Beech 95B55 N678DM accident near Wilmington, Delaware

Probable cause

The pilots’ failure to place the left fuel selector into the proper position, which resulted in a total loss of the left engine’s power due to fuel starvation. Contributing was their failure to properly secure the left engine and their failure to maintain control of the airplane during the attempt to return to the airport.

NTSB analysis

The pilot and the flight instructor were departing the airport. Shortly after takeoff, the pilot requested to return to the airport but did not state a reason for returning or declare an emergency. The tower controller cleared the airplane to land on any runway, provided the current wind information, and attempted to contact the pilot but received no response. A witness then observed the airplane in a nose low attitude as it descended into the trees below. The airplane impacted trees and terrain about 2 nautical miles from the airport and came to rest inverted in a nose-low attitude. The airplane sustained substantial damage to the wings, fuselage, and tail. Examination of the airframe, flight controls, engines, and engine accessories revealed no evidence of preimpact failures or malfunctions that would have precluded normal operation.

The right fuel selector was found in the “main” position, while the left fuel selector was observed between the “main” and “crossfeed” positions. Both fuel selector valves were removed from the airplane, and air was blown through the valves to determine position. The right fuel selector valve was confirmed on the main (right) tank. The left fuel selector valve had no airflow when air was introduced through the crossfeed port. When air was blown through the main port, the airflow was restricted due to the position of the valve. Further, fuel was drained from the right fuel strainer and tested; no water was detected. No fuel was observed in the left fuel strainer. All fuel caps were observed closed and secured. The four fuel tanks were breached, and no fuel was observed. Based on this information, it is likely that during the flight one of the pilots inadvertently placed the valve between main and crossfeed positions. The fuel flow to the left engine was then restricted due to the intermediate position of the left fuel selector valve, which resulted in a loss of engine power.

Additionally, examination of the airplane revealed that, for both engines, the throttles were found full forward, the mixture controls were set to rich, and the propeller controls were set to high rpm settings, which indicated that the pilots did not attempt to secure the left engine as described in the emergency checklist for engine failure after liftoff and in flight in the pilot operating handbook for the airplane make/model. Following the loss of engine power to the left engine, the airplane’s performance and handling characteristics would have been significantly degraded, and it is likely that the pilots lost control of the airplane while attempting to return to the airport.

Postaccident toxicological testing of samples from the commercial pilot detected therapeutic levels of sertraline in his system. There was no evidence available to suggest that the use of this drug or any underlying condition that prompted the pilot’s use of it impacted his psychomotor performance during the flight.

Text from the NTSB. Open the NTSB docket for ERA19FA250 for the full record.