WPR14FA182 · Boeing E75

The highly experienced air show pilot was attempting to cut, with the vertical stabilizer of his biplane, a ribbon that was suspended about 20 feet above and across the runway. He was performing the maneuver on the third day of an open house at a United States Air Force (USAF) base and had successfully accomplished the maneuver on the two previous days, as well as at many previous air shows. After the pilot rolled the airplane inverted for the pass, witnesses observed it descend smoothly to the runway and slide to a stop. As the airplane came to a stop, a fire erupted, and the airplane was completely engulfed in flames within about 90 seconds of the fire's start. The first fire suppression vehicle did not reach the airplane until more than 4 minutes after the fire began, and the fire was extinguished soon thereafter.

The investigation did not identify any preimpact mechanical deficiencies or failures of the airplane or any adverse weather conditions that contributed to the abnormal runway contact. Toxicology analysis detected therapeutic amounts of diphenhydramine, an over-the-counter sedating antihistamine, in the pilot's blood, which likely impaired his ability to safely complete the maneuver and resulted in the abnormal runway contact.

The pilot was found lying on the upper panel of the cockpit canopy, and the canopy was found unlatched but in its closed position, indicating that when the airplane came to a stop, the pilot was likely conscious and attempted to exit the airplane; however, he was unsuccessful. The investigation was unable to determine when the pilot released his harness restraint system. If he released his harness before attempting to open the canopy, he would have fallen onto the canopy, which would have significantly increased the difficulty of opening the canopy. Even if the pilot did not release his harness before attempting to open the canopy, airframe damage and the canopy opening geometry would have prevented the full opening of the canopy, limiting the pilot's ability to exit. Further, the canopy was not equipped with any emergency egress provisions, such as quick-release hinge pins. Finally, the pilot's lack of a helmet or any fire protection garments increased his susceptibility to thermal injury and reduced his useful time to effect an exit, particularly given the rapidity of the fire's spread.

Although initially a survivable accident, the combination of pilot egress difficulties, the rapid fire growth, and the more than 4-minute firefighting response time altered the final outcome. The USAF primarily based its Airport Rescue and Fire Fighting (ARFF) plan for the air show on Department of Defense (DoD) and USAF guidance. In preparation for the open house, the USAF show director had attended an International Council of Air Shows (ICAS) trade show and briefing, where he was provided with ICAS guidance material that advocated the highest state of readiness for the ARFF teams. This entailed prepositioning the ARFF equipment, with the ARFF personnel fully suited in their protective gear, ready for immediate travel to and engagement in the rescue and firefighting efforts. For undetermined reasons, either that information was not communicated to the show organizers and ARFF planners or the responsible personnel and departments elected to disregard it. The organizers and planners made the decision to maintain the facility's ARFF readiness state at the DoD-defined "unannounced emergency" level during the air show, instead of the highest state of ARFF readiness advocated by ICAS. Based on the available evidence, if the ARFF teams had been at the highest state of ARFF readiness, the pilot's likelihood of survival would have been significantly increased.

The hazards imposed by low-level inverted flight included inadvertent ground contact, impact damage, and fire. The pilot had multiple strategies available to manage or mitigate the hazards' attendant risks. These included ensuring that he was in appropriate physiological and psychological condition to operate safely, wearing appropriate protective clothing, and ensuring an appropriate level of airplane crashworthiness including occupant escape provisions. The availability of ARFF services represented the final element of the risk management process, necessary only if all the other strategies failed or were otherwise ineffective. In this accident, the pilot either intentionally or unknowingly weakened, defeated, or did not implement several risk mitigation strategies: he was likely impaired by medication, he did not wear any protective clothing, and his airplane was not well-equipped from an occupant-escape perspective. The combination of these factors then resulted in the pilot being fully dependent on the timely arrival of ARFF personnel and equipment for his survival. The failure of the ARFF personnel and equipment to be at their highest level of readiness and to arrive in a timely manner was not the first, but rather the last, failed element of the overall risk-management scheme.

Verbatim NTSB analysis and probable cause from the NTSB dataset