Resource Hub Shutterstock/SingerGM Questionable maneuvering, faulty weather assessment leave two pilots seriously injured. It’s an aviation cliché, but sayings don’t become clichés without containing some morsel of broadly accepted truth: We deal with the weather that’s occurring, not the weather that was forecast. Forecasts aren’t exact and are as likely to be optimistic as pessimistic, so plans for a flight in conditions already expected to be difficult need to allow for the prospect that things could be even worse. Whether it’s rescheduling, rerouting, or just returning home while that’s still an option, the student-pilot lesson of “always give yourself a way out” never stops being relevant. The Mission At 9:35 am Pacific on Mar. 5, 2021, a Bell 212 crewed by two pilots lifted off from the Sechelt Aerodrome (CAP3) on British Columbia’s Sunshine Coast. The pilots’ destination was the staging area for a BC Hydro construction project about 21 nautical miles (nm) to the east in Cypress Provincial Park, where they were tasked with conducting several days of external-load operations supporting the construction of 230-kV transmission lines. Their planned route crossed the Howe Sound just north of Keats Island, then the Collingwood Channel and Bowen Island. The park is the site of a ski area, and terrain along the flight path is rugged, rising from sea level to 2,388-ft. Mount Gardner, the highest point at the southern end of a long mountain ridge on the west side of Bowen Island, then on to 4,714-ft. Mount Strachan and 4,016-ft. Black Mountain within the park itself. The Aircraft The Bell 212 is a twin-engine helicopter with a single two-blade, semirigid teetering main rotor powered by two Pratt & Whitney Canada PT6T-3B turboshaft engines. Each engine has an independent hydraulic system fed by an unpressurized reservoir mounted on the upper deck of the fuselage. Both systems provide boost assistance to the main-rotor flight controls, but only the No. 1 system boosts the antitorque pedals. A Bell 212 in standard configuration can seat up to 14 passengers and a single pilot. For this flight, all but the two pilot seats had been removed to increase cargo capacity. The helicopter had also received a factory modification boosting its 5-minute takeoff horsepower rating, making it a version commonly called the 212 HP. Additionally, in 2013 the 1973-model helicopter was fitted with a Boundary Layer Research Aerospace FastFin system, a modification that involved reshaping the original vertical stabilizer and adding two tail-boom strakes to improve the efficiency of the tail rotor and thereby simultaneously increase hover performance while reducing pilot workload. As of Mar. 5, the helicopter had flown a total of 29,220 hours. The Crew The operator’s revenue flights, including external loads, were normally flown by a single pilot. Two pilots were on board that day because the more senior, who served as pilot in command (PIC) on the ferry flight, planned to conduct a performance evaluation while the second pilot carried out the longline work. Both held commercial helicopter licenses and were highly experienced in the Bell 212, the local environment, and overall. The PIC, who was the company president and operations manager, had worked for the company for more than 20 years. He was also a Transport Canada–approved check pilot. His 9,125.5 hours of flight experience included 1,247 in the Bell 212, in which he had completed recurrent training exactly one year earlier. His initial mountain-flying training dated back to 2001, and he completed a refresher on Jan. 9, 2020. A pilot-proficiency check completed on Mar. 6, 2020, had covered abnormal and emergency procedures that included 180-degree and hovering autorotations, engine fires, and engine, governor, hydraulic, and tail-rotor failures. His colleague had 5,756.5 hours of documented flight experience, including 479.5 hours make-and-model. He had flown about six and a half years for the company. He obtained initial mountain-flying training in 2010 and completed a refresher course on Jan. 22, 2021, followed by general recurrent training on Feb. 19 and a pilot-proficiency check on Feb. 24, 2021. Both had taken their company’s crew resource management training on Oct. 26, 2020. Based on the pilots’ recorded work–rest schedules, the Transportation Safety Board of Canada (TSB) concluded that performance was probably not impaired by fatigue. The Weather On the morning of the accident, a low-pressure center just north of Vancouver Island was moving inland. With high pressure in the interior of British Columbia, the resulting steep pressure gradient produced gusty southeasterly winds. An associated cold front had been forecast to move through the vicinity of Bowen Island around 10 am. Moderate mechanical turbulence and low-level wind shear were anticipated below 3,000 ft., with turbulence expected to become severe in localized pockets. The area forecast issued by the Vancouver International Airport (CYVR) terminal called for ceilings at or above 6,000 ft. with good visibility and surface winds from 110 degrees at 18 kt., with gusts to 28 kt. Winds were forecast to ease to a steady 15 kt. after 11 am. The TSB report notes that the pilots spent considerable time reviewing not only forecasts but also current observations from stations along their planned route, some of which gave them cause for concern. The 9 am reading at Pam Rocks, a few miles north of their route, cited winds from 130 degrees at 32 kt. with gusts to 45. The station at Point Atkinson, just to the southwest, doesn’t measure gusts but reported sustained winds of 30 kt. from 110 degrees. The PIC also contacted the BC Hydro crew at the site for an update on conditions. While anticipating a rough ride, he decided to dispatch the flight in the expectation of improving conditions and a desire to keep the work on schedule. The Flight The helicopter initially established cruise flight between 2,300 and 2,600 ft. above sea level, encountering variable easterly to southeasterly winds and light turbulence. The PIC was in the right seat; his colleague, in the left seat, was the pilot flying (PF). Approaching Keats Island, they noticed “cat’s paws” waves produced by strong downdrafts on the surface of Howe Sound and discussed the prospect of increasing turbulence. The PF slowed the aircraft to 75-kt. airspeed and made a slight change of course to the north, but the pilots apparently didn’t consider climbing away from the ridge on Bowen Island