Delhi International Airport Private Ltd (DIAL) has decided not to straighten the smallest runway 27, closest to the Dwarka side, that would have made it parallel to the main runway 28 and the third airstrip 29. It has, instead, sent a proposal to the aviation ministry for building another runway.'Straightening the smallest runway 27 will mean demolishing the budget terminal 1 and the other option of making this airstrip parallel to others is taking it towards the Palam technical area. Both these options are not viable. Hence, we have decided... have the fourth runway operational by 2020,' said a senior official.