It was a trip down memory lane, heart-wrenching memories, for a group of pilots and the relatives of late Hump pilots. Huang Zhiling listens to their stories to file this report from Xinjin, Sichuan province.

Moon Chin, 99, revisits Xinjin Airport in Sichuan, where he flew from and landed many times during World War II as a "Hump" pilot. Huang Zhiling / China Daily

Sitting on a wheelchair, Moon Chin looked intensely at a plane about to take off on the runway in the Civil Aviation Flight University of China in Xinjin county, Sichuan province.

"The last time I landed in this airport or flew over it was 67 years ago," says the 99-year-old American, who was a "Hump" pilot during World War II. The Hump was the name for the eastern end of the Himalayan Mountains.

From 1942-45, weapons and other cargo were transported from India to Yunnan province using the arduous former Burma (Myanmar) roads and the Hump air route over the Himalayan Mountains as China's land and water routes were cut off by the Japanese.

Chin flew over the Hump many times and also transported weapons and cargo from Kunming to the Xinjin Airport, the largest airport for bombers in Asia during WWII.

He is best known for setting a world record by using a 22-seater aircraft to transport 76 people on May 8, 1942.

Once his DC-3 plane from Kunming touched down at the Myitkyina Airport in Myanmar, Burmese refugees elbowed their way into it to escape the gunfire of the advancing Japanese troop. A total of 76 people managed to get on the small aircraft, including General Jimmy Doolittle who led the first retaliatory air raid on Japan after the Japanese bombed Pearl Harbor on Dec 7, 1941. The plane headed for Calcutta, India.

On Sept 16, Chin, 98-year-old Peter Coutiere - an American pilot who flew 680 missions over the Hump - and 15 relatives of late American Hump pilots started their self-financed, four-day visit to Sichuan.

From 1935-36, Chin lived in the home of a warlord near a church in Chengdu. During his visit to the city this time, he retraced his footsteps and was pleasantly surprised to find the church on the same spot.

But most of the American delegates with him had never visited Sichuan before and had taken the trip to fulfill their fathers' wish of revisiting China.

Eve Coulson, 60, is the daughter of Hump pilot Elbert Coulson.

From February to October 1944, her father flew over the Hump 99 times. On Sept 1 that year, when flying from Yibin, Sichuan, to Myanmar, his plane's two engines broke down and the aircraft crashed in northern Myanmar. His copilot perished in the accident. His body was never found.

Elbert Coulson fell on top of a tree in the forest. He was 27 years old then and had to survive on leeches for six days before he was rescued by some Burmese. He returned to Kansas, the United States, the following year and worked as a radio announcer. Soon after, he married Joan Williams, who worked in the library of the Kansas City Star newspaper.

"Dad told Mom how he wanted to revisit China. But Mom told him she would not wait for him if he went to China. Dad had never visited China again," Eve Coulson says.

While visiting the Xinjin Branch of the Civil Aviation Flight University of China, Eve Coulson received a special gift from the university's president Wang Xiaolong - stones used to pave the Xinjin Airport.

Another family member of a former Hump pilot, Stephen Loane, 50, says his father - captain Ernest Loane - lived in China for eight years, and his two elder brothers were born in Shanghai in 1946 and 1948. Ernest Loane made 453 trips across the Hump.

"I will tell the story of my father (in China) and better understand what he did and why he loved China very much," says Loane, a computer software engineer in San Francisco, California.

Showing a picture of his father, Loane points to the message in Chinese on the jacket that reads: "I am an American pilot here in China. Please help."

"My father told me the Chinese did help American pilots after they survived the crash," says Loane, who is impressed with a stone roller on display at the Civil Aviation Flight University of China.

"Instead of machines, Chinese peasants - old and young - used their hands to operate stone rollers to make the airport flat. My father was amazed and quite grateful to their efforts," says Loane, who has never visited China before.

"It is very meaningful to see China grow after years of struggle," he adds.

During the American delegation's visit, Chen Yingming, an 89-year-old expert in the history of aircraft, came from his home in the western suburbs of Chengdu to meet Moon Chin.

"The day when the Japanese army took over Hong Kong in December 1941, I was there. Chin piloted the last flight leaving Hong Kong amid the deafening gunfire. I have never met Chin before, but he has been my hero for seven decades," Chen says, before giving a photo album of aircrafts to Chin.

Chen told students at the Civil Aviation Flight University of China to remember what Hump pilots did for China.

"Without their sacrifices, it was difficult for the Chinese to win the War against Japanese Aggression," he says.

By the end of the war, 650,000 tons of gasoline, munitions and other supplies were flown over the Hump - perhaps the most dangerous route in air transport history, running from northeastern India across Myanmar to Kunming.

According to records, on a single day in August 1945, more than 1,000 round trips were made across the mountains, carrying a payload of more than 5,000 tons.

With just a map, a compass and a radio signal to navigate, the Hump, which includes ridges exceeding 4,500 meters, had witnessed numerous air crashes and was nicknamed "Aluminium Trail" because pieces of aluminium from crashed planes could be seen along the way.

Contact the writer at huangzhiling@chinadaily.com.cn.