Budget passenger airline IndiGo on Friday said it is awaiting certain clarifications regarding GST rates applicable on import of engines which it requires for its grounded A320ceo aircraft. The airline also asserted that its pre-scheduled operations are normal and flights are operating “on-time”. “We have 4 neo aircraft grounded due to 4 engines stuck at customs as we are awaiting certain clarifications post the implementation of GST. This has lead to unplanned flight cancellations,” IndiGo said in a statement. “There is no new development pertaining to the grounding of neos. As we have said on our June earnings’ call, there were instances when up to nine neos were grounded due to inadequate spare engines.” The airline added that at present eight of its neos have been grounded due to unavailability of spare engines. “These are already factored in our revised schedule which was finalised in June and there are no additional flight cancellations on account of these neos,” the statement added.