An investigation by NK News‘s sister site NK Pro on Monday raised questions about how and why – in light of United Nations sanctions – Air China is able to purchase jet fuel when its aircraft go to North Korea.

Photos obtained during the NK Pro investigation showed that on at least seven times since 2016, the Chinese flag carrier’s jets were photographed connected or near to Air Koryo fuel tanker vehicles at Pyongyang’s Sunan International Airport (FNJ).

“Air China operates Beijing-Pyongyang-Beijing routes with Boeing 737-700,” an airline spokesperson explained to NK Pro after reviewing the photographs last week. “Aircraft will be fueled for one-way flight Beijing-Pyongyang when departing from Beijing and refueling will be done in the Pyongyang airport for the return flight.”

But while UN sanctions don’t specifically prohibit foreign airlines from purchasing jet fuel in North Korea, UN Security Council 2270 has since March 2016 prohibited the DPRK from importing it in almost all circumstances.

That would theoretically make aviation fuel extremely scarce in the DPRK – and therefore expensive – raising questions as to why it would ever be provided by North Korean authorities to Air China.

Furthermore, aviation experts told NK Pro that the Boeing aircraft Air China uses on the route are more than capable of flying the round-trip from Beijing on a single tank, raising further questions about the airline’s need to regularly refuel in North Korea.

NK PRO INVESTIGATION: PHOTOS OF AIR CHINA REFUELING IN PYONGYANG RAISE QUESTIONS ABOUT SUPPLY-LINES

As a result, sources suggested there were two possible explanations for Air China’s fueling activities in North Korea.

Firstly, load factors might create circumstances which, for safety reasons, Air China needs to purchase fuel in a foreign airport even if it costs more than at their home base.

Secondly, given the PRC is thought to be the main source of crude oil for the DPRK – which the North may refine at its Pongwha Chemical Complex into jet fuel – it’s possible that Air China might be buying fuel in Pyongyang because it’s actually cheaper than in Beijing.

But while pilots, analysis of 737 technical manuals, and aviation experts showed that the photographs largely supported Air China’s explanation, the investigation showed it was impossible to rule out that the planes might actually be defueling while in North Korea.

However, transferring illicit jet fuel to North Korea via Air China defueling would not be an efficient way to replenish the DPRK’s supply.

“It would take a while to build up a strategic reserve of fuel,” said Justin Bronk of the Royal United Services Institute (RUSI) in London.

Nor would it be simple, requiring aircraft modifications that would be easy for foreign maintenance teams to spot.

Overall, while Air China’s fuel transfers do not appear to be directly prohibited by UNSC sanctions, the issue could prove problematic for the airline from other perspectives.

In particular, U.S. and South Korean unilateral sanctions against the North could complicate fueling practices there — even when an airline is merely topping up.

Both the U.S. and South Korea have since December 2016 designated Air Koryo as a sanctioned entity and the fuel tanker connecting to the Air China planes regularly bears the logo of Air Koryo — suggesting it might be a party to any transactions.

Secondly, if any payments are made in U.S. dollars, these could create exposure for Air China relating to wide-ranging U.S. unilateral sanctions on North Korea.

Finally, if the entities involved with fuel transfers on the DPRK side have been designated by the Security Council, Air China could even encounter additional problems at a UN level.

Air China declined to comment on further questions from NK Pro about where the fuel comes from in North Korea, which entities are involved in transactions relating to its provision, or relating to the currency fuel may be purchased in.

Edited by Oliver Hotham

Featured image: NK Pro