Preliminary Reports
No Injuries in King Air Gear Collapse
Raytheon B200, March 12, 2024, Billings, Montana
Neither pilot was injured when the gear collapsed during an emergency landing following a total loss of electrical power. The Part 91 positioning flight departed Billings shortly before 08:00 local time on a planned 17-minute trip to pick up passengers at Colstrip, Montana. The starting and departure sequences appeared normal, but shortly after takeoff a cascade of annunciator warnings alerted the pilots to “a total loss of electrical power.”
The safety pilot found no electrical failure checklist in the flight manual and instead began the checklist for manual gear extension. The flight returned to Billings and was cleared to land via light signals. The pilot entered the pattern on an extended base leg, pulled the landing gear circuit breaker, and “unstowed the emergency landing extension bar,” using it to pump the gear down “about 30 times.” Without electrical power, the gear position indicators were inoperative. The King Air touched down with flaps retracted; in the pilot’s words, “the main landing gear buckled, followed by the nose gear,” and both propellers struck the runway.
Investigators found the generator switches in the “ON” position but the battery master turned “OFF.” The pilot could not recall whether he’d tried resetting the generators but described the procedure incorrectly, referring to the engine start switches rather than the generator controls. Further testing found both generator caution lights on the annunciator panel inoperative. The battery initially produced 24 volts, which dropped rapidly under load testing. Tests with the airplane on jacks also showed that manual extension required 70-80 pumps of the emergency handle to extend and lock the landing gear.
Three Fatalities in Heli-ski Accident
Eurocopter AS350B3, April 2, 2024, Valais, Switzerland
Three occupants of the helicopter were killed and the other three evacuated with injuries after their heli-ski flight “skidded off” its landing zone around the 12,000-foot level of the north side of Petit Combin mountain. Initial reports indicated that the fatalities included the pilot, an American ski guide, and one passenger of undisclosed nationality.
Seven rescue aircraft responded to the scene. The survivors were reported to be three brothers from the UK, one of whom pushed the others out of the cabin as the helicopter skidded down the mountain.
Final Reports
Emergency Brake Failure Cited in CJ3 Excursion
Cessna 525B, March 7, 2022, Middle River, Maryland
The aircraft was substantially damaged after it departed the runway on landing at Martin State Airport and ran into the perimeter fence. Neither of the pilots aboard the Executive Flight Services Part 135 charter flight were injured.
Flying a positioning flight from Washington Dulles International Airport, the pilots reported that they were flying a stabilized approach to Runway 15 at Martin State. Adding 5 knots to the Vref speed to account for gusting wind, the pilots said they determined that they would need about 3,000 feet of the 6,997-foot runway to land.
The aircraft landed within the touchdown zone, they reported, and said the rollout appeared normal until the pilot asked, “Why aren’t the brakes working?” The copilot applied brakes on his side but also was unsuccessful in achieving sufficient braking.
Then they attempted to locate the emergency brake, which is located under the instrument panel in front of the pilot’s legs, but were unable to find it. Instead, they used the parking brake. The airplane continued past the runway at about 58 knots, traveling 450 feet before impacting the perimeter fence.
ADS-B data and video footage from airport surveillance cameras indicate that the aircraft touched down about 2,000 feet beyond the approach end of the runway at about 110 knots.
An examination of the Citation CJ3's braking system failed to find an anomaly, but a performance study of the accident aircraft revealed that it had decelerated on the ground primarily by way of aerodynamic drag, free rolling with “unbraked” wheel friction for about 5,000 feet after touchdown. “There was virtually no evidence of deceleration due to hydraulic or pneumatic wheel braking during the rollout,” the NTSB said, concluding that the probable cause was an “undetermined failure of the brake system.”
Contributing to the accident, the Safety Board added, was the inability of the pilots to locate and operate the emergency brake control.
At the time of the accident, the pilot had 2,789 hours total time—248 hours in make and model, and 1,151 hours as pilot-in-command (PIC). The copilot had 7,505 hours total, 115 in make and model, and 5,933 as a PIC. Visual conditions prevailed at the time of the accident with 10 miles visibility and wind speeds of 12 knots gusting to 21 knots. The 2009 model aircraft had 3,669 hours when it had the excursion, and its last inspection had been three months earlier.
