Story ID: 004
Accidents: September 2020
By: David Jack Kenny
Caption: Preliminary and final reports
Word Count: 1690
Preliminary Reports
Astra Damaged in Rejected Takeoff

IAI 1125 Astra SP, April 24, 2020, Fort Lauderdale, Florida – No injuries resulted when the Venezuelan-registered corporate jet overran the departure end of Fort Lauderdale Executive’s Runway 27 following an apparent loss of elevator authority. The pilot reported that the airplane did not respond when he pulled back the yoke at rotation speed. After a second unsuccessful attempt at 130 knots, he applied maximum braking and full reverse thrust. The jet passed through the runway overrun into the grass, pivoting left and collapsing nose and right main landing gear before coming to a stop.

Erosion Barrier Brings Down Helicopter

Eurocopter MBB BK117, July 4, 2020, Wooster, Ohio – As it began its takeoff run, the air ambulance’s rotor wash dislodged a poorly secured silt fence obscured by tall grass adjacent to the ramp. The fence blew into the main and tail rotor systems, requiring the crew to make a forced landing that caused substantial damage to the fuselage, tail boom, and tail rotor blades. There were no injuries to either pilot or either of the medical crew. The fence’s presence was not disclosed by notam or any other publication available to the pilots.
Final Reports
Lack of Recurrent Training Cited in Virginia State Police Crash

Bell 407, August 12, 2017, Charlottesville, Virginia – Training records suggest that the pilot of the Virginia State Police (VSP) helicopter that crashed while monitoring political demonstrations had not received any recurrent training in recovery from vortex ring state during his 16 years in the VSP aviation unit.  The pilot and observer were killed when the helicopter struck trees at a high descent rate and low forward speed while rapidly spinning clockwise, which the NTSB attributed to its having entered vortex ring state; lack of recent practice in recovery techniques was cited as a contributing factor.  The uncontrolled right yaw coincided with a sudden increase from 54 percent to 104 percent torque, but whether the increase in power preceded or followed initiation of the descent could not be determined.

The helicopter was initially dispatched to provide the VSP command center with a video downlink of the “Unite the Right Rally” and counterdemonstrations. After about 40 minutes, it was reassigned to accompany the governor’s motorcade. Five minutes after joining the motorcade at an altitude of approximately 1,500 feet agl, the helicopter veered right and began descending. FAA radar data showed it descending through 750 feet agl at 6,800 fpm with a groundspeed of 30 knots.  A combination of security camera footage and witness accounts suggest that the aircraft initially came to a hover, then “entered a rolling oscillation, began to spin about its vertical axis, and descended in a 45-degree nose-down attitude while continuing to spin.” The crew of a Fairfax County Police Department helicopter witnessed the crash and landed nearby, but was unable to reach the VSP crew due to heavy black smoke and fire.

The NTSB’s probable cause report published on July 13 describes vortex ring state, also known as settling with power, as “…an aerodynamic condition that occurs when the helicopter descends at the downward speed of its own vortex wake. The vortex system accumulates, building in strength and producing increased downwash through the main rotor. The rotor, operating in a high downwash field, is unable to arrest the helicopter’s descent rate, even with increased collective.” Recovery can be safely practiced at altitude. The 48-year-old, 5,830-hour pilot had nearly 800 hours in type and had served as commander of the VSP aviation unit since December 2012.  He held numerous flight instructor ratings including helicopter and instrument helicopter, so was necessarily familiar with vortex ring state. However, his training records since 2001 showed no evidence of his having practiced recoveries in the accident make and model, and the VSP aviation unit’s training manual classified this maneuver as optional.

Tasmanian Crash Caused By Inappropriate Emergency Drill

Eurocopter AS350BA, November 7, 2017, Hobart, Tasmania, Australia – In a final report published on July 20, the Australian Transport Safety Bureau determined that the 1,200-hour commercial pilot receiving transition training failed to follow the procedure prescribed by the AS350 rotorcraft flight manual (RFM) during a simulated hydraulic failure, leading to a catastrophic loss of control. Rather than continuing into a low-speed run-on landing, he attempted to enter a high hover contrary to the explicit warning in the RFM’s Emergency Procedures section: “DO NOT ATTEMPT TO CARRY OUT HOVER FLIGHT OR ANY LOW SPEED MANEUVER.” The operator’s chief flight instructor was killed and the pilot receiving instruction seriously injured when the aircraft pitched forward, rolled 80 degrees left, and crashed onto the front left side of the cabin. The ATSB also faulted the instructor for not conducting a preflight briefing to review the details of the simulated emergency procedure ahead of time.

