Summary
A serious incident occurred at Naha Airport on June 14, 2018, involving two Japan Air Self-Defense Force (JASDF) F-15J aircraft (registrations 52-8850 and 32-8818) and a Bombardier DHC-8-402 (registration JA84RC) operated by Ryukyu Air Commuter Co., Ltd. The two F-15J aircraft, operating as a formation, entered Runway 36 without obtaining air traffic control clearance while the DHC-8 was on final approach with landing clearance. The air traffic controller subsequently instructed the F-15Js to vacate the runway and cancelled the landing clearance momentarily before re-issuing it. The DHC-8 landed safely. No damage to persons or aircraft was reported.
History of the Serious Incident
On the day of the incident, the Formation Leader and Wingman of the F-15J formation were on scramble-ready duty at Naha Air Base. At around 20:20 JST, a scramble alarm sounded, and both pilots taxied from the Alert Hangar. The Formation Leader, using UHF-1, contacted Naha Ground Control and received taxi instructions to taxiway E7, along with departure instructions. The Naha Tower controller decided to have the DHC-8 land first due to separation concerns and issued a "HOLD SHORT OF RUNWAY 36" instruction to the scramble aircraft at around 20:25. The Formation Leader read back "HOLD SHORT, 36," but later stated he did not remember the communication and believed he had received clearance to enter the runway for takeoff. The DHC-8 received landing clearance at 20:25:14.
The Formation Leader, dealing with heavy steering due to fully fueled external tanks and trying to hasten the slightly delayed Wingman, entered the runway around 20:26 without halting at the holding position marking. The Wingman, confused by the Lead Aircraft's action, followed onto the runway. The Naha Tower observed the incursion and immediately instructed both F-15Js to vacate the runway, simultaneously cancelling the DHC-8's landing clearance but instructing it to continue its approach. The scramble order was cancelled around the same time. After the F-15Js vacated the runway via taxiway E6S, landing clearance was re-issued to the DHC-8 at 20:26:42, and it landed at 20:27:21. The incident occurred at Naha Airport on Runway 36.
Additional Information
Radar track data showed that at the time the Lead Aircraft entered the runway, the distance to the DHC-8 was approximately 3.36 nautical miles (6,230 m). When the No. 2 Aircraft vacated the runway, the distance was approximately 1.33 nautical miles (2,450 m). The meteorological conditions at 20:00 JST included light rain showers, visibility 8,000 m, and wind from 310° at 12 knots. Both JASDF pilots held valid pilot certificates and medical certificates issued by the Ministry of Defense. Both F-15J aircraft had undergone required maintenance and technical inspections.