Aviation Accident Summaries

Aviation Accident Summary WPR20LA289

Redding, CA, USA

Aircraft #1

N1550G

Beech A36

Analysis

The pilot and three passengers were departing from a 2,420-ft-long runway when the accident occurred. A witness reported that the airplane appeared to be accelerating slowly, and that it suddenly rotated and appeared to lift off slightly before settling back to the ground, which caused the nosewheel to come back down to the runway surface. The airplane rotated abruptly a second time and remained in a nose-high attitude while approaching the departure end of the runway. The witness estimated the airplane’s speed as about 60 to 65 knots as it passed his location in a nose-high attitude. The witness added that, throughout the takeoff roll, the “engine sounded like it was producing full power and the propeller was producing full rpm.” Review of security camera recordings revealed that the airplane appeared to rotate about 700 ft from the departure end of the runway and remain in a nose-high attitude. The airplane briefly became airborne about 300 ft from the departure end of the runway and remained in a nose-high attitude before it settled back onto the runway surface about 2 seconds later and continued off the departure end of the runway: a post-impact fire ensued. Postaccident examination of the airplane revealed no evidence of any preexisting mechanical malfunction that would have precluded normal operation. A review of weight and balance information indicated that the airplane was about 23 lbs under its maximum gross weight at the time of the accident. Depending on the passenger seating configuration, which could not be determined, the airplane could have been within its center of gravity (CG) limitations or up to about 2 inches forward or about 1.75 inches aft of the CG envelope limit. Calculated takeoff performance for an airplane within the CG envelope given the atmospheric conditions and gross weight at the time of the accident showed that the airplane would have required 1,978 ft for a no-flap takeoff with no obstacle, or 3,558 ft for a no-flap takeoff to clear a 50-ft obstacle if takeoff power was applied prior to brake release. The extent of the pilot’s preflight takeoff performance planning and his takeoff technique could not be determined based on the available information. The circumstances of the accident are consistent with the pilot’s failure to recognize the airplane’s inadequate takeoff performance given the length of the available runway and his subsequent failure to abort the takeoff, which resulted in a runway excursion.

