Ashish and Sandhya Tanwar had gone on a Thailand tour last month.

Air Force pilot Ashish Tanwar's wife was the Air Traffic Controller on duty at Jorhat when his An-32 aircraft lifted off with 12 others on Monday afternoon, only to vanish from the radar about half an hour later. Today, she continues to remain in the dark.

The Flight Lieutenant's family in Haryana's Palwal is getting increasingly anxious. "My son and his wife, Sandhya, had come home last month, after which they left for Thailand on a weeklong vacation. Back then, Ashish assured us that he will be back soon. But now it's been four days since I have even received any news about him," the pilot's mother, Saroj Tanwar, told news agency ANI.

Saroj Tanwar believes that her son may not even be in the country anymore. "I am sure the aircraft has crossed into China. Why is the government not negotiating with Chinese authorities to fast-track his return? A search operation is on, but we have been told that they cannot locate the aircraft due to bad weather," she said.

The Air Force transport aircraft was making a 50-minute journey to the Mechuka Advance Landing Ground in Arunachal Pradesh when it went missing around 12.27 pm that day. The Air Force has deployed Mi-17 and ALH helicopters, besides Sukhoi Su-30 and C-130J fighter jets, in its efforts to find the missing aircraft. On Thursday, unmanned aerial vehicles were also pressed into service.

The Tanwars, however, aren't satisfied. "There are over four lakh army personnel in the eastern sector. Why can't they be deployed to look for our boy? They should also look into the possibility of the aircraft crossing into China," Udayvir Singh, the pilot's paternal uncle, told ANI. He has sought an audience with Prime Minister Narendra Modi and Defence Minister Rajnath Singh to put forth the family's demands.

According to Udayvir Singh, Ashish Tanwar opted for a career in the military because almost everybody in his family is either with the Air Force or Army. "He completed his early education from Kendriya Vidyalaya and later joined a B Tech course in Kanpur. After working with a multinational company for a while, he joined the Air Force in December 2013. He was commissioned as a pilot in May 2015," the news agency quoted him as saying.

Like her husband, Sandhya Tanwar is also a Flight Lieutenant with the Indian Air Force.

(With inputs from ANI)