Over half of South Korea's fleet of Boeing CH-47D Chinook transport helicopters have been grounded for more than a month because of problems with a batch of combining transmissions (also referred to as c-boxes) and a dispute with the US Army.
The South Korean army first discovered faults with several Chinook c-boxes in June, following their delivery after completing an overhaul at a US Army facility in Texas. The fleet's readiness subsequently dropped as 16 of 28 aircraft were gradually removed from service.
As of late last month, all 16 aircraft remained out of service. Ten of these were grounded because of a c-box shortage - 12 faulty boxes were in the USA for repair.
Another six helicopters remained in South Korea, which carries only eight spare c-boxes. The other six aircraft were grounded administratively pending the results of an analysis conducted on two of the faulty c-boxes.
Industry sources say that the latter six aircraft could be returned to service from late August and that the US Army is attempting to convince its South Korean counterpart that the grounding order for the Chinooks is unnecessary.
The US Army has discovered the same problem with a batch of its own c-boxes, but has decided the issue does not merit the grounding of any of its aircraft.
Sources say Seoul and Washington are also squabbling over who should pay for the cost of repairing the faulty gear boxes.
Source: Flight International
