North Korean passenger planes were spotted flying outside of Pyongyang at another domestic airport for the second time in the last week, marking a sudden surge in air activity ahead of the upcoming Eighth Party Congress.

This year, Air Koryo planes were mostly grounded due to travel restrictions meant to prevent the spread of COVID-19. But the rare flights, first detected by NK Pro on Wednesday, could signal that the Party Congress will start in the first few days of January, since they might be bringing event attendees to Pyongyang. State media has so far only reported that the Party Congress will be held within the first 10 days of the month.

On Dec. 22, satellite imagery and ADS-B tracking data confirmed that an Air Koryo An-148 passenger jet made a roundtrip from Pyongyang to Wonsan. Now, satellite imagery also reveals more flights leaving Pyongyang International Airport in the following days.

Two planes were even spotted parked at the Orang airport, located in the northeast along the coast just south of Chongjin, in Planet Labs medium-resolution imagery taken on Dec. 25.

At the same time, four large passenger planes were missing from their typical parking spots at the Pyongyang airport: two Tu-154s, one Il-62 and one Tu-134. 

The larger plane visible at Orang airport on Dec. 25 appeared to be one of the Tu-154s (136 seats), while the other was likely the Tu-134 (72 seats), based on their measurements in the Planet Labs satellite images.

The other missing planes on that day were not visible in available imagery of the other main airports near Sinuiju, Samjiyon, Wonsan or Hamhung, nor at primarily military airfields elsewhere around the country.

In addition to the confirmed flights to Wonsan on Dec. 22 and to Orang on Dec. 25, planes appeared to be coming and going from Pyongyang on Dec. 20, Dec. 21 and Dec. 24, according to Planet Labs imagery.

A Tu-154 and Tu-204-100B (176 seats) were missing from their parking spots in Pyongyang on Dec. 20 at 11:40 a.m. local time. The Tu-154 was back the following day around the same time, but the Tu-204-100B was missing again.

On Dec. 24, all planes were once again parked at the Pyongyang airport at 11:07 a.m., before a Tu-154 was seen heading to the runway in another image taken 20 minutes later.

Around 3,000 people from the North Korean military and the country’s political sphere are expected to attend the upcoming Party Congress, according to the Seoul-based Daily NK — some of whom have reportedly already been traveling to Pyongyang by train and road since around Dec. 22.

Given the proximity to the big upcoming event and the fact that these passenger planes have otherwise been grounded for most of the year, it is likely that Congress attendees are among those taking the special Air Koryo flights this week.

Meanwhile, none of the Il-76 cargo jets were seen leaving their spots in Pyongyang in recent weeks, though these planes have appeared the busiest this year. They were often seen in Planet Labs imagery coming and going or moving to a hangar at the airport, possibly for maintenance.

Edited by Kelly Kasulis