Nykoping-based CTT Systems gained a huge boost last month, when Air New Zealand ordered 42 units of its Zonal Drying System, intended to eliminate condensation inside aircraft. The units will be deployed across 13 Airbus A320s, five Boeing 767s, 16 737s and eight 777s. Installations will begin next month.

CTT was founded in 1991, to market technology acquired from industrial air treatment company Munters. In 1996 it sold its first ZDS, for which it holds a worldwide patent, to Martinair. It has since won orders from Air Berlin, Air Mauritius, Continental Airlines, Lufthansa and TAP, among others.

In the past few years, CTT's marketing campaign has been focused on the system's environmental benefits. It is claimed that ZDS can deliver a weight saving of 200-300kg (440-660lb) on a 737-sized aircraft, by means of preventing water build-up in the crown area, sidewalls and belly. The message appears to be getting through. In announcing its CTT order, Air New Zealand cited its aim "to reduce fuel burn and consequent emissions" by lowering weight.

On top of its retrofit business, CTT has gained potentially lucrative footholds in new programmes. Indeed, employee numbers at CTT have roughly doubled, to 40, in the three years since 2005 Boeing selected the ZDS as standard equipment for the 787. The system is also offered as a buyer furnished equipment option on Next Generation 737s.

Meanwhile, CTT's humidity control system, branded Cair, has found favour with Airbus, which has selected it as an option for the crew rest areas on the A380. Airbus has also signed a letter of intent to include the Cair system in the A350 XWB programme.

Yet it has not all been plain sailing for CTT. In May 2006 the European Aviation Safety Agency issued an airworthiness directive that noted that "a Zonal Dryer P/N 3000-002, installed in Boeing 747-400 aircraft, shows sign of premature material failure" and instructed that other Zonal Dryers of similar design "must be switched off". The affected part numbers were deployed in roughly 30-40% of the systems then in operation, in CTT's estimation.

However, in August that directive was superseded by another AD, which stated: "Investigation showed that such failure was caused by combustion of contaminants in the dryer unit. This Revision 1 is issued following the development of a new dryer unit which removes this combustion risk. The installation of the new dryer unit is now approved... The Zonal Drying System can be reactivated." Work is under way to modify those dryers deactivated by the 2006 AD.

CTT's journey toward recouping its initial investment was slowed by the 2006 AD. Delays to the 787 also had a negative impact. However, in February CTT partnered sales agent Satair in a bid to plug gaps with retrofit business. To judge from Air New Zealand's endorsement, the partnership is bearing fruit.

Source: Flight International