ERA17FA190

The pilot's loss of helicopter control during a missed approach in instrument meteorological conditions due to spatial disorientation and the cumulative effects of task saturation.

The purpose of the flight was for the airline transport pilot of the helicopter to practice solo instrument approaches in instrument meteorological conditions (IMC). The pilot received adequate preflight weather briefings using company-approved weather sources, including one 35 minutes before departure. The terminal area forecast published earlier that morning and valid for the pilot's anticipated time of arrival at the destination indicated that the visibility would be 6 statute miles with an overcast ceiling at 1,200 ft agl; though the most recent surface observation report contradicted the forecast, indicating that the visibility was 4 statute miles in rain and the overcast ceiling was at 500 ft. The pilot subsequently submitted a flight request form to his company, which documented the weather products he reviewed before the flight and indicated that he was aware of the reported and the forecast weather conditions for the route before departure. The company's operation control center approved and released the helicopter for the flight. A review of weather radar and surface weather observation reports current at the time of the departure revealed that the helicopter entered and remained in IMC as it continued to the destination airport. A review of radar data and air traffic control (ATC) communications revealed that controllers provided radar vectors to the pilot for an instrument landing system (ILS) approach. The helicopter intercepted the localizer course about 1 nautical mile (nm) outside the approach gate. The controller then cleared the pilot for the approach with a restriction to maintain an altitude at or above 2,000 ft mean sea level (msl), which was both the assigned altitude and the intermediate altitude for the approach, until established on the approach and to contact the control tower at the destination airport. The pilot acknowledged the clearance and contacted the tower controller shortly thereafter. After checking in with the tower controller; the helicopter maintained 2,000 ft msl as it continued through the glideslope and crossed over the locator outer marker, which had a published crossing altitude of 1,842 ft msl. As the helicopter reached a point about 3 nm inside the outer marker, while flying at an altitude about 2,000 ft msl, the pilot declared a missed approach, telling the controller that he had received "some bad vectors at the very end" and that he wanted to "just line up and come back around again." The controller advised the pilot to fly the published missed approach procedure (a straight-ahead climb to 900 ft msl and then a left climbing turn toward the next navigational fix, at an altitude 2,000 ft msl). The helicopter then climbed straight ahead to an altitude of 2,525 ft msl in 9 seconds, before it turned right and started descending rapidly. The helicopter's calculated rate of climb before it began to descend was about 3,000 ft/min, while it's calculated groundspeed was about 120 knots. This climb rate and speed were not consistent with the pilot using the helicopter's automatic flight control system go-around mode because they were well above the climb rate and groundspeed that the "go around" mode would have maintained. Radar contact was lost as the helicopter descended through 1,625 ft msl, and the calculated descent rate between the helicopter's final two radar-recorded positions was more than 7,000 ft/min. No further communications were received from the pilot. One witness reported seeing the helicopter "spinning down…out of the clouds in an upside-down nose dive." Another witness reported that the helicopter descended "like a rocket" and that he did not observe any smoke or fire before the helicopter impacted the ground. The helicopter came to rest in a ditch, fragmented and mostly consumed by postimpact fire, about 3,200 ft before the runway threshold. All the helicopter's major components were located in the wreckage area. Examination of the helicopter revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The weather conditions recorded at the destination airport showed that IMC existed with easterly surface winds, visibility 2 1/2 statute miles in mist, an overcast ceiling at 500 ft agl, and temperature and dew point of 16°C. An AIRMET was current for low-level wind shear and turbulence for the region at the time of the accident, and high resolution rapid refresh model sounding data from around the time of the accident indicated that there was a possibility of turbulence. However, there was no verification of any significant wind shear or turbulence in any PIREPs, and the pilot did not report turbulence to air traffic control. Therefore, it could not be determined if turbulence contributed to the accident. Although the radar vectors provided by the controller during the approach were contrary to the FAA's guidance to air traffic controllers, which required aircraft to be vectored to intercept an ILS localizer course 2 nm outside the approach gate given the weather conditions that prevailed at that time, radar data confirmed that the helicopter successfully tracked inbound toward the airport on the localizer course. Although the radar vectors did not directly contribute to the accident, they likely increased the pilot's task load during the accident sequence. Several factors indicated that the pilot was task-saturated when the accident sequence occurred: he was performing an instrument approach that he had not previously performed; he was provided radar vectors close to the approach gate, which accelerated the timeline of the approach procedure; and he was likely already planning the return flight to the departure airport, which he previously indicated to the controller that he would conduct following the approach. That the pilot did not descend the helicopter after intercepting the glideslope or passing the final approach fix and did not fly the published missed approach procedure are indicative that he had likely become task-saturated during the final moments of the flight. Nontime-correlated but sequentially recorded data recovered from the helicopter's warning unit revealed that, at some time during the accident flight, the greater-than-106% rotor rpm warning indicator illuminated multiple times, then the greater-than-112% rotor rpm warning illuminated. The rotor rpm warnings cycled between greater than 106% and 112% and less than 95% multiple times. Given that no discrepancies wiht the helicopter's engines or rotor system were discovered during the postaccident examination, it is likely that these rapid, dramatic changes in rotor rpm annunciated and recorded by the warning unit were the result of the pilot's control inputs as he became task-saturated and began to experience the effects of spatial disorientation. The helicopter's subsequent rapid climb, right turn contrary to the published missed approach instructions, and its near-vertical descent are consistent with the pilot's loss of helicopter control due to spatial disorientation.

