TAIPEI (Taiwan News) — Multiple aircraft spotters on Wednesday (Jan. 13) detected a U.S. Navy surveillance drone flying just off the coast of southwestern Taiwan, well within the country's air defense identification zone (ADIZ) and possibly over the city of Kaohsiung.

At 12:12 a.m. on Wednesday, aircraft spotter CANUK78 reported that a U.S. Navy MQ-4C Triton headed toward the South China Sea. The map included in the tweet showed the aircraft flying through the Bashi Channel off the southeast coast of Taiwan.

The Facebook page of Taiwanese aircraft spotter Southwest Airspace of TW (台灣西南空域) at 12:52 a.m. stated that the Northrup Grumman unmanned aerial vehicle (UAV) with the Mode-S hex code AE5C74 had passed through the Bashi Channel. The flight took place several hours after three PLA Shaanxi Y-8 aircraft had intruded into the southwestern corner of Taiwan's ADIZ.

The Beijing-based South China Sea (SCS) Probing Initiative at 2:08 a.m. described the aircraft as going on a "midnight surveillance mission" near China and in the South China Sea. At 6:37 a.m., Twitter user Ketagalan wrote that it flew from the Bashi Channel and into the South China Sea and included a map from ADSB Exchange appearing to show the drone taking a sharp turn deep inside Taiwan's ADIZ and toward its southwest coast.

At 6:54 a.m., Ketagalan observed that it had appeared off the coast of the city of Shantou in Guangdong, China. By 7:18 a.m., CANUK78 showed the plane doubling back from the South China Sea and toward Taiwan's southwest ADIZ.

Aircraft spotter Golf9 at 7:57 a.m. that the aircraft had originated from Guam and was joined by Boeing KC-135 Stratotanker from Kadena Air Base in Okinawa in flying south of Taiwan. An ADSB map of the UAV's flight at the time showed it appear to fly over Kaohsiung City, specifically over Shoushan, commonly known as Monkey Mountain.

(ADSB Exchange screenshot)

Twitter user Evergreen Intel at 8:02 a.m. stated that the UAV was being tracked with the use of Multilateration (MLAT) by ADSB Exchange and that its position at the time was to the southwest of Taiwan. The ADSB Exchange map included in the tweet shows the drone flying off the southwest coast of Taiwan.

At 8:14 a.m., Twitter user Oceanner spotted the MQ-4C Triton off the coast of Kaohsiung City. 20 minutes later, SCS Probing Initiative reported that the plane was detected leaving the South China Sea at 8 a.m. after carrying out an "8-hour midnight mission."

Military aircraft spotter RivetJoint at 9:06 a.m. tweeted that the aircraft was flying near Taiwan at an altitude of 46,000 feet. RivetJoint also included a map appearing to show it flying directly over Kaohsiung.

Northrop Grumman MQ-4C Triton
Heading towards the

— CANUK78 (@is_keelu)

USN MQ-4C (AE5C74) is flying a midnight surveillance mission near , , Jan 13.

— SCS Probing Initiative (@SCS_PI)

USN MQ-4C Triton 00:00 左右經巴士海峽飛至中國沿岸空域巡弋

— Ketagalan (@CCCDSLR)

MQ-4C Triton

168460

— CANUK78 (@is_keelu)

MQ-4C Triton near at 46,000 ft
AE5C74 168460

— RivetJoint (@JBWiese75)