and the mechanical turbulence that could be anticipated from strong southeasterly winds striking its face. Their cruising altitude of 2,600 ft. was only 212 ft. above the ridge’s highest point. Crossing Collingwood Channel at 2,560 ft., they encountered moderate turbulence and lost 130 ft. of altitude. Moments later, 2 nm west of the lee side of Bowen Island, the helicopter “violently pitched nose down and began a rapid right roll,” according to the TSB report, momentarily yanking the cyclic from the PF’s hand as the ship “rolled inverted, or close to inverted.” The PIC came on the controls to assist with the recovery as the PF applied full-aft cyclic. The helicopter dropped 1,400 ft. in just over 10 seconds, a rate of 8,220 ft. per minute. Loose items, including a spare headset, a handheld radio, a flight manual, and a lunch box, “launched forward from the rear cabin and struck the pilots on their helmets,” knocking the PF’s visor over his eyes. Several gauges broke loose from the instrument panel. The pilots regained some control 0.6 nm west of the coast of Bowen Island at about 1,400 ft. but found the flight controls extremely stiff. A caution light illuminated, indicating insufficient hydraulic pressure; in the chaos, neither pilot was able to see which hydraulic system had failed. They chose a large field on the island’s northwest corner as their emergency-landing site just before the No. 2 engine-out indicator lit up. Still 1.2 nm from their intended landing point and struggling with the controls as they descended through 900 ft., they picked out a closer spot to land. The PIC activated the emergency locator transmitter (ELT), and the PF made a Mayday call that was received by nearby aircraft but not by air traffic control. The pilots lost yaw control on final approach, and the helicopter began spinning to the right as it descended. The PF pulled both throttles to idle and raised collective to cushion the impact as they descended into the trees. The aircraft hit the ground and rolled inverted onto a rocky ledge about 270 ft. above sea level; ruptured fuel lines leaked Jet A onto the pilots. The PIC helped the PF free a foot pinned in the footwell, and they evacuated the cabin. Nearby residents responded to the scene and transported both to the hospital. The Investigation All the wreckage was found within an 80-ft. radius of the fuselage, confirming the helicopter’s near-vertical descent. The fuselage was three-quarters inverted in a steep, nose-low attitude. The tail boom was severed at its mounts and found uphill, pointed in the opposite direction. One main-rotor blade was broken off while the other was essentially intact. The tail-rotor drive shaft and its cover were severed 15 in. from their aft end, consistent with a main-rotor blade strike, and matching damage on the tail-rotor blades’ trailing edges and the vertical stabilizer confirmed the tail rotor was spinning freely at impact. The main-rotor mast showed deformation from “significant contact” with its static stops, indicative of mast bumping that stopped short of catastrophic separation. Both engines, their accessories, and the transmission were shipped to the manufacturer’s facility in Saint-Hubert, Québec, where all test runs were normal and no stored data indicated any in-flight anomaly. A teardown inspection of engine No. 2 confirmed it wasn’t running at impact. Pratt & Whitney Canada confirmed that if the helicopter rolled beyond 90 degrees toward inverted, unloading the main rotor and risking an overspeed, the engine governors would reduce or shut off fuel flow to bring main-rotor rpm back within limits. A roll beyond 90 degrees could also allow air to enter the hydraulic systems via their unpressurized reservoirs, resulting in degradation or loss of hydraulic boost to the flight controls. No anomalies were found in the hydraulic system’s pumps, filters, or fluids, or in the tail rotor. One main-rotor servoactuator was intact enough to allow bench testing. Disassembly of the two remaining main-rotor servos found no internal damage. The Takeaway All evidence indicates that the helicopter was airworthy up until the moment of upset. Although both pilots were highly experienced and very familiar with the local environment, they chose not to climb away from a ridgeline buffeted by stiff, perpendicular winds and the rotor currents they generated, despite seeing indications of sharp local downdrafts. Transport Canada recommends postponing mountain flights if the winds at the peaks are forecast to exceed 30 kt.; the FAA suggests a 25-kt. limit. The FAA also recommends pilots climb to at least 1,000 ft. above a ridge at least 3 mi. before reaching it. Not wanting to climb to, say, 4,000 ft. on a 21-nm flight is understandable, but greater separation from what the TSB characterized as the “complex terrain” of Howe Sound would likely have helped the pilots to avoid the worst of the resulting turbulence. The pilots’ confidence in the forecast of improving conditions may also have been misplaced. By 10 am, about 10 minutes after the accident, winds at Pam Rocks had increased to a base velocity of 36 kt., with gusts up to 52. Between 9 and 10 am, the wind at Vancouver International Airport had likewise increased, from 19 kt. with gusts to 26 to 26 kt. with peak gusts of 38, conditions unfriendly if not downright inhospitable. As severe as this accident was, it’s also worth noting that some things went right. The cargo line, hook, and nets were all secured in the cabin and remained stowed, but various small items were carried in an open milk crate lashed to the cabin floor. These became projectiles when the helicopter departed controlled flight. The TSB report draws attention to the fact that both pilots wore flight helmets of recent vintage that incurred significant damage from the impact of those objects, thereby protecting the pilots from severe head injuries and enabling them to evacuate quickly after the crash. The use of flight helmets and four-point restraints helped limit the severity of their injuries. Most crucial is the fact that despite the damage inflicted by the bumping episode, the main-rotor mast held together until the helicopter reached the ground. The FAA notes that “turbulence, especially severe downdrafts,” is a known cause of the low-G conditions in which two-bladed teetering rotors are susceptible to mast bumping. Fracture of the main-rotor mast, of course, is generally not survivable, so on that point these two aviators were fortunate indeed.
