Aviation Accident Summaries

Aviation Accident Summary WPR21LA287

Chandler, AZ, USA

Aircraft #1

N222HC

BEECH A36TC

Analysis

The pilot reported that before takeoff he calculated the airplane’s takeoff weight, which he determined to be near the maximum gross takeoff weight with a center of gravity (CG) on the forward edge of the CG envelope. The takeoff calculations assumed that the airplane could sufficiently clear a 50-ft obstacle during the takeoff ground roll. During the takeoff, the pilot reported that the engine sound and indications were normal for the takeoff roll but that acceleration was slightly slower and the ground roll longer than predicted. The pilot did not abort the takeoff because he thought that the slower acceleration and longer ground roll were related to the outside air temperature, which was about 91oF. After liftoff, the pilot kept the nose lowered to build airspeed. After the landing gear was retracted, the airplane did not accelerate or climb. The airspeed was getting slower, and the stall warning was activating intermittently. As the airplane neared the end of the runway, the pilot aborted the takeoff and landed the airplane just beyond the departure end of the runway in dirt. The airplane slid on its belly and subsequently collided with an airport fence. The wings were substantially damaged, and a postimpact fire ensued. Examination of the engine revealed no preaccident mechanical failures or malfunctions that would have precluded normal operation. It is likely that the combination of a high gross airplane weight and a high outside temperature resulted in a ground roll that was longer than the pilot expected based on his takeoff calculations. By the time that the pilot aborted the takeoff, the airplane was operating at or near the stall speed and was thus not able to gain altitude.

Factual Information

On July 10, 2021, about 0730 mountain standard time, a Beech A36TC, N222HC, was substantially damaged when it was involved in an accident at Chandler, Arizona. One passenger sustained serious injuries, and the pilot and two passengers sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, before takeoff, he calculated the takeoff weight to be 3,794 pounds and the center of gravity (CG) to be on the forward edge of the CG envelope. The maximum certified gross weight for the airplane was 3,833 pounds. The pilot also calculated the takeoff distance to clear a 50 ft obstacle to be about 3,000 ft for an outside temperature of 90oF. The length of the runway to be used for takeoff was 4,400 ft. The pilot reported that the preflight inspection and the engine start, taxi, and pretakeoff checks were normal. The pilot further reported that the engine sound and indications were normal for the takeoff roll but that the airplane’s acceleration was “slightly slower than expected” and the ground roll was “longer than predicted.” The pilot did not abort the takeoff because “given the high OAT [outside air temperature], this was not…indicative of a problem.” He did not recall the speed for rotation but reported that it was within the range for takeoff. After liftoff, the pilot lowered the airplane’s nose to allow the airplane to accelerate. After the landing gear was retracted, the airplane did not accelerate or climb, the airspeed was getting slower, and the stall warning was activating intermittently. As the airplane was nearing the end of the runway, the pilot aborted the takeoff, and the airplane landed just beyond the departure end of the runway and into dirt. The airplane slid on its belly and subsequently collided with an airport fence. The wings were substantially damaged, and a postimpact fire ensued. Postaccident examination revealed extensive thermal damage throughout the engine. All engine accessories and the propeller hub remained attached to the engine. All engine accessories were removed along with the upper spark plugs and rocker box covers. The crankshaft was rotated by hand using the propeller. Thumb compression and suction was obtained on all six cylinders. The intake and exhaust valve rocker arms on all cylinders exhibited equal movement when the crankshaft was rotated. The turbo-charger waste gate remained attached in its installed position. The butterfly valve was in the open position. The control arm was actuated using a hand tool, and the butterfly valve opened once pressure was released. The turbine and compressor impellers spun freely by hand with no binding noted. The compressor and turbine impellers were intact with slight lateral play in the shaft between the compressor and turbine impellers along with slight rub marks on the housing. No preaccident mechanical failures or malfunctions were found that would have precluded normal operation of the engine.

Probable Cause and Findings

The pilot’s delayed decision to abort the takeoff due to insufficient airspeed.

 

Source: NTSB Aviation Accident Database

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