Factual Information

HISTORY OF FLIGHTOn August 27, 2020, about 0630 Pacific daylight time, a Beech A36 airplane, N1550G, was destroyed when it was involved in an accident near Redding, California. The pilot and three passengers sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations 91 personal flight.   A witness, who was a rated pilot and a law enforcement officer, reported that while at his desk, which overlooked the runway, he heard the noise of an airplane engine increase as it started its takeoff roll from runway 33. He saw the accident airplane come into view on runway 33; however, it “wasn’t accelerating at a normal rate for that type of aircraft.” The airplane continued the takeoff roll, accelerating much more slowly than he was accustomed to seeing; it rotated abruptly, “to a slightly steeper angle of attack than a normal takeoff and it appeared to lift off slightly before settling back to the ground; which caused the nosewheel to come back down to the runway surface.” The witness further stated that, as the airplane continued the takeoff roll, it [the airplane] again rotated abruptly and remained in a nose-high attitude while approaching the departure end of runway 33. As the airplane passed directly in front of the witness’s location, the airplane was in a nose-high attitude, at a speed of about 60 to 65 knots. The witness added that, throughout the takeoff roll, the “engine sounded like it was producing full power and the propeller was producing full rpm.” Two security cameras located near the witness’s location captured the accident airplane’s takeoff sequence (locations outlined in figure 1). Camera 1 initially captured the accident airplane during takeoff roll about 1,500 ft from the departure end of runway 33 at a camera time of 0643:31. The airplane continued its takeoff roll, and at 0643:39, the nose wheel appeared to lift off the runway surface, consistent with rotation, about 700 ft from the departure end of runway 33. (see figure 2.) The airplane continued in a nose-high attitude with the main landing gear remaining on the runway surface until the airplane traveled out of view of the camera frame at 0643:41. Camera 2 captured the airplane traveling into view at 0643:39 in a nose-high attitude, with the main landing gear remaining on the ground. The airplane appeared to briefly become airborne at 0643:42, while remaining in a nose-high attitude, about 310 ft from the departure end of the runway and settled back onto the runway surface 2 seconds later. The airplane exited the departure end of the runway and traveled down an embankment out of view of the camera. A ball of fire could be seen erupting from the tree line north of the runway. The witness provided a time versus distance calculation based on measurements between two points of the runway. He estimated the approximate speed of the airplane as it was passing the runway 15 visual approach slope indicator to be about 70.9 miles per hour, or 61.6 knots. Figure 1. Google Earth plot of camera locations, approximate rotation area, and runway distance remaining Figure 2. Camera 1 view of the accident airplane rotation PERSONNEL INFORMATIONReview of the pilot’s logbook revealed 463.3 total hours of flight experience. The pilot recorded a total of 38.3 hours in the accident airplane, of which 10.8 hours were without a flight instructor. Previous flight experience in the available logbooks was in a Cessna 150. The right seat passenger held a flight instructor certificate. Review of his logbook revealed 339 hours of total flight experience. He did not have any recorded flight experience in the accident airplane make and model. AIRCRAFT INFORMATIONThe airplane was equipped with six seats; two forward, two middle rear-facing seats, and two forward-facing aft seats. The airplane was equipped with a Whirlwind III turbonormalizing system as part of supplemental type certificate (STC) SA5222NM. The STC also included a maximum gross weight increase from 3,560 lbs to 4,000 lbs. The performance section of the airplane flight manual supplement for the STC stated that it was “not FAA approved;” however, when operating at the increased weights, the pilot should expect an increased takeoff distance of up to 30 percent. The supplement further stated that takeoff speeds were to be increased by 2 knots. The takeoff performance chart stated that, at 3,650 lbs, the takeoff rotation speed would be 73 knots. Utilizing the airplane’s weight and balance record and the weights of the four occupants, 54 gallons of fuel, and no baggage, weight and balance values were calculated for the accident flight. The airplane’s gross weight was estimated to be about 3,977 lbs. The rear passengers’ seating positions could not be determined nor could the positions of the forward and middle aft facing seats. The center of gravity (CG) was calculated using the passenger and seat locations in the most favorable position and was found to be within CG limitations in three of seven passenger and seat position configurations. Dependent on the seating positions of the rear passengers, the CG ranged varied from about 2 inches forward of the forward limit, to about 1.75 inches outside of the rear limit of the CG envelope. Given the atmospheric conditions at the time of the accident, the airplane’s gross weight, and presuming that its CG was within limits during the accident takeoff, the airplane would have required 1,978 ft for takeoff with flaps retracted, or 3,558 ft to clear a 50-ft obstacle. This calculated distance includes the 30% increase in takeoff distance when operating at the increased maximum gross weight allowed by the STC. METEOROLOGICAL INFORMATIONThe calculated density altitude at the time of the accident was 1,607 ft. AIRPORT INFORMATIONThe airplane was equipped with six seats; two forward, two middle rear-facing seats, and two forward-facing aft seats. The airplane was equipped with a Whirlwind III turbonormalizing system as part of supplemental type certificate (STC) SA5222NM. The STC also included a maximum gross weight increase from 3,560 lbs to 4,000 lbs. The performance section of the airplane flight manual supplement for the STC stated that it was “not FAA approved;” however, when operating at the increased weights, the pilot should expect an increased takeoff distance of up to 30 percent. The supplement further stated that takeoff speeds were to be increased by 2 knots. The takeoff performance chart stated that, at 3,650 lbs, the takeoff rotation speed would be 73 knots. Utilizing the airplane’s weight and balance record and the weights of the four occupants, 54 gallons of fuel, and no baggage, weight and balance values were calculated for the accident flight. The airplane’s gross weight was estimated to be about 3,977 lbs. The rear passengers’ seating positions could not be determined nor could the positions of the forward and middle aft facing seats. The center of gravity (CG) was calculated using the passenger and seat locations in the most favorable position and was found to be within CG limitations in three of seven passenger and seat position configurations. Dependent on the seating positions of the rear passengers, the CG ranged varied from about 2 inches forward of the forward limit, to about 1.75 inches outside of the rear limit of the CG envelope. Given the atmospheric conditions at the time of the accident, the airplane’s gross weight, and presuming that its CG was within limits during the accident takeoff, the airplane would have required 1,978 ft for takeoff with flaps retracted, or 3,558 ft to clear a 50-ft obstacle. This calculated distance includes the 30% increase in takeoff distance when operating at the increased maximum gross weight allowed by the STC. WRECKAGE AND IMPACT INFORMATIONThe airplane came to rest down an embankment and was mostly consumed by fire. All major structural components of the airplane were located within the vicinity of the main wreckage. Remains of the firewall, cockpit instrumentation, gearbox, seat structures, and control yoke were identified within the recovered debris. The fuel selector valve was in the right fuel tank position, and the fuel strainer was melted. The left flap actuator drive cable was separated from the flap actuator motor, and the actuator measured 1.5 inches, consistent with the flaps in the retracted position. The right flap actuator was separated from the wing and measured at 2.1 inches, which equated to the flap being extended between 0 and 5°. Flight control continuity was partially established throughout. Both aileron direct cables remained attached to the bellcrank and separated in tensile overload at the inboard ends. The carrythrough cables on both wings were fractured at the bellcranks. Elevator control continuity was not established due to impact and thermal damage. Both rudder control cables remained attached to the bellcrank and visible ends appeared cut consistent with recovery operations. Examination of the airframe and engine revealed no evidence of any preexisting mechanical malfunction that would have precluded normal operation.

Probable Cause and Findings

The pilot’s failure to recognize the airplane’s inadequate takeoff performance given the length of the available runway and to abort the takeoff, which resulted in a runway excursion.

 

Source: NTSB Aviation Accident Database

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