N299AVRaytheon Aircraft B200 · 1999

On March 12, 2024, at 0805 mountain daylight time, a Raytheon Aircraft Company B200 King Air airplane, N299AV, was substantially damaged when it was involved in an accident near Billings, Montana. The pilot and safety pilot were not injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 positioning flight.

The pilot stated that he flew the airplane for 5.8 hours the day before the accident. On the morning of the accident, he planned to depart Billings Logan International Airport (BIL), Billings, Montana, for a short, 17-minute trip to pick up passengers at 0800 at Colstrip Airport (M46), Colstrip, Montana. The pilot recalled that he did not feel hurried and had plenty of time.

After departure from BIL, he received a "RA Fail" message (indicating a radio altimeter failure), followed by a "PT Fail" amber light (indicating pitch trim failure) on the primary and multi-function displays, and the electrical panels began to shut down. The pilot and safety pilot both recognized that the airplane had a total loss of electrical power.

The pilot began a descending turn to return to BIL. As the airplane was descending and heading back to the airport, the safety pilot searched for an electrical failure checklist. He could not find such a checklist and the safety pilot started reading out the checklist for manually extending the landing gear. The BIL airport traffic control tower controller cleared the pilot to land by using a green light gun signal. The pilot opted to enter the airport traffic pattern on an extended base leg and land on runway 28R. He pulled the landing gear circuit breaker on the base leg and unstowed the emergency landing gear extension bar. After pumping it for about 30 pumps (he estimated this took about a minute), he turned the airplane from the base leg to final approach and felt pressure on the landing gear extension bar handle. Both pilots observed that the main landing gear was extended by looking out the windows but were unable to verify the landing gear were in the down-and-locked position because there was no electrical power to illuminate the landing gear indicator lights.

With the flaps retracted, the airplane touched down on runway 28R. The pilot stated that the main landing gear buckled, followed by the nose landing gear. The propellers contacted the runway as the belly slid across the surface, damaging both engines.

When asked if he reset the generators while in flight, the pilot could not remember. Additionally, when asked to describe the switch that he would use to perform a generator reset, he stated they were the silver switches (without a gang bar) that are pressed down to reset the generators. He further stated that switches under the gang bar were only used for starting the engines.

Investigators reviewed FAA-provided ADS-B data for the accident flight (see figure 1). The data disclosed that the airplane departed from runway 28R about 0742 and made a gradual, climbing, right turn to the east. The track ended about 0747.

Figure 1. Accident flightpath.

According to FAA airman records, the pilot had accrued 186 hours as pilot-in-command of the same make and model as the accident airplane. According to operator records, between October 1, 2023, and the date of the accident, the pilot had accumulated a total of 146 flight hours, of which 32.7 hours were in the accident airplane. The pilot’s most recent medical certificate was issued with the limitation that he must use corrective lenses.

The pilot completed his most recent Part 135 recurrent training in a Beechcraft King Air 200 equipped with a G1000 avionics suite on October 19, 2023. The training, conducted over three days, included a satisfactory completion of the 14 CFR 135.293(a)(2-3) (knowledge test on topics including aircraft systems and emergency procedures) and 135.297 (instrument proficiency) checks. The pilot completed 6 hours of simulator flight, during which he performed 10 takeoffs and 7 landings. Emergency procedures included a simulated landing gear and flap-system malfunction. The curriculum also included 11 hours of ground training and 4.5 hours of briefing and debriefing.

The pilot had previously completed his initial King Air 200 training on November 1, 2022, which included 40.5 hours of ground instruction and 11.5 hours of flight training.

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 a complete electrical power loss, which rendered the gear position indicator lights inoperative.

A review of the airplane’s records revealed that it was purchased by the operator in February 2006. The hour meter time was 8,712.4 hours.

The battery was installed new in June 2020 and, according to maintenance records, had been removed on four occasions for servicing. It was last serviced on October 18, 2023, about 5 months before the accident, at an airplane total time of 13,741.1 hours, when it was recorded as being reconditioned and had a capacity of 93.90%.

Engine Start

According to the airplane’s checklist in the Pilot’s Operating Handbook (POH), the battery engine start procedure begins with the right ignition and engine start switch selected to the “ON” position. When the right engine reaches 12% N1 (compressor speed) or greater, the right condition lever is placed to “LOW IDLE.” The pilot is instructed to monitor right ITT (inlet turbine temperature) and N1, with a limitation of 1,000°C maximum ITT, and to verify right oil pressure. At 50% N1 or greater, the right ignition and engine start switch should be turned “OFF” and the right condition lever advanced to “HIGH IDLE.” The right generator switch must then be placed into the “GEN RESET” position and then placed “ON.” The pilot should then verify that the battery charge annunciator light is illuminated until the loadmeter reads 50% or less (the illumination should occur about 6 seconds after the generator comes online).

