ERA12FA565

The pilot's loss of control while performing a low-level aerobatic maneuver, which resulted in collision with terrain.

During a fly-in, the private pilot was participating in a three-airplane formation aerobatics demonstration with a student pilot-rated passenger onboard. Several witnesses observed the three airplanes flying from west to east in trailing formation, each slightly lower than the one in front. The first two airplanes in the formation performed a barrel roll. The third airplane, which was being flown by the private pilot, then entered a barrel roll; however the nose of the airplane "dropped" into an extremely low attitude as it came through the inverted arc of the roll. The roll then stopped, but the airplane was almost full nose-down in a vertical descent. The airplane then appeared to immediately begin pitching up, and the airplane's pitch attitude decreased to about 45 degrees nose-low. The pitch attitude continued to decrease, but the airplane began to oscillate rapidly about the roll and pitch axis. A few seconds later, the airplane's heading changed about 180 degrees while the airplane continued descending at a 30- to 45-degree nose-low attitude and continued to oscillate about the roll and pitch axis until it was lost from sight behind. The sound of impact was then heard and smoke rose from behind the trees. Examination of the accident site, airplane, and engine, did not reveal any evidence of any preimpact failure or malfunction that would have prevented normal operation of the airplane. During a barrel roll maneuver, it is critical to raise the nose high enough during the first 45 degrees of turn. Not doing so could result in a corresponding nose-low attitude and proportionally high airspeed when recovery is made. Insufficient back pressure could then result in a "dish out" (the airplane falling out of the maneuver) during the inverted portion of the roll. The pilot of the accident airplane was an experienced aerobatic pilot, but the co-owner of the airplane advised that, like all such pilots, he got rusty after long periods of inactivity. A few weeks before the accident, the pilot had commented to the co-owner that he would like for him to ride in the back cockpit and help him "brush up" on his barrel rolls. The co-owner agreed to ride with him, but they did not set aside a specific time to do that, and it was never accomplished. During the formation sortie, at first the accident pilot's rolls were crisp and tight, but the pilot fell farther and farther behind and his rolls were getting slower. The airplane's co-owner observed that the final barrel roll "dished out very badly" (the airplane fell out of the maneuver), which resulted in an extremely nose-low attitude followed by an accelerated stall. It is likely that the pilot recognized his position in relationship to the ground and aggressively applied aft stick in an effort to recover from the nose-low attitude, which resulted in the stall. On the day of the accident, the pilot had flown several formation sorties. The day was hot, and the formation activities were demanding. The accident flight was relatively long, and the co-owner of the airplane guessed it was about 45 minutes long. Most formation sorties were 30 minutes or less. The accident pilot was in his early 70s and was by far the oldest member of the flight. Due to the pilot's age, the demanding schedule, and the length of the formation sorties, fatigue could have been a factor, although it could not be conclusively determined.