Stack Height, Paint Cited in Idaho Freighter Crash
Cessna 208B, April 13, 2022, Heyburn, Idaho
The operator of a potato processing plant beneath the final approach course to Runway 20 of the Burley (Idaho) Municipal Airport failed to complete the mitigation measures required after the FAA determined that the plant’s vent stacks posed a hazard to aerial navigation. The solo 30-year-old commercial pilot was killed when her Caravan struck an agglomerate stack whose top was just 98 feet below the 3.5-degree glidepath to the runway’s displaced threshold. The plant operator had fitted that stack and five of six other stacks grouped together with flashing red lights but had not painted them in alternating stripes of white and aviation orange, as directed.
The Part 135 freight flight originated in Salt Lake City. The accident occurred during the second RNAV approach to Runway 20. The first leveled off about 20 feet above the runway before the pilot initiated a missed approach, presumably after evaluating landing conditions in accordance with company policy and procedures.
On the second approach, the Caravan descended about 130 feet below the glidepath on short final, entering and emerging from clouds of steam from the other six stacks before striking the agglomerate stack. While the agglomerate stack was clearly visible from the ground throughout, an NTSB performance study found that for most of the last 30 seconds before impact, it would have been obscured by the airplane’s instrument panel while the runway threshold remained visible.
Prevailing weather included winds from 210 degrees at 8 knots and one mile visibility below a 2,300-foot broken layer with a temperature of -3 C and a dew point of -5. Although temperatures were below freezing and visible moisture was present in the steam clouds emitted from the plant, investigators who arrived within hours found no structural icing on the airframe, and there was no evidence of any pre--impact anomaly of airframe, instrumentation, or powerplant.
The 1,380-hour pilot had flown into Burley at least 13 times in the preceding year. She had logged 213.5 hours in the last 90 days and 85.9 in the past 30 days, and flown 193 hours in the Caravan.
Loose Fasteners Caused Drastic Loss of Control
Cessna 560, Jan. 27, 2023, Buffalo, New York
A nearly catastrophic departure from controlled flight was traced to maintenance personnel’s deviation from their usual reinstallation procedure of the engine cowling after performing maintenance. The twin-engine jet lost nearly 20,000 feet in less than six minutes after the left engine’s cowlings detached from the nacelle at 23,000 feet, striking the fuselage and horizontal stabilizer.
The drastic increase in parasite drag triggered an uncommanded left roll and yaw, causing the rapid descent. The pilots declared an emergency and eventually recovered control 3,200 feet above Lake Erie. Though airplane control remained difficult, they made a successful emergency landing at New York’s Buffalo Niagara International Airport. One passenger suffered serious injuries in the upset; the other two passengers and both pilots sustained minor injuries.
The charter flight from Toronto to Fort Lauderdale, Florida was made the day after a maintenance stop at the operator’s base to troubleshoot discrepant fuel flow indications from the left engine and an intermittent indication of low hydraulic pressure after landing. A daily inspection was also conducted. Interviews with the maintenance technicians found that a disruption of their usual sequence of tightening the cowling fasteners resulted in “the front inboard row of 6 consecutive fasteners” not having been secured.
Aircraft damage included a tear in the skin of the left side of the vertical stabilizer, dents to the left horizontal stabilizer and elevator, and multiple tears in the left horizontal stabilizer’s de-icing boot.
Unapproved “Gear Plates” Contributed to Dynamic Rollover
Bell 206 B3, July 1, 2023, Adolfström, Sweden
Oversized “gear plates” intended to prevent the helicopter’s skids from sinking into snow apparently caught the side rail of the “carriage” on which the helicopter was parked during an attempted liftoff, causing a dynamic rollover that destroyed the main rotor system. The 42-year-old 252-hour commercial pilot escaped unharmed.
The flight was intended to pick up passengers six minutes away. Examination of the carriage found damage to the side rail from contact with the rear gear plates after the helicopter slid right while preparing to take off. The gear plates were found to have been fabricated by the operator without the required approval by the EASA or any other regulatory authority.