Drukair flights to three domestic airports have been temporarily suspended following the grounding of the aircraft, ATR42-500 since December 29.

According to airline officials, a technical glitch in one of the engines has grounded the aircraft. An inspection of the aircraft is currently underway after the inter turbine temperature (ITT) in one of the engines was found to be higher than the other engine.

Officials said that the temperature however, was within the limit. But in case of an engine failure, the other engine needs to provide the required boost so there is a chance that the ITT may cross the limit, officials said.

Drukair CEO, Tandi Wangchuk, said the issue is mainly concerning the MCT RTO (Max continuous Thrust at Reserved Take-Off) in one of the engines in case of failure of the other engine.

“From the engineering perspective, the parameters are within limit and the aircraft, in particular the engine is serviceable and airworthy,” he said. “However, keeping the difficult terrain in mind, the pilots are not comfortable and do not wish to take a chance.”

Tandi Wangchuk said that in order to address the concerns of the pilots on MCT RTO, Drukair engineers are carrying out a comprehensive inspection. A borescope (visual inspection of aircraft engines where the area to be inspected is inaccessible by other means) inspection of engine number two has been organised.

An inspection by engineers from Airworks, an aviation service provider, was carried out yesterday. “We are also replacing suspected components which could hamper the engine’s performance,” said Tandi Wangchuk. The final part of the engine will arrive today, after which a proving flight will be held to allay the concerns, he added.

Provided the result from the borescope inspection is within limit, the cost of the recovery is expected to be less than USD 20,000.

If things work out as planned, the aircraft is expected to resume service by January 4. “That is if the findings from the inspection are within limit and pilots are happy with the result from the proving flight,” said Tandi Wangchuk. “In the worst case scenario, it will be grounded until January 21 when a spare engine is sourced for change. This is if the findings from the inspection are out of limit and the aircraft is no longer allowed to fly before changing the engine.”

Meanwhile, international flights where the ATR flew are being substituted with an airbus. Also commuters wishing to cancel their domestic bookings are being refunded entirely.

The aircraft is about 14-and-half-years old.

Younten Tshedup| Trashigang