N999NAZenith Aircraft ZODIAC 601 XL · 2009

On March 29, 2013, about 1546 eastern daylight time, an experimental amateur-built Zodiac 601XL, N999NA, operated by a private individual, sustained minor damage during an in-flight upset near Collegedale Municipal Airport (FGU), Collegedale, Tennessee. The flight instructor was not injured and the private pilot was fatally injured. The instructional flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the local flight that departed FGU about 1537.

According to the flight instructor's written statement, the private pilot purchased the airplane about 3 weeks before the accident and was not familiar with it. The flight instructor agreed to provide instruction in the airplane and first wanted familiarize himself with it. The flight instructor flew the airplane solo uneventfully on two occasions, for a total of approximately 2 hours, with the second flight ending just before the accident flight began. After his second solo flight, the flight instructor shut down the engine and reviewed the airplane's characteristics with the private pilot. They then returned to the airplane, took their time entering the cockpit, fastened their seatbelts and secured the canopy; however, they were unable to start the engine.

The private pilot subsequently unlatched and raised the canopy to call for assistance from ground personnel. A ground person provided a charger for the airplane's battery. As he started to attach the charger, the private pilot unbuckled his seatbelt to assist; however, the ground person stated that the private pilot did not need to get out of the airplane as he did not require any help. The private pilot then put his seatbelt back on, more hastily than the first time, and appeared to fasten it again. The flight instructor thought he heard a "click," but could not see the private pilot's seatbelt with the center console between them. The pilots lowered the canopy and latched it a second time for the planned 20-minute flight.

About 5 minutes into the flight, the flight instructor heard a wind noise from behind their heads, which he did not hear on previous flights and thought that perhaps the canopy did not have a perfect seal to the fuselage. As the flight progressed, the canopy seemed like it may have opened a little more. By that time, the flight was headed back to the airport. The canopy then pulled up enough on the latches that the flight instructor could see daylight through the openings between the canopy and fuselage. The flight instructor attempted to pull the canopy down, but it instead opened completely and the airplane entered a negative g dive. He was not sure if the change in airflow or a control input by the private pilot caused the dive. The private pilot lifted out of his seat and ejected out of the cockpit. The flight instructor was able to grab the control stick, arrest the dive and land back at FGU uneventfully. Emergency responders later recovered the private pilot in a wooded area about 4 miles east of FGU.

The private pilot, age 77, held a private pilot certificate with a rating for airplane single-engine land. His most recent Federal Aviation Administration (FAA) third-class medical certificate was issued on January 13, 2012. At that time, he reported a total flight experience of 150 hours.

The flight instructor, age 45, held an airline transport pilot certificate with a rating for airplane multiengine land. He also held a commercial pilot certificate with ratings for airplane single-engine land and rotorcraft helicopter. He held a flight instructor certificate, with ratings for airplane single-engine, rotorcraft helicopter and instrument airplane. His most recent FAA second-class medical certificate was issued on October 29, 2012. The flight instructor reported a total flight experience of 4,750 hours; of which, 2,793 hours were in single-engine airplanes and 2 of those hours were in the accident airplane.

The experimental, amateur-built, two-seat, low-wing, fixed tailwheel airplane, serial number 6222, was assembled in 2009. It was powered by a Jabiru 3300A, 110-horsepower engine. The airplane's most recent conditional inspection was completed on November 13, 2012. At that time, the airplane had accumulated a total flight time of 57.8 hours.

Lovell Field (CHA), Chattanooga, Tennessee, was located about 13 miles west of the accident site. The recorded weather at CHA, at 1553, included wind from 360 degrees at 8 knots and a broken ceiling at 10,000 feet.

Examination of the airplane by an FAA inspector revealed minor damage to the fuselage and canopy. Examination of the canopy and the private pilot's seatbelt did not reveal any failures. The inspector was able to secure and release both the canopy and seatbelt without difficulty. The inspector also noted that the canopy fit was not aligned on the accident airplane and that safety wire and turnbuckles had been installed to the bottom rear edges of the canopy, to aide in the latching of it. While securing and releasing the canopy, she had difficulty determining when the canopy was latched or not.

An autopsy was performed on the private pilot by the Bradley County Medical Examiner's Office, Cleveland, Tennessee, on April 1, 2013. Toxicological testing was performed on the private pilot by the FAA Bioaeronautical Science Research Laboratory, Oklahoma City, Oklahoma. Review of the toxicological report revealed:

"Amlodipine detected in Liver

Amlodipine detected in Blood"

A Garmin GPSMAP 296 was recovered from the airplane and forwarded to the NTSB Vehicle Recorders Laboratory, Washington, DC, for data download. Data were successfully downloaded and plotted. Review of the plots revealed that the airplane departed FGU at 1537 and flew an approximate 6-mile right arc, around and back to the airport. At a GPS time of 1546:06, the airplane was at a GPS altitude of 2,356 feet and traveling at 99 knots. About 9 seconds later, the airplane had descended to a GPS altitude of 2,047 feet, in the vicinity of the accident site. During the following 3 seconds, the airplane had descended another 259 feet to an altitude of 1,788 feet at 1546:18, before the descent was corrected (for more information, see GPS Factual Report in the public docket).