"Okay, roger. Good day." These were the last words Captain Zaharie Ahmad Shah communicated to ground control at Subang Airport before MH370 disappeared from the radar five days ago.

The pilot of the Malaysian Airlines fight MH370 to Beijing said this when acknowledging receipt of the communication code for the aircraft's tracking to be handed over to Ho Chi Minh City air traffic control.

And, shortly after that, the Boeing 777-200 went invisible.

"After MH370 left the KL International Airport about 12:40am on Saturday, everything ran smoothly for the first 40 minutes.

"However, we failed to detect any radar signal from the plane after handing over watch duty to the Ho Chi Minh City base a few minutes later," the National Air Traffic Control Centre (NATCC) assistant director Siti Sarah Lebai Abu said, today’s Sinar Harian reported.

The newspaper quoted Siti Sarah as saying that this was the first time such total communication breakdown has taken place in her 18 years as an air traffic controller.

On duty that fateful night, she said she was the last to speak to Zaharie from the control tower at Subang and she didn’t think then that there was anything amiss.

Siti Sarah told Sinar Harian that the plane went untraceable only after it entered the Igari island zone, the area of the South China Sea between the east coast of Peninsular Malaysia and southwest Vietnam.

She also rejected criticism that the Malaysian air traffic controllers had not been alert.

"This is not a play-play situation for us. We are responsible for the lives of up to 800 people at any one time. We don't ever slack off at work,” she added.

According the Malay-language daily, Zaharie, 53, joined MAS in 1981 and has chalked up 18,365 hours of flying time while his assistant, Fariq Abdul Hamid, 27, has 2,763 hours of flight time. Fariq joined MAS in 2007.

Meanwhile, Department of Civil Aviation director-general  Azharuddin Abdul Rahman ( left ) told reporters yesterday that there was a new signal.

"But the information can't be shared yet," Azharuddin is quoted saying, also by Sinar Harian , after a two-hour briefing session with Prime Minister Najib Abdul Razak.

However, he added that the search and rescue operations were still focused on the areas around Igari, although it had been expanded to 100 nautical miles around that location.

Yesterday, Berita Harian quoted military sources saying that MH370, which disappeared with 239 passengers and crew on board, was detected by military radar in Butterworth, flying north of the peninsula, heading towards the Sumatran waters, at 2.40am last Saturday.

However, Royal Malaysian Air Force chief Rodzali Daud later denied that the air force made such a statement.