CEN21FA043

The accident flight was a planned four-airplane formation practice flight. A Beech J35 was the flight leader and departed first along with a Beech M35. The third and fourth airplanes departed shortly thereafter. After takeoff, the M35’s landing gear would not retract, and the M35 moved to the “route” position (about 3 to 4 airplane widths away from the J35) to troubleshoot the landing gear problem. The third and fourth airplanes departed the formation, and the pilot of the J35 directed the pilot of the M35 to take the lead position back to the airport. While on downwind before turning onto the base leg, the pilot and observer of the M35 heard a loud “bang/wham,” and the airplane violently shook. The M35’s propeller assembly separated from the airplane and the pilot performed a forced landing. The airplane sustained substantial damage to its fuselage and left wing. The J35 entered an uncontrolled descent, impacted terrain, and was destroyed by postimpact fire. Postaccident examination of the airplanes revealed that the J35’s propeller contacted the left forward side of the M35. Evidence of propeller contact was noted on the M35 engine, engine cowling, and nose wheel tire. Both airplanes were operating in the same landing gear and flap configurations at the time of the collision. A performance study showed that, about one second before the collision, the M35’s descent rate increased from 350 ft/min to 750 ft/min. Based on the available information, the accident is consistent with the J35 pilot’s failure to maintain separation from the M35 while maneuvering.

FFI Formation Guidelines and Standard Procedures (dated March 15, 2020) According to the Emergency Procedures section, Aircraft Malfunctions, When an aircraft malfunction or emergency occurs, call ‘Knock It Off’ and inform Lead of the problem. Normally, if the aircraft in distress is able to communicate with outside agencies and navigate, they should take the lead when offered. As much as possible, avoid flying too close to an aircraft with an emergency. Fly no closer than route formation, and do not distract the pilot of the emergency aircraft. The maintenance records for the J35 were not located during the investigation. On November 6, 2020, about 1638 central standard time, a Beech J35 airplane, N617Q, and a Beech M35 airplane, N338Z, were involved in a midair collision near Fredericksburg, Texas. The J35 was destroyed, and the pilot was fatally injured. The M35 sustained substantial damage; the pilot and pilot-rated passenger received minor injuries. Both airplanes were operated as Title 14 Code of Federal Regulations Part 91 personal flights. The pilot of the M35 stated that the accident flight comprised four airplanes with the intent of practicing formation operations in an area north of Gillespie County Airport (T82), Fredericksburg, Texas. The flight of four airplanes were involved in formation flight training per Formation Flying Inc. (FFI) training standards. The J35 (the flight leader) and the M35 departed together, followed by the third and fourth airplanes. Shortly after takeoff, the pilot of the J35 gave the signal to retract the landing gear and began a right turn; however, the M35’s landing gear would not retract. The pilot of the M35 then moved to the “route” position (about 3 to 4 airplane widths away from the J35) to troubleshoot the landing gear problem. The pilots of the third and fourth airplanes departed the formation and subsequently proceeded to the practice area to maneuver as a two-airplane flight. The pilot of the J35 stated that he would follow the M35 back to the departure airport and directed the pilot of the M35 to take the lead position. The pilot of the M35 made a slight right turn away from the other airplane and leveled the airplane on a downwind leg for the landing runway about 3 to 4 wingspans left (to the west) of the J35. Just before briefing the approach and landing plan, the pilot and observer of the M35 heard a loud “bang/wham,” and the airplane violently shook. The airplane immediately pitched down, and the left wing dropped. The engine sound went quiet, and engine oil began to accumulate on the windscreen. The pilot reported that he and the observer were unsure of the damage to the airplane. The pilot performed a forced landing to a grassy field which contained a few small trees. During the landing, the airplane impacted small trees, skidded, and came to rest upright. Numerous witnesses reported observing or hearing the midair collision. According to the witnesses, after the collision, one airplane(J35) descended rapidly toward the terrain and the other airplane (M35) was headed in a westerly direction. Witnesses lost sight of the J35 behind trees and observed a fireball and smoke. Figure 1 depicts the ground tracks of both airplanes before and following the collision. Figure 1. Ground tracks of accident flights. Toxicology testing of the pilot of the J35 at the FAA Forensic Sciences Laboratory found 64 (mg/dL) glucose in vitreous, and alfuzosin was detected in the blood and urine. Airplane Performance Study A National Transportation Safety Board Airplane Performance Study was completed by the Office of Research and Engineering. The study was based on Automatic Dependent Surveillance-Broadcast (ADS-B) data provided by the FAA and GPS data recovered from the M35’s Garmin Aera 660 handheld GPS unit. N338Z was equipped with ADS-B; however, the equipment was turned off due to the planned formation flight and operating as the non-lead aircraft. Recorded ground tracks showed that the J35 was ahead and to the left of the M35 during takeoff. About 1637:48, as the two airplanes were approaching a north heading in the turn, the J35 converged behind and below the M35, which had a descent rate of about 350 ft/min. (See Figure 4) Figure 4: Recorded ground tracks for airplanes near impact About 1637:50, the M35’s descent rate increased to about 750 ft/min, and the two airplanes collided at an altitude of about 2,430 ft mean sea level. The J35 accident site was located about 2.5 miles northwest T82, and 1.1 miles east of the M35’s forced landing site. The main wreckage sustained a postimpact fire and was destroyed (See Figure 2.). The landing gear was extended, and the flaps were in the retracted position. The propeller blades sustained leading edge gouging and chordwise scratches. Figure 2. N617Q Main Wreckage The M35 accident site was located about 3.6 miles northwest of T82, and 1.1 miles west of N617Q. The airplane sustained substantial damage to its left forward fuselage and the left and right wings (See Figure 3.). Damage consistent with propeller impact marks was noted on the left forward engine cowling, forward engine cylinders, and nose landing gear tire. The flaps were found in the retracted position. The airplane’s three-bladed propeller assembly had separated from the engine crankshaft. The propeller assembly was located on December 2, 2020, about 1,000 ft north of the estimated collision location. Figure 3. N338Z Main Wreckage.