As the small DA42 aircraft is not equipped with air conditioning system, Zhang donned a special kit called ocean commander immersion suit to keep warm.

When flying across the northern Atlantic Ocean from the Greenland to Iceland, Zhang encountered strong headwind, and the flight speed dropped to 110 to 120 kilometers per hour. "I realized there was no way to fly over the ocean on the day, so I turned back and landed in a small gravel airport on the east coast of the Greenland."

He got frostbite in ears when being out for two minutes checking the airplane at the airport.

High oil pressure is another difficulty Zhang has experienced. After taking off from the Urumqi Airport in Northwest China's Xinjiang Uygur autonomous region, he found the oil pressure of the left engine was in the red area, and immediately turned off the engine according to flight manual. "This is very challenging as well as dangerous. Fortunately, under the guidance of the control tower, I landed safely."

During the whole trip, Zhang was battling with various problems such as fuel supply, mechanical failure, and emergency maintenance and repair almost every day. But he has managed to overcome all the difficulties, be they big or small, and return safely.

"I was warmly received by overseas Chinese all the way along the journey, 99 percent of whom I did not know," he told Xinhua. "They brought me dumplings." Workers of Chinese enterprises in Kazakhstan even stayed at the airport for five hours, waiting to greet him.

Hangzhou, capital of East China's Zhejiang province, held a watering ceremony for him. Several fire trucks have practiced for two weeks for the ceremony.

Zhang stayed for more than one month and stopped over 20-plus airports in China during the trip. "Administrations at various levels in China offered me strong support." With the support, he has cut through China from northwest Xinjiang Uygur autonomous region to East China's Zhejiang province, and then turned northeast and left China from Heilongjiang province. "I flied over the Yangtze River, the Yellow River and the Great Wall in one flight. I am so glad," he said proudly.

What made Zhang prouder is that he may contribute a bit to China's aviation history. "We have land Silk Road and maritime Silk Road. We should also have an aerial Silk Road."