The same procedure is then conducted on the left engine. The left ignition and engine start switch is selected “ON” and then, when 12% N1 or greater is reached, the left condition lever is placed to “LOW IDLE.” At 50% N1 or greater, the left ignition and engine start switch is selected to “OFF.” The pilot is instructed to check DC voltage and loadmeters by pressing to verify a reading between 27.5 and 29.0 volts. The left generator must then be placed into the “GEN RESET” position and then placed “ON.” Finally, the right condition lever is then reduced to “LOW IDLE.”

Starter/Generator System

Located on the pilot’s left subpanel, the battery switch (BATT) and the left and right generator switches (GEN 1 and GEN 2) are red-tipped, guarded toggle switches positioned beneath a gang bar fitted with a piano hinge (see figure 2). The purpose of the bar is to turn all three switches off at the same time by pressing down on the piece of metal. Generator switch positions are “GEN RESET–ON–OFF,” and the pilot must hold the switch in the “GEN RESET” position, where it is spring-loaded to return to “ON.” To bring a generator online, the switch is placed momentarily in the "GEN RESET" position, which allows the generator voltage to build up to 28 volts with the line contactor open. When the switch is released to the "ON" position, the line contactor closes, and the generator will go online. The POH notes, “In order to turn the generator ON, the generator control switch must first be held upward in the spring-loaded RESET position for a minimum of one second, then released to the ON position.”

Figure 2. Generator and starter switches.

Below the generator switches are the left and right ignition and engine start switches. The unguarded, metal toggle switches have the following positions: ON–OFF–STARTER ONLY. 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 starter circuit takes precedence over the generator circuit, preventing the generator from operating until the starter switch is turned off.

According to the POH, after a dual generator failure, there is about 30 minutes of battery life for a typical airplane. The POH notes, “This battery life is based on specific assumptions which may not occur in every instance such as the generator loads at the time of failure, battery condition, the time required to load shed non-essential equipment, and the electrical equipment installed on the airplane.”

Manual Landing Gear Extension

The POH instructs the pilot to unstow and pump the alternate extension handle to perform a manual gear extension. It states that “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.” There is no pressure quantified or time duration stated for what the pilot should expect to successfully extend the gear to the down-and-locked position.

A review of the airplane’s records revealed that it was purchased by the operator in February 2006. The hour meter time was 8,712.4 hours.

The battery was installed new in June 2020 and, according to maintenance records, had been removed on four occasions for servicing. It was last serviced on October 18, 2023, about 5 months before the accident, at an airplane total time of 13,741.1 hours, when it was recorded as being reconditioned and had a capacity of 93.90%.

Engine Start

According to the airplane’s checklist in the Pilot’s Operating Handbook (POH), the battery engine start procedure begins with the right ignition and engine start switch selected to the “ON” position. When the right engine reaches 12% N1 (compressor speed) or greater, the right condition lever is placed to “LOW IDLE.” The pilot is instructed to monitor right ITT (inlet turbine temperature) and N1, with a limitation of 1,000°C maximum ITT, and to verify right oil pressure. At 50% N1 or greater, the right ignition and engine start switch should be turned “OFF” and the right condition lever advanced to “HIGH IDLE.” The right generator switch must then be placed into the “GEN RESET” position and then placed “ON.” The pilot should then verify that the battery charge annunciator light is illuminated until the loadmeter reads 50% or less (the illumination should occur about 6 seconds after the generator comes online).

The same procedure is then conducted on the left engine. The left ignition and engine start switch is selected “ON” and then, when 12% N1 or greater is reached, the left condition lever is placed to “LOW IDLE.” At 50% N1 or greater, the left ignition and engine start switch is selected to “OFF.” The pilot is instructed to check DC voltage and loadmeters by pressing to verify a reading between 27.5 and 29.0 volts. The left generator must then be placed into the “GEN RESET” position and then placed “ON.” Finally, the right condition lever is then reduced to “LOW IDLE.”

Starter/Generator System

Located on the pilot’s left subpanel, the battery switch (BATT) and the left and right generator switches (GEN 1 and GEN 2) are red-tipped, guarded toggle switches positioned beneath a gang bar fitted with a piano hinge (see figure 2). The purpose of the bar is to turn all three switches off at the same time by pressing down on the piece of metal. Generator switch positions are “GEN RESET–ON–OFF,” and the pilot must hold the switch in the “GEN RESET” position, where it is spring-loaded to return to “ON.” To bring a generator online, the switch is placed momentarily in the "GEN RESET" position, which allows the generator voltage to build up to 28 volts with the line contactor open. When the switch is released to the "ON" position, the line contactor closes, and the generator will go online. The POH notes, “In order to turn the generator ON, the generator control switch must first be held upward in the spring-loaded RESET position for a minimum of one second, then released to the ON position.”

Figure 2. Generator and starter switches.

Below the generator switches are the left and right ignition and engine start switches. The unguarded, metal toggle switches have the following positions: ON–OFF–STARTER ONLY. 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 starter circuit takes precedence over the generator circuit, preventing the generator from operating until the starter switch is turned off.

According to the POH, after a dual generator failure, there is about 30 minutes of battery life for a typical airplane. The POH notes, “This battery life is based on specific assumptions which may not occur in every instance such as the generator loads at the time of failure, battery condition, the time required to load shed non-essential equipment, and the electrical equipment installed on the airplane.”

