A Swiss Cheese Divert

Photo By Aniela Pendergast | The Swiss Cheese Model is a risk management tool demonstrating layers of active failures and latent conditions. Each slice, or layer, of risk mitigation has holes, representing weaknesses or potential failures. When the holes in each layer align, a trajectory of failure can pass through all the defenses, leading to a possible accident.  

UNITED STATES

08.01.2025

Courtesy Story

Naval Safety Command

By Lt. Cassia Larson & Lt. Cait Sylvester
Strike Fighter Squadron (VFA) 103 "Jolly Rogers"

The chosen location for Carrier Air Wing SEVEN’s (CVW-7) Air-to-Surface Strike Fighter Advanced Readiness Program (SFARP), Marine Corps Air Station (MCAS) Beaufort, South Carolina, was forecasted to have bright, sunny days and minimal weather conditions requiring pilots to fly primarily using flight instruments, rather than visual cues. Unfortunately for the strike fighter squadrons of CVW-7, they brought the dreary February Virginia weather with them to include chilly temperatures, drenching rains and — importantly — overcast ceilings.

At the brief time for a two-wave air-to-surface mission, Beaufort’s forecast weather for flight time was undeniably under instrument meteorological conditions, declaring a minimum 500-foot ceiling during time of flight and up to an hour post landing; all aircrew in the event understood an approach would be required to land back at Beaufort at the conclusion of the mission. Beaufort had a Precision Approach Radar (PAR) to all runways with a decision height of 200 feet above runway threshold, so with the 500 foot forecasts above the required minimums, aircrew expected to be able to land without incident. The risk of a potential missed approach was mitigated by setting an appropriate joker/bingo fuel state to ensure each aircraft would have sufficient fuel to return to Beaufort, attempt two approaches and then, if required, divert to Naval Air Station Jacksonville, Florida, the chosen weather divert option due to its optimal visual meteorological conditions forecast during the flight time.

After the two divisions of F/A-18Es and Fs launched and completed their mission, the formations split up into singles for weather and approach considerations. The first division of the Strike Fighter Squadron (VFA) 83 began their recoveries at Beaufort, which entailed getting vectored around a wide box pattern at 3,000 feet. Before any of the first wave landings the second division of VFA-103 Victory (VY) jets completed their mission in the working area and proceeded to the airspace exit point. The range training officer for the working airspace was a helpful relay from the field, keeping the division updated with current runway and airfield conditions so informed decisions could be made. The VY fighters decided the weather was proceeding as forecasted and their preflight fuel planning was sound for the required approaches, even with the wide traffic pattern and many jets in the sequence.

Meanwhile, as the Jolly Rogers executed their formation breakup in the working area, the VFA-83 division was in the ground control approach (GCA) box, receiving vectors to land. The first jet in the VFA-83 landed normally until the pilot attempted to taxi off the runway and momentarily lost braking action — necessitating the use of the F/A-18E emergency brake system. Without the assistance of anti-skid due to emergency brake selection, the aircraft brakes caught on the runway and resulted in a blown tire which created a foreign object debris (FOD) hazard on the active runway. Unwilling to accept the FOD risk to landing aircraft, Beaufort tower discontinued multiple aircraft approaches until the risk was addressed and the runway was clear. With only one aircraft landed, the VY division entered the landing GCA pattern as the Rams were being rerouted for their second approach.

VY 13, the third jet in the VFA-103 division piloted by the squadron safety officer with a “new guy” weapons systems officer (WSO) in the back seat, was sequenced into the GCA box behind VY 11 and VY 12. As the traffic pattern continued and jets were sent off approach frequency to individual GCA frequencies, the conditions degraded further. The active runway changed because of the FOD, sending jets on vectors even farther from the field to get the GCA box oriented in the correct direction and invalidating fuel planning assumptions.

Weather had also degraded due to a localized rain squall and despite Automatic Terminal Information Service calling the ceilings set at 500 feet, aircraft in the GCA box ahead of VY 13 were discontinuing their approach at minimums due to not having the runway environment in sight. Two VFA- 83 jets, now on a second missed approach, elected to execute emergency fuel diverts to Jacksonville.

In aviation risk management (RM), we often talk about the “Swiss Cheese Model” — meaning there is rarely a single causal factor for a mishap, but rather, a series of minor incidents line up like holes on a stack of Swiss cheese slices and create the conditions for a mishap. At this point, VY 13 was starting to see the confluence of multiple hazards and the aircrew turned to the final approach bearing on their first PAR with some apprehension. Stiff crosswinds during final approach made it difficult for the jet to remain on course. The approach controller opted for large heading changes to quickly address any deviations from course, which made overshoots difficult to avoid. Ultimately, at 800 feet, the controller informed the aircrew of VY 13 they were not in a safe position to land due to course line deviations and they directed them to execute a go around. Still in the clouds without the runway environment in sight, VY 13 executed their missed approach instructions.

Now was the time for decision making: Should they attempt another approach or should they avoid the risk and go ahead and request to divert to Jacksonville? The aircrew assessed they had enough gas remaining to try the PAR one more time at Beaufort, but after that, a bingo fuel profile would be required with near-perfect execution to make it to Jacksonville without violating standard operating procedures for minimum fuel on deck. In the downwind for their second and final approach at Beaufort, the VY 13 WSO provided the pilot the bingo information: direction to turn, airspeed required and the altitude needed to make it safely while burning the minimum amount of fuel. Ultimately, the second PAR at Beaufort ended as the first, with too many course deviations for the jet to land safely.

Executing missed approach for their second PAR with 3,800 pounds of fuel remaining onboard, the pilot of VY 13 immediately turned the jet toward Jacksonville and began to accelerate as required to climb up to flight level (FL) 430 for the emergency profile. The WSO declared an emergency to ensure priority handling from air traffic control (ATC). It required assertiveness from the aircrew to get what they needed; ATC attempted to issue heading vectors and level-off altitudes lower than the required cruise altitude of FL 430. The pilot remained persistent in flying the climb profile dictated by NATOPS (the Naval Air Training and Operating Procedures Standardization) and the WSO remained directive in telling ATC what they needed. Ultimately, ATC understood the situation. By the end of the affair, the aircrew of VY 13 landed safely at Jacksonville, no worse for wear except for their lack of wallets and cellphones. They fueled the jet up and launched for an uneventful landing back at Beaufort.

Many lessons were learned from this experience.

First, the importance of appropriate pre-flight fuel planning. In this case, all members of the Victory flight had planned for what initially seemed like a conservative amount of fuel remaining at the end of their event, considering a successful approach and landing were all but certain based on the weather at the airfield. However, after the Swiss Cheese Model had its say — including a fouled runway, poor weather, stiff crosswinds and ACTs under instruction — the fuel planning was exactly appropriate to get the crew to their planned divert.

Second, the importance of in-flight decision making and continuous reassessment of the RM matrix. With all the factors at play, the crew made the correct decision to divert, rather than risking another potential failed approach which would have put them in true fuel extremis.

Third, the need to be assertive. Air traffic control is a third crewmember in the flight, and crew resource management (CRM) applies to interactions with them as well. If an aircraft is in extremis, the aircrew are the only ones who truly know what they are experiencing in the cockpit. It’s important to communicate with ATC and be assertive.

Often, it’s easy to overlook the basic components of RM and CRM, but on days like these, aviators discover why it’s so essential to understand and execute them.

• Date Taken: 08.01.2025
• Date Posted: 08.01.2025 10:36
• Story ID: 544507
• Location: US