F-35A Crash Report

On October 19, 2022, an F-35A, part of a four-ship formation (LEGS 01-04), crashed upon approach to Hill AFB due to wake turbulence from the preceding aircraft. This turbulence led to errors in the air data application (ADA), causing unexpected flight control behaviors. The pilot's attempt to regain control by engaging full afterburner was unsuccessful, leading to an ejection. The pilot sustained minor injuries, but the aircraft, valued at $166 million, was completely destroyed.

What Happened?

On 19 October 2022, a four-ship of F-35A’s returned to Hill AFB after a training sortie. Upon approach to landing the #3 aircraft experienced wake turbulence from the preceding aircraft. The disruption in air flow resulted in erroneous inputs to the air data application (ADA).

As a result, the flight controls did not respond as the pilot expected. The pilot selected full afterburner in an attempt to recover to controlled flight.

Due to the aircraft’s low energy state and sideslip flight path, the pilot was unable to recover and initiated the ejection sequence. The pilot sustained minor injuries. The F-35 was a total loss to the tune of $166 million dollars.

Key Findings

• The accident investigation board (AIB) determined that the primary cause of the crash was the aircraft's departure from controlled flight due to air data system errors just before landing.

• A significant contributing factor was the pilot's failure to increase landing spacing from the preceding aircraft as per wake turbulence procedures.

Deeper Dive

Fighter aircraft typically recover in formation and land with reduced runway separation, treating the “center-line like a brick wall” (fighter pilot platitude). A.k.a. each member of the formation will land on alternating sides of the runway.

Utilizing this method, you are required to have 3,000 feet of separation between aircraft. This allows for a quicker recovery of large quantities of aircraft + saves a bit a gas.

“Wake Turbulence Procedures” require spacing to increase from 3,000 to 9,000 feet. The Supervisor of Flying (a pilot sitting in the control tower) is responsible for implementing Wake Turbulence Procedures whenever effect when a light crosswind (1-5 knots), tailwind, or light quartering tailwind condition is present.

The formation callsign was LEGS 01-04. LEGS04 was responsible for relaying the ATIS information to the formation on the recovery into the field. However, LEGS 04 did not relay wake turbulence procedures were in effect. While LEGS 04 did not relay this information the Accident Board highlighted that all pilots should have been aware to increase spacing based on the light winds. Tower will report winds when the formation was giving landing clearance.

During the final turn, LEGS 03, experienced a “burble,” which is something that most pilots experience when landing behind other aircraft. The data analysis showed the aircraft experienced wake turbulence for approximately 3 seconds.

The pilot verified he received a caution/warning for an AIR DATA DEGD (degrade) and audio notification which was the first indication something was out of the ordinary. Subsequently, when the aircraft failed to respond to inputs the pilot selected max afterburner in an attempt to recover.

The F-35 enterprise has over 600,000 flight hours and this is the first instance of this scenario.

Read the full report here: AIB Report