The operator’s technique for simulating a hydraulic failure was found to be the one commonly used before the 2003 publication of Supplement 7 to the RFM: the instructor initially depressed the HYD TEST button to make the hydraulic circuit bypass the main rotor servo actuators. After slowing the helicopter to a safety speed of 40 to 60 knots, the student then activated the HYD CUTOFF switch to depressurize the servos before the HYD TEST button was released. Supplement 7 calls for releasing the HYD TEST button before the HYD CUTOFF switch is engaged so that a single switch can restore hydraulic pressure at any point in the maneuver. This might take up to three seconds when the switch functions normally. The accident helicopter’s switch “had a level of wear, corrosion, contamination, and internal damage.” However, there were no reports of it having malfunctioned before the accident.

TAWS Disabled During Fatal Low-Altitude Night Flight

Bell 206, November 3, 2018, Uvalde, Texas – TAWS on the helicopter that hit a hillside 100 feet below its top was set to “inhibit” and an incorrect barometric pressure setting would have caused its altimeter to read 80 feet higher than its actual altitude. The 76-year-old pilot, a Vietnam veteran with more than 23,400 hours of flight experience, was ferrying a newlywed couple from their reception at a private ranch to board an airline flight in San Antonio. All three were killed when the helicopter crashed less than five miles from its point of departure.

The accident occurred shortly before midnight. Sky conditions were reported to be clear and the pilot held an instrument helicopter rating, but data downloaded from the helicopter’s primary and multifunction displays indicate that it never climbed above 1,900 feet msl before beginning a gradual descent.  The debris path stretched about 100 yards at an elevation of 1,400 feet msl.  There was no evidence of any mechanical anomaly before impact.

Photographs from the reception show the helicopter bathed in bright floodlights before the passengers boarded. The NTSB’s probable cause report, published on May 19, notes that the pilot had previously reported a diagnosis of early cataracts, but could not determine the extent to which either might have compromised his night vision.

Overlooked Fuel Order Caused Double Engine Flameout

Beechcraft B200, April 24, 2019, Gillam Airport, Manitoba, Canada – A combination of difficulty locating line crewmen, a delayed departure, and the exchange of piloting assignments resulted in the air ambulance departing without loading the fuel assumed in the pilots’ flight-planning calculations. The King Air subsequently touched down on the frozen surface of Stephens Lake while attempting to divert to Manitoba Gillam Airport after the left engine flamed out at FL250. The airplane rolled onto the shore and came to rest 190 feet from the threshold to Runway 23, shearing off the lower sections of both main gear legs but causing no injuries to the two pilots or two flight nurses on board. The accident occurred during a positioning flight from Winnipeg to Churchill en route to its base at Nunavut’s Rankin Island Airport. 

The flight crew consisted of a line indoctrination captain and a candidate training for upgrade to captain. According to the Transportation Safety Board’s July 27 final report, they were unable to find a lineman to refuel the airplane after arriving the day before. Maintenance staff replaced the right engine’s fuel nozzles and performed the required engine runs before the crew returned for duty at 3:00 p.m. The candidate would serve as captain and the senior captain as first officer (FO) on the return flight. They calculated that the flight to destination, diversion to alternate, and additional 45-minute reserve required by the Canadian Aviation Regulations would require 2,465 pounds of fuel. During his preflight inspection, the FO determined that about 1,600 pounds was already on board and went to the FBO’s fuel office, but found no one there to take the order.

After the delayed arrival of one flight nurse, the FO confirmed that the airplane was ready for flight and the crew boarded. The captain replied to the FUEL QUANTITY item on the after-start checklist with the printed entry of “SUFFICIENT/BALANCED” without checking the gauges. One hour and 34 minutes into the flight, the left engine’s fuel pressure warning light illuminated and the engine began to surge.  Noticing that the fuel gauges read zero pounds, the captain asked about their fuel status, and the FO realized that he’d forgotten to return to the FBO office to order more.

The crew declared an emergency and requested a diversion to Gillam. The left engine stopped two minutes later and the crew performed the emergency engine shutdown procedure, but the propeller would not feather. The captain reduced power on the right engine and for the next three minutes they descended through the clouds at 3,000 to 6,000 fpm while turning right toward the extended centerline of Runway 23. The crew initially extended the landing gear, but retracted it again when the airplane dropped below the Vnav descent profile. The left engine stopped windmilling at an altitude of 2,800 feet msl. They broke out and made visual contact with the runway at 2,000 feet.  The right engine lost power at 835 feet above ground level. The crew shut it down, feathered the propeller, and again extended the landing gear 50 feet above the surface.