T-bird crash blamed on pilot error

The Sept. 14 crash of a USAF Thunderbirds demonstration team F-16 at the Gunfighter Skies 2003 airshow has been blamed on pilot error.

The accident investigation board, headed by Col. Robert Beletic, released the results of its inquiry into the crash last Wednesday, determining that the pilot, Capt. Chris R. Stricklin, misjudged his altitude before beginning a Split-S maneuver after taking off as the last Thunderbird plane to launch during the team's planned airshow demonstration. It was the last event of the airshow.

More than 35,000 people watched in horror as the plane slid into the ground and exploded just off the runway, with Stricklin bailing out less than a second before impact.

The $20 million plane crashed between the runway and the control tower at Mountain Home Air Force Base. Stricklan sustained only minor injuries, no one else was hurt and, other than the plane's destruction, damage near the airfield was minimal. Environmental impact was limited to soil contaminated by JP-8 where the fuselage came to rest.

The crash occurred 25 seconds into the flight of the aircraft, known as Thunderbird 6. The pilot was performing the "Maximum Climb and Split S on Takeoff' maneuver when the mishap occurred. Mountain Home airfield elevation is 2,996 feet above Mean Sea Level (MSL). The Thunderbirds used a 3,000-foot altimeter setting for the demonstration.

The accident investigation board determined that Stricklin took off at the proper time, 25 seconds after Thunderbird 5, beginning a maximum climb at 55 degrees. At 4,670 feet Mean Sea level (MSL), 1,670 feet above ground level (AGL), the pilot initiated an unloaded roll to inverted. The target altitude to initiate the roll was 5,500 feet MSL, (2,500 feet AGL). The pilot's planned apex (the highest point of the maneuver) was 6,500 feet MSL (3,500 feet AGL), but his actual apex altitude was oly 5,760 feet MSL (2,760 feet AGL).

On the radio, Stricklin called "three five" (meaning 3,500 feet AGL) after reading 5,500 feet on the heads up display (HUD) altimeter in the cockpit.

The safety observer, upon hearing "three five," allowed the maneuver to continue, the board said.

The pilot then pulled back to complete the Split S. Upon reaching 90 degrees nose low, aimed straight at the ground, the board said Stricklin recognized that "something was wrong."

"He had in fact put the aircraft in a position from which it could not be recovered," the accident report stated. He then commanded maximum back stick pressure in an attempt to recover and rolled slightly left to ensure the aircraft would impact away from the crowd should he have to eject.

Upon realizing that he could not avoid ground impact, he ejected from the aircraft at 140 feet above the ground, 0.8 seconds prior to aircraft impact.

"The mishap pilot's ejection was successful and the aircraft impacted the ground on the opposite side of the show line from the crowd," the report stated.

"There is clear and convincing evidence that pilot error caused the mishap," the report added. "The pilot misinterpreted his altitude above the ground causing him to roll and apex approximately 1,000 feet below the target altitudes. He mistakenly interpreted 4,500 feet MSL as the planned 2,500 feet AGL roll altitude and 5,500 feet MSL as the target 3,500 foot AGL apex altitude. Thus, upon reading 5,500 feet MSL on the altimeter, he called "three five" and initiated a Split S that the aircraft was incapable of successfully completing prior to ground impact."

Three factors, the report said, "substantially contributed to creating the prospect for such a critical error.

"The requirement for demonstration pilots to real time convert MSL to AGL numbers, a maneuver with a limited margin of error, and a preconscious level of awareness created a situation more susceptible to pilot error."

Stricklin has been reassigned to a desk job in the Pentagon, although Air Force officials insisted he was not being punished for the incident.

The Thunderbirds canceled four airshows after the incident before it resumed flying the rest of its airshow schedule, with only five planes instead of the normal six.

The team is stationed at Nellis AFB, Nev.