A Y-20 large transport aircraft attached to an aviation division under the PLA Western Theater Command flies at a predetermined altitude during a flight training mission on January 4, 2021. (eng.chianmil.com.cn/Photo by Liu Shu)

 
Two Y-20 large transport aircraft of the Chinese People's Liberation Army (PLA) Air Force carrying much-needed disaster relief supplies arrived in Tonga on Friday after traveling a record-breaking distance of more than 10,000 kilometers and withstanding challenges including the presence of volcanic ash.

After taking off from Guangzhou Baiyun International Airport in Guangzhou, South China's Guangdong Province on Thursday, the two aircraft arrived in Nuku'alofa, capital of Tonga on Friday after traveling more than 10,000 kilometers, China Central Television (CCTV) reported on Friday.

Food, fresh water, water purifiers and tents were all included in the supplies that weighed a total of 33 tons, CCTV reported.

It was the longest distance the Y-20 has traveled in an overseas mission known to the public, and it is probably also one of the most challenging missions the Y-20 has experienced, Song Zhongping, a Chinese military expert and TV commentator, told the Global Times on Friday.

While a single Y-20 is said to be able to carry more than 60 tons of cargo, the reason why the two Y-20s only carried 33 tons of supplies is because the cargo amount can affect the aircraft's total flying range, Song said, noting that the aircraft must have made stopovers during the flight to reach the long distance of 10,000 kilometers.

Fu Qianshao, a Chinese military aviation expert, told the Global Times that the Y-20 can also carry more fuel when loaded with less cargo.

The mission displays that the Y-20 is fully capable of intercontinental flight and has the ability to carry out complicated emergency transport missions as a long-range strategic transport aircraft, Fu said.

It is also the first time known to the public that the Y-20 has flown to the South Pacific, and it shows the well-preparedness of the flight crews and capabilities of the advanced navigation systems equipped on the aircraft, Fu said.

When announcing the mission on Wednesday, Senior Colonel Wu Qian, a spokesperson from the Ministry of National Defense, said that the Chinese military would need to overcome challenges including volcanic ash.

Volcanic ash is very threatening to aircraft, as it has the potential to damage the engines and hinder visibility, so the Y-20s must have prepared many contingency plans to deal with all kinds of emergencies, experts said.

After completing the transport mission, the Y-20s are scheduled to return immediately, CCTV reported.

The PLA Navy will on Monday send vessels and deliver a second batch of supplies, which will include larger items, like mobile plank houses, tractors, generators and water pumps, Zhao Lijian, a spokesperson from China's Ministry of Foreign Affairs, said at a routine press conference on Wednesday.

The use of military equipment was agreed to by both sides, as airline services are suspended due to the COVID-19 pandemic, according to Zhao.