Pilot Debrief

Raytheon Aircraft Company B200 near Billings, MT — 2024-03-12

Final reportWPR24LA109
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Date
2024-03-12
Location
Billings, MT, USA
Airport
BIL
Aircraft
Raytheon Aircraft Company B200
Registration
N299AV
Category
Airplane
Highest injury
None
Fatalities
0

Probable cause

The pilot's improper engine start, resulting in the engine starters remaining engaged and the generators not being activated, which led to the discharge of the airplane’s battery and subsequent total electrical failure after takeoff. Contributing to the accident were generator caution lights not illuminating and the pilot’s inadequate manual landing gear extension, resulting in a landing with the gear not down and locked.

Contributing factors

Contributing to the accident were generator caution lights not illuminating and the pilot’s inadequate manual landing gear extension, resulting in a landing with the gear not down and locked.

NTSB narrative

The pilot stated that shortly after departure, the airplane lost all electrical power. While descending and returning to the airport, the pilot attempted to manually extend the landing gear but could not verify they were in the down-and-locked position because the landing gear indicator lights were not operational. With the flaps retracted, the airplane touched down on the runway and the landing gear collapsed. According to the airplane’s Pilot’s Operating Handbook (POH), the engine start procedure required sequencing to ignite the engine before placing each generator online. To turn the generator on, the generator control switch must first be held upward in the spring-loaded “GEN RESET” position for a minimum of one second, then released to the “ON” position. The electrical system is designed so that the starter circuit has priority over the generator circuit, prohibiting a generator from coming online until the starter is fully disengaged. Placing the ignition and engine start switch into any position except “OFF” results in the same-side generator shutting off, and it is not possible to bring the generator online until the ignition and engine start switch is moved to the “OFF” position. The POH also instructs the pilot to unstow and pump the alternate extension handle to perform a manual gear extension. It states, “If one or more green gear-down annunciators do not illuminate for any reason and a decision is made to land in this condition,” the pilot should continue pumping the handle “until maximum resistance is felt.” Postaccident examination of the airplane revealed that the generator caution lights were not operational and it is unlikely that the pilot tested them. Capacity testing of the battery indicated that its condition was slightly less than that of a normally functioning battery, which is likely partially the reason the battery lasted just 18 minutes after start, rather than the specified 30 minutes. Additionally, the 30-minute battery life assumes that only essential electrical equipment is operating. No mechanical anomalies were found during the postaccident manual extension of the landing gear. The pilot stated that, during training for emergency manual landing gear extension procedures, he consistently verified illumination of three green indicator lights, confirming that the landing gear was in the down-and-locked position. During the accident flight, he was unable to obtain this visual confirmation due to the complete electrical power loss, which rendered the gear position indicator lights inoperative. It is likely that the pilot inadvertently turned on the starter switches or did not reset the generators, which led to depletion of the battery and loss of electrical power to the airplane's systems. If the pilot had followed the emergency procedures and had continued to pump the manual landing gear extension handle, he likely could have lowered the landing gear.

NTSB coding

Evidence available

  • CVR
  • 8 docket documents
View NTSB final reportView NTSB docket

Docket documents8

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