Manual Landing Gear Extension

The POH instructs the pilot to unstow and pump the alternate extension handle to perform a manual gear extension. It states that “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.” There is no pressure quantified or time duration stated for what the pilot should expect to successfully extend the gear to the down-and-locked position.

A search of the NTSB accident database revealed that accidents involving similar circumstances have occurred in the same make/model as the accident airplane on at least three occasions:

· November 2021 (WPR22LA063): Probable cause was the pilot’s improper checklist use, which resulted in an electrical malfunction and subsequent gear up landing.

· May 2015 (WPR15LA165): Probable cause was the pilot's inadvertently turning on the starter switches, which turned off the generators and resulted in a loss of electrical power and gear-up landing. Contributing to the accident was the pilot's failure to follow the emergency procedures for a loss of electrical power or to manually extend the landing gear.

· April 2000 (SEA00LA066): Probable cause was the pilot's failure to properly follow pre-takeoff checklists (resulting in the engine starters remaining engaged after engine start, generators not being activated, discharge of the aircraft battery and consequent total electrical failure during flight with associated disabling of normal landing gear extension capability), and his subsequent failure to properly perform a manual landing gear extension resulting in a landing with the gear not down-and-locked. Factors included: the pilot's lack of experience in type, steps not listed in the manufacturer's Airplane Flight Manual (AFM) GENERATOR INOPERATIVE procedure, conditions not listed in the manufacturer's AFM MANUAL LANDING GEAR EXTENSION procedure; and the FAA's inadequate approval of both of these procedures.

A review of the Aviation Safety Reporting System database revealed the following similar instances:

· February 2023 (ACN 1975037): A loss of electrical power because the engine starter system was found to be on the incorrect setting, which overrode the generators.

· September 2013 (ACN 1120983): An electrical failure because the generators were never turned on after the crew started the engines with a ground power cart.

· September 2013 (ACN 1119624): An electrical failure because the pilot unintentionally activated the starters, removing the generators.

· October 2006 (ACN 713207): A loss of electrical power due to the failure to reset the generator switches.

The airplane was equipped with a Garmin G1000 avionics system that recorded flight data information. A review of the data disclosed that the electrical system was powered on at 0617:58 for 7 minutes, consistent with the flight crew entering the flight plan in the system. The system was again powered on at 0629:03 with one engine torque starting at 0633:20; the other engine was started at 0636:17. The airplane started taxiing at 0638:14 and began its departure roll at 0642:32. The data ended at 0647:05.

Engine Start

When asked to explain the engine start-up procedures he used for the accident flight, the pilot stated that he started the left engine first and waited about 7-8 seconds for N1 to stabilize before he brought the condition lever up to high idle (about 52%). He recalled that he then positioned the three-setting switch down to change from “starter to generator.” He verified that both volt meters indicated loads below 50% and then started the right engine with a cross-generator start. After start, he verified that the battery indicated 23 volts. He could not provide specifics of the positions of the “Ignition and Engine Start” switches or the generator switches, but he stated that it was a normal start. He did not perform an engine run-up, as it was not part of his procedures.

Postaccident Examination

Postaccident examination of the airplane revealed that the master battery switch was in the “OFF” position, and both generator switches were in the “ON” position. The starter switches were “OFF.”

The caution-advisory annunciator panel was documented without power applied. The “L DC GEN” light was removed and found to have a small white piece of debris between the light housing and the metal rack. The debris was consistent in shape and color with a piece of thin wire casing with a single strand of wire embedded within it. Removal of the light bulbs revealed that one had a broken filament; the condition of the other bulb’s filament could not be determined. The housing was reinserted with the debris removed. The “R DC GEN” light was removed, and the lights were found to have broken filaments.

The battery was then connected to the airplane, and the battery switch was placed in the “ON” position. The annunciator panel test switch was activated, illuminating the lights on the warning annunciator panel; all the lights on the caution-advisory annunciation panel illuminated except for the left and right generator lights (“L DC GEN” and “R DC GEN”; see figure 3). When the left generator light was reset, the light dimly illuminated, consistent with one bulb not working. Another light was removed and placed into the receptacle for the left and right generator lights. When the annunciator panel was tested again, the left generator lights illuminated but the right did not illuminate.

Figure 3. Caution-advisory annunciation panel.

The airplane’s 28-volt, lead-acid main battery was found disconnected from the power supply. Using a multimeter, the battery had a voltage of 24 volts. The battery was capacity-tested by applying an electrical load of 42 amps, and the battery voltage dropped to 22.2 volts after 30 seconds, to 21.3 volts after 6 minutes, and it failed at 19.99 volts after 8 minutes, 12 seconds. The mechanic testing the battery stated normal batteries would indicate between 23.8 and 24.2 volts after 30 seconds.

After placing the airplane on jacks, investigators cycled the landing gear both manually and electrically and found the landing gear extension systems to function normally. To manually extend the landing gear, it took about 70-80 pumps on the emergency handle (about 1-1.5 minutes) before the landing gear extended to a locked position.