Dangerously close, increasingly common

On June 11, 2024, VFA-22, an F/A–18F Super Hornet squadron stationed at Naval Air Station Lemoore was assigned to take advantage of the clear weather to conduct basic fighter maneuvers (BFM) training for three of its junior aircrew in the Lemoore military operations area (MOA) that surrounds the Central Valley airfield.

Around the same time, four light civilian aircraft took off from four different local airfields, also looking to take advantage of the clear weather for a little visual flight rules flying of their own. These unrelated plans would result in a near-midair collision (NMAC) between the F/A–18Fs and one of the civilian aircraft before 2 p.m. local time.

BFM is the most dynamic maneuvering F/A–18 aircrew execute during their various tactical training syllabi. Nothing matches the white-knuckle intensity of closing to within 500 feet of another aircraft at a combined closing speed of more than 700 knots and executing a 7.5-G break turn.

These maneuvers were to be flown within an MOA above and around the airfield that spans roughly 30 nautical miles from east to west, and 70 nm north to south. The vertical boundaries vary by sector, starting as low as 5,000 feet msl at the northern and southern ends.

The F/A–18F crews briefed and took off from NAS Lemoore, climbing quickly into the Lemoore MOA. The flight executed a “G-warm” maneuver and set their “war,” establishing ground rules for the simulated combat evolution including a "hard deck" of 5,000 feet agl, with unlimited maneuvering above that minimum altitude. As the pilots prepared, the local controller, "Showtime," began issuing traffic advisories. Over the next 10 minutes, the two F/A–18Fs (call sign "Viper") transited almost the entire length of their assigned airspace in search of clear air to train in. Viper was given positional callouts to three of the four VFR aircraft operating near or within the Lemoore MOA. Critically, however, the fourth VFR aircraft, climbing slowly in the hot, dry air, had not yet pierced the floor of the MOA, and as such was uncalled. Later, radar track analysis would reveal a steady 250 fpm rate of climb into the Lemoore MOA before the aircraft was first reported to the F/A–18Fs.

The F/A–18F pilots, believing they had a 10-nautical-mile bubble free of traffic, began to set up for their first planned BFM set and unknowingly positioned themselves almost directly in the flight path of the slow-climbing aircraft. In the two minutes before the NMAC, Showtime gave the lead F/A–18 six VFR traffic calls, the second-to-last and most important of which was missed by the Super Hornet aircrew because they were talking to the other Viper crew. Having missed this last callout, the fighters began their fight—and rapidly maneuvered downhill toward the unseen and unknown traffic.

The fourth VFR aircraft did not contact the local controller during its slow climb to and through the bottom of the Lemoore MOA. The aircraft ended up directly in the path of two oncoming F/A–18Fs, which were pure nose low, at a high angle of attack with limited maneuvering options. A serious, probably fatal, collision was only avoided by the extraordinarily high situational awareness of the senior pilot, one of the squadron training officers, and a TOPGUN graduate with four times the combined flight experience of the other three crewmembers.

At the last possible second, both F/A–18Fs executed maximum-performance pulls to gain separation from each other and the VFR traffic. The civilian VFR pilot may have never even seen the F/A–18s they almost collided with. Post-event attempts to find the aircraft were unsuccessful, as the VFR track was lost over the coastal mountain range a short time later. Postflight analysis of radar tracks and aircrew statements led to a conservative estimate of a pass within 400 feet.

This entire situation was handled by a single controller who had already provided traffic advisory calls to the military aircraft and three of the four civilian VFR aircraft, all of which were within 10 nm of the F/A–18s, yet only one was responding to air traffic control.

That narrative is not unique: Every Lemoore ready room has one or more aircrews with stories to tell about a close pass or NMAC with VFR traffic in the MOA. The investigation of the June 11 event revealed that VFR traffic has grown over the past five years, and the number of near misses has steadily increased. FAA regulations permit civilian traffic to freely transit MOAs with only warnings that military training may occur within the MOA. The Lemoore MOA operates under a locally based controlling agency with a traffic advisory frequency to assist VFR traffic in avoiding active BFM flights. However, based on interviews with Lemoore controllers, fewer than 50 percent of VFR traffic utilize this frequency.

The presence of a highly experienced aviator preventing a tragedy at the last second is not guaranteed. The Lemoore flight line continues to utilize the Lemoore MOA; thus, the probability of a fatal midair collision is high if nothing changes.

Fortunately, effective mitigation is already available to all who fly VFR through the Lemoore MOA. It has a civilian traffic deconfliction frequency that is published and available to anyone. The Showtime controllers of NAS Lemoore are among the best in the world at coordinating traffic between high-speed, rapidly maneuvering fighter jets and VFR traffic enjoying the freedom of the skies. The enhanced situational awareness these traffic advisories provide on both VHF and UHF frequencies improves the safety of everyone who uses them.

If all four VFR aircraft transiting the Lemoore MOA on June 11 had been in two-way communication with Showtime, there's a solid chance this entire episode wouldn't have occurred. If nothing else, utilizing the available VFR frequency gives all aviators valuable radio practice with controllers who are patient and proficient dealing with student pilots from one of the two fleet replacement squadrons operating at NAS Lemoore.

ATC radar services don’t guarantee safety. Even the F/A–18F Super Hornet's incredible combat systems are fallible, especially when aircrew focus on squeezing maximum performance out of their aircraft. Nobody takes off with the intention of not reaching their destination safely. It is imperative that everyone who takes off into those bright, clear skies uses every tool available for not only their safety but the safety of those around them.

Lt. Cmdr. Paul “LB” Shen is a weapon system officer currently assigned to Strike Fighter Squadron 22 attached to Carrier Air Wing One 17. He is a graduate of the Aviation Safety Officer course and has been flying F/A–18Fs since 2014.