Beech A35 N580B accident near Hesperia, California

Probable cause

The pilot's failure to maintain airplane control during an attempted return to the airport following the separation of the spinner bulkhead during takeoff as a result of fatigue cracking. Contributing to the accident was the pilot's improper decision to fly an unairworthy airplane.

NTSB analysis

The pilot was conducting a personal flight; witnesses reported that the takeoff and initial climb appeared normal, however something came off the airplane near the end of the runway. The airplane climbed to about 800 ft before the nose dropped and it made a "radical left turn." After the turn, the wings appeared vertical and the airplane lost about 400 ft. The airplane leveled out and appeared to be going back toward the airport, however the nose remained low. The airplane turned right and appeared to align with a road. The airplane then struck powerlines that were parallel to the road, impacted the ground, caught on fire, and came to rest inverted. The mechanic who worked on the airplane the day before the accident, reported that the airplane had quite a few maintenance issues; he completed a few maintenance items that the pilot wanted fixed. However, the mechanic indicated to the pilot that he shouldn't fly the airplane until the remaining work could be completed.

The pilot purchased the airplane less than a year before the accident. The airplane's most recent maintenance logbook entries were inconsistent and contained date corrections. In addition, there was a 6-7 year gap between the most recent logbook entries with about 27 hours recorded on the tachometer during that time.

Wreckage documentation revealed that several pieces of the spinner and spinner bulkhead had separated shortly after takeoff and were found on the departure end of the runway. Some of the screws remained attached to the spinner and were undamaged, however, a majority of the screw holes were ripped. Metallurgical examination revealed that the fractures across the rivets and rivet holes were consistent with progressive fatigue crack growth.

However, postaccident examination of the airframe and engine revealed no other anomalies that would have precluded normal operation. Damage signatures to the propeller blades were consistent with the engine producing power at the time of impact and it appears that the pilot should have been able to maintain sufficient altitude and airplane control to return to the airport.

Further, the pilot was likely attempting to return to the airport when he abruptly reversed course and lost excessive altitude that resulted in the collision with the powerline. Because the maintenance on the airplane had not been completed yet by the mechanic, the pilot's decision to fly an unairworthy airplane was improper.

Whether the pilot's underlying medical conditions or effects from his use of tramadol, an opioid, and meprobamate, a tranquilizer, both impairing substances, contributed to his unsafe decision-making, could not be determined.

Text from the NTSB. Open the NTSB docket for WPR18FA171 for the full record.