By Venkatchari Jagannathan Chennai, May 8 : With 50 per cent of its fleet grounded due to the problems with Pratt & Whitney engines, the Wadia group's low cost Go Airlines (India) got a portion of its aircraft hull insurance premium from its insurers, said a top official. The airlines' total fleet size is 54 aircraft, out of which 27 have been grounded for more than a year, Kaushik Khona, Chief Executive Officer, Go Airlines, told IANS. "Last year, we got a refund of the premium paid for covering the aircraft hull. The refund was about 70 per cent. The insurer was New India Assurance," Khona told IANS. However, he declined to share the actual quantum of 'lay-up period' premium refund received by Go Airlines. Simply put, lay-up premium refund in the case of aviation insurance means refund of premium for the period an aircraft did not fly. When this refund would kick-in is a subject matter of the policy conditions. Even though the aircraft is on the ground, the airline will not get a premium refund on a pro-rata basis as it is exposed to various kinds of risks while on the ground. Normally, the lay-up premium refund is adjusted at the end of the policy period. In normal circumstances, an airline may have a couple of planes grounded due to repair work or other issues. But in the case of Go Airlines' 27 aircraft fitted with Pratt & Whitney engines, they have been on the ground due to engine faults. (Venkatachari Jagannathan can be reached a v.jagannathan@ians.in)A /IANS