History of Flight
On June 27, 2015, about 1353 central daylight time, a Christen Industries Pitts S-2B, registration N877UP, sustained substantial damage when it impacted terrain during an aerobatic flight at the Cameron Memorial Airport (EZZ), Cameron, Missouri. The airline transport pilot received fatal injuries. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as an airshow flight. Day visual meteorological conditions prevailed for the airshow demonstration flight that departed from EZZ about 1340. No flight plan was filed.
The pilot's flight demonstration card used during the airshow indicated that he planned to perform 10 aerobatic maneuvers. For the ninth maneuver, he planned to do a Lomcevak maneuver, an advanced aerobatic maneuver. An airshow pilot familiar with the accident pilot's routine reported that the accident pilot intended to do a 45-degree knife-edge climb, perform the Lomcevak maneuver, and then continue the knife-edge climb.
Video recordings taken by persons on the ground showed the airplane flying the planned routines. The eighth maneuver was a steep climb to a near stalled condition called a "chopper (helicopter) pass." After this, the airplane entered a dive to gain airspeed, flew straight and level for about 5 seconds, then performed a course reversal by pulling up into a left climb and turning back to the right before diving again. It then pulled up and flew straight and level for about 4 seconds before entering a 30-degree knife-edge climb. During the knife-edge climb, the airplane appeared to enter the Lomcevak maneuver by performing a climbing snap-roll to the left. The nose pitched down and the airplane tumbled two times to the left while descending. It then entered a left spin and completed about two and a half revolutions before impacting the terrain.
Pilot Information
The 50-year-old pilot held an airline transport pilot certificate with single-engine land, multi-engine land, helicopter, airplane instrument, and helicopter instrument ratings. He was also an instructor pilot with airplane single-engine, multi-engine, helicopter, airplane instrument, and helicopter instrument instructor ratings. He held a first-class medical certificate issued February 15, 2015. The pilot completed an insurance application on August 25, 2014, indicating 11,000 total flight hours with 200 hours in the accident airplane make and model. He held a Level 3 Statement of Aerobatic Competency from the FAA for solo aerobatics with a 500 ft base altitude limit in Pitts airplanes, with the Level 3 flight evaluation conducted on May 7, 2015.
Aircraft Information
The airplane was a Christen Industries factory-built, tandem two-seat, experimental single-engine Pitts S-2B biplane manufactured in 1985. It was equipped with a 300-horsepower aerobatic Lycoming AEIO-540-D4A5 engine, serial number L-22892-48A, powering a 3-bladed MT propeller. The most recent annual maintenance inspection was conducted on May 1, 2015, with a total aircraft time of 1,806 hours. The airplane had 1,819 total hours at the time of the accident. The engine had a total time of 141.2 hours since the last overhaul.
Wreckage and Impact Information
The airplane impacted trees and terrain in a shallow nose-down attitude with a high vertical descent rate. The engine compartment, fuselage, wings, and empennage exhibited crushing and buckling from ground impact, but the airplane remained intact. There was no post-impact ground fire. The engine compartment exhibited upward crushing, and the leading edges of the wings did not exhibit aft crushing. Flight control continuity was confirmed from all flight control surfaces to their respective cockpit controls. Elevator trim continuity was confirmed from the elevator trim tabs to the elevator trim control.
The engine was shipped to the manufacturer for examination. The examination revealed that damage to the engine would not preclude an engine run on a test stand. Due to impact damage, slaved parts (fuel servo, magneto harness, etc.) were used during the engine run test. The engine was started and operated at various rpm points including warm-up, run-ups, magneto check, rated run at 2,700 rpm for 10 minutes, idle, and acceleration check. The engine passed all points within prescribed limits.
The fuel pump was examined and displayed significant damage, including cracks in the body, separation at a screw-fastened interface, missing and loose screws. Screws had metallic material and blue-colored nonmetallic substance (consistent with cured thread locking compound) in their lower threads; internal threads in the pump body were severely stripped.
Additional Information
The Lomcevak is a family of aerobatic flight maneuvers where the aircraft, with almost no forward airspeed, rotates on chosen axes due to gyroscopic precession and torque of the rotating propeller. One type involves following a knife-edge roll by flipping the airplane end-over-end and into a spin, from which the pilot recovers control.
Medical and Pathological Information
An autopsy of the pilot was performed on June 28, 2015, at Frontier Forensics Morgue, Kansas City, Missouri. The cause of death was multiple blunt force injuries sustained in an airplane accident. A Forensic Toxicology Fatal Accident Report was prepared by the FAA Civil Aerospace Medical Institute. No carbon monoxide was detected in the blood (cavity). No ethanol was detected in the vitreous. Azacyclonol was detected in urine but not in blood (femoral). Fexofenadine (a non-sedating antihistamine) was detected in urine and blood. Ibuprofen (a non-steroidal anti-inflammatory) was detected in urine.
Tests and Research
The NTSB Vehicle Recorder Division received three image files containing video and audio capturing the accident. The videos were correlated to local time. The files showed the aircraft performing aerobatic maneuvers while producing a smoke oil trail throughout the flight. At 1351:56, the aircraft was straight and level. At 1351:58, it began climbing, then rolled left wing down. At 1352:02, it performed a 360-degree rolling maneuver resulting in tumbling toward the ground, similar to a Lomcevak. The engine sound became faint and smoke oil dissipated. At 1352:11, tumbling continued and smoke oil reappeared with engine sound. At 1352:12, the tumble ended and the aircraft descended nose-down. At 1352:13, engine sound ceased as the aircraft impacted the ground.