Moontown Airport was a privately owned, uncontrolled airport, open for public use. It was located approximately 7 nautical miles east of Huntsville, Alabama. According to the Airport Facility Directory, 3M5 had one runway oriented in a 09/27 configuration. The runway was turf covered, and in good condition. The total length of the runway was 2,180 feet, and its width was 160 feet. Approximately 86 aircraft were based at the field and annual aircraft operations averaged 43 per day. Barrel Roll According to the International Aerobatic Club, the barrel roll is a combination between a loop and a roll. When doing the maneuver, the pilot completes one loop while completing one roll at the same time. The flight path of the aircraft during a barrel roll has the shape of a horizontal cork screw. During a barrel roll, the pilot always experiences positive Gs up to a maximum of about 2.5 to 3 Gs, and a minimum of about 0.5 Gs. Examination of the Barrel Roll Maneuver Examination of the flight path of an airplane during a barrel roll revealed that the maneuver included a constant variation of airplane attitude and position of the airplane's nose in all three axes. It consists of a rotation along the pitch axis (nose rotates upward, in a direction perpendicular to the wings) through the application of elevator input, followed by aileron input to rotate the airplane along its roll axis. Rudder input would then be applied to help assist the roll through the yaw axis (nose rotates sideways), by swinging the tail over the top. At the midpoint (top) of the roll, the airplane would be flying inverted, with the nose pointing at roughly a right angle to the general flight path. The airplane will have also gained altitude and travelled a short distance from the original flight path. Flying inverted, the airplane would continue through the roll, descending in altitude and returning to the original flight path. Upon completing the roll, the airplane should end up flying along the same flight path, and at roughly the same altitude at which the maneuver began. Further examination of a barrel roll maneuver also revealed that failure to raise the nose high enough during the first 45 degrees of turn could result in a correspondingly nose low attitude and proportionally high airspeed when recovery was made and insufficient back pressure could result in a "dish out" (the airplane falling out of the maneuver) during the inverted portion of the roll. An insufficient roll rate would also result in an overshoot of the intended recovery heading while an excessive roll rate would result in an undershoot. Too much or too little rudder would also produce the same results as too fast or too slow a rate of roll. Additionally, failing to scan ahead for the reference point and/or section line could result in a loss of orientation. FAA Low Altitude Waiver and Aviation Event Authorization According to the FAA, No aerobatic practice area or aerobatic contest box existed at, or in the vicinity of 3M5. A low altitude waiver for aerobatics was not requested by any of the pilots in the formation flight, nor was a certificate of waiver or authorization requested by the fly-in organizers or the airport in accordance with FAA Advisory Circular 91-45C. Aerobatic Flight According to the FAA, aerobatic flight means an intentional maneuver involving an abrupt change in an aircraft's attitude, an abnormal attitude, or abnormal acceleration, not necessary for normal flight. Review of 14 CFR Part 91.303 revealed that "No person may operate an aircraft in aerobatic flight— (a) Over any congested area of a city, town, or settlement; (b) Over an open air assembly of persons; (c) Within the lateral boundaries of the surface areas of Class B, Class C, Class D, or Class E airspace designated for an airport; (d) Within 4 nautical miles of the center line of any Federal airway; (e) Below an altitude of 1,500 feet above the surface; or (f) When flight visibility is less than 3 statute miles." Examination of the formation flights indicated however, that even though the formation flights occurred at an altitude of 1,500 to 2,000 feet above ground level in Class E airspace, near V54 which is a low altitude airway, the airspace was not associated with the surface area of the airport. Comparison of the formation flight's flight path to the Rocket Very High Frequency Omni-Directional Radio Range, 080 degree radial, also indicted that the formation flights were conducted more than 4 nautical miles from the centerline of the airway. Moontown Airport Annual Grass Strip Fly In Operations Manual Review of the section titled: "Flight Ops" in the Moontown Airport Annual Grass Strip Fly In Operations Manual revealed that it contained guidance specifying that: 1. Single aircraft low passes were at pilot discretion. 2. Formation passes were to be accomplished at treetop level or higher. 3. Pilots should not direct aircraft energy at the crowd below traffic pattern altitude. 4. Aircraft that were not capable of operating from the airfield should not perform "touch/go" maneuvers. 5. Missed "Op" or "Low and Dirty" passes were acceptable at pilot's discretion. No guidance however, was discovered in the "Flight Ops" section or in the rest of the document regarding aerobatic demonstrations during the fly in. Moontown Airport Managers guidance Moontown Airport also did not provide any guidance regarding aerobatics during the fly-in with the exception of an old poster that was hung in the fixed base operation at the airport and was written by the pilot involved in the accident when he was the airport manager several years before. Review of the document revealed that it referenced 14 CFR Part 91.303 though it referred to the regulation as "91.301". It also did not provide any specific guidance regarding aerobatic demonstrations during the fly in, but only contained general information from the airport manager which stated that: "Moontown Airport is beside the south edge of the 4 nautical mile airway clearance. The chart above depicts the airway outlined in purple. I continue to recommend aerobatic flight over the fields between Moontown Airport and Gurley, south of US 72 between 2200 feet MSL and 3500 feet MSL. Avoid Madison County High School on the north side of US 72 and the Hampton Cove community on the south side of the hills south of US 72. A good reference for the north boundary of this area is to be no further north than the line projected east of 3M5 runway 9-27. Huntsville approach limits approaching traffic to above 3700 feet in the Moontown area." Experimental Operating Limitations Review of the Experimental Operating Limitations Exhibition (Group III, Phase 2) that were issued by the FAA for the airplane revealed that a restriction existed in the document which stated that; "No person may be carried in this aircraft during the exhibition of the aircraft's flight capabilities, performance, or unusual characteristics at air shows, motion picture, television, or similar productions, unless essential for the purpose of the flight." According to the FAA, an airshow is an aviation event defined as an aerial demonstration by one or more aircraft before an invited assembly of persons. Airplane Co-owner's Statement According to the co-owner of the airplane, the pilot of the accident airplane was an experienced aerobatic pilot but, he advised that like all such pilots, he got rusty after long periods of inactivity. Many times he had watched him practice and any errors he observed were minor (mainly errors of style) and within the realm of safety. A few weeks before the accident the pilot had commented to him that he would like for him to ride in the back cockpit and help him "brush up" on his barrel rolls. He said that he had lately developed a tendency to "dish out." According to the Co-owner, a dish-out is not normally a dangerous error if enoug