WPR15LA165 · Raytheon Aircraft Company B200 UNDESIGNAT

The commercial pilot reported that, about 10 minutes after takeoff for a cross-country flight, the airplane experienced a loss of electrical power and that he lost contact with air traffic control (ATC). The pilot proceeded on a westerly course and then proceeded southbound. Partial electrical power was restored, and he tried to re-establish radio contact with ATC with no success. The pilot subsequently diverted to an airport for landing. After he received a green light signal from control tower personnel, the pilot extended the landing gear and flaps. When the airplane touched down, the pilot realized that the landing gear had not extended.

During initial postaccident interviews, the pilot stated that, when he departed, the generators were on and that, after the loss of electrical power, he did not perform any emergency procedures or attempt to reset the generators because the checklist was in a cabinet that he could not reach. In a subsequent interview, the pilot stated that he may have accidently turned on the starter switches while on the ground at the departure airport, which would have turned off the generators and led to the loss of electrical power.

After the accident, a mechanic entered the cockpit, and he reported that he found the landing gear handle in the "down" position and the flap handle in the "full-up" position. The battery switch was in the "off" position with the battery gang bar down, which turned off the battery, generator 1, and generator 2. After lifting the gang bar and turning on the battery switch, he saw nothing on the cockpit displays but heard the airplane power up. After about 30 minutes, he turned on the electrical power, and the cockpit displays illuminated, and he heard the landing gear trying to extend.

During recovery, the airplane was lifted off the ground, and the landing gear were successfully extended to the down-and-locked position using the emergency gear extension hand pump.

It is likely that the pilot inadvertently turned on the starter switches, which turned off the generators, at the departure airport, and that this led to the depletion of the battery and loss of electrical power to the airplane's systems. If the pilot had the emergency checklist available and followed the emergency procedures for a loss of electrical power, which required resetting the generators, or if he had attempted to manually extend the landing gear, he likely could have lowered the landing gear.

Verbatim NTSB analysis and probable cause from the NTSB dataset