 98%. Deutsche BA, which has a smaller fleet of five aircraft, was harder hit.

While declining to give details, Deutsche BA managing director Richard Heideker confirms the aircraft's reliability has been "unsatisfactory" in recent months.

As a result, the company has shelved plans to take two more aircraft in the third quarter of this year until Saab comes up with adequate improvements to the aircraft.

In an earlier attempt to solve the brake icing problems, Saab fitted new water shields to the undercarriage, which exacerbated the problem. Crossair avoided the worst of the troubles by returning to the old shield and improving its ventilation, but Deutsche BA attempted to use the modified shields and suffered as a result.

According to Saab operations chief Johan Oster, the company still has no solution to this.

The APU de-icing fluid ingestion problem initially led to the unit having to remain switched off while the aircraft was being de-iced. Saab says that this problem has now been solved by the addition of a spoiler at the intake of the APU.

Crossair says that it has also found that pilots were frequently receiving nuisance status messages from propeller over-speed sensors. Oster says that the problem will be solved by software improvements this year.

The Swedish manufacturer has still not met guaranteed internal cabin noise levels of 76dB. Saab is to issue operators with a new improvement kit to the active noise-control system which will bring noise levels down to 78dB, and Oster says that tests carried out at Saab of further noise reduction measures have yielded "encouraging" results.

Source: Flight International