HISTORY OF FLIGHT On May 25, 2017, at 1153 eastern daylight time, a Eurocopter Deutschland GMBH EC 135 P2 helicopter, N62UP, was destroyed when it impacted terrain near New Castle, Delaware. The airline transport pilot was fatally injured. The helicopter was registered to the University of Pennsylvania and was being operated by Metro Aviation, Inc., as a Title 14 Code of Federal Regulations Part 91 personal flight. Instrument meteorological conditions (IMC) prevailed at the accident site about the time of the accident, and an instrument flight rules (IFR) flight plan had been filed for the flight. The local flight originated from Atlantic City International Airport (ACY), Atlantic City, New Jersey, at 1117. According to a representative of Metro Aviation, a helicopter air ambulance operator, the purpose of the flight was for the pilot to practice instrument approaches at New Castle Airport (ILG), Wilmington, Delaware, pick up a clearance in flight, and then return to ACY. The pilot obtained weather briefings via the Foreflight application at 1026 and 1042. The briefings included weather observations, forecasts, and NOTAMs for the departure, destination, and selected en route stations; PIREPs (pilot reports); and in-flight weather advisories for the planned flight. At 1043, the pilot submitted a flight request form to the company, which documented the weather products he reviewed before the flight and indicated that he was aware of the reported and forecast weather conditions for the route before departure. After reviewing the request, weather, and risk assessment, the company's operation control center approved and released the helicopter for the flight five minutes after the request was submitted. In addition, the pilot performed and signed off the preflight inspection of the helicopter the morning of the accident. A review of radar data and air traffic control (ATC) communications provided by the Federal Aviation Administration (FAA) revealed that after departing from ACY, the flight proceeded uneventfully and at 1150, an ILG tower controller cleared the pilot for the ILS RWY 1 approach (see figure 1, which shows an overhead view of the helicopter's radar ground track overlaid on the ILS RWY 1 instrument approach procedure plan view). The radar track showed that the helicopter was established on the final approach course about 2,000 ft mean sea level (msl), which was both the assigned altitude and the intermediate altitude for the approach. The helicopter maintained 2,000 ft msl as it continued through the glideslope and crossed over the locator outer marker (HADIN). The published crossing altitude for HADIN while established on the glideslope was 1,842 ft. Figure 1. Overhead view of helicopter's radar ground track (red) overlaid onto the ILS Rwy 1 instrument approach procedure plan view. The helicopter continued on course toward the runway; when it was about 3 miles, and about 2 minutes and 15 seconds beyond HADIN and still at an altitude of 2,000 ft msl, the pilot declared a missed approach. The controller advised the pilot to fly the published missed approach procedure. (The published procedure was a straight ahead climb to 900 ft, then left climbing turn to 2,000 ft to a heading of 220° to the ELUDE fix). Following the instruction, the helicopter climbed on course to 2,525 ft msl before it turned right and started a descent to 2,225 ft msl 4 seconds later. Subsequently, radar contact was lost when the helicopter was at 1,625 ft msl, and no additional communications were received from the pilot. One witness reported seeing the helicopter for about two seconds "spinning down…out of the clouds in an upside-down nose dive." Another witness reported that the helicopter descended "like a rocket" and that he did not observe any smoke or fire before the helicopter impacted the ground. PERSONNEL INFORMATION The pilot held an airline transport pilot certificate with a rotorcraft-helicopter rating. Additionally, he held a flight instructor certificate with helicopter and instrument helicopter ratings and a private pilot certificate with airplane single-engine land and instrument airplane ratings. The pilot's most recent FAA second-class medical certificate was issued on October 20, 2016. At that time, he reported 4,200 hours of total flight experience, 100 hours of which were in the previous 6 months. According to Metro Aviation's duty log for the pilot, he had accumulated 827.0 hours of flight experience with the company since he was hired in June 2013, 21.9 hours of which were in IMC and 33.2 hours of which were simulated instrument time. Since January 1, 2016, he had completed 18 precision instrument approaches and 21 non-precision instrument approaches. The duty log indicated that, from January 2016 through the accident date, the pilot had only flown to ILG for the company once, on March 12, 2017, on a day, visual flight rules flight. The pilot's most recent instrument proficiency program check flight was on April 9, 2017. During that flight, the pilot practiced several types of instrument approaches, including an ILS approach and a missed approach. AIRCRAFT INFORMATION The light helicopter was manufactured in 2006 and was configured with the pilot's seat on the right side. It was equipped with two Pratt & Whitney Canada PW206B2 engines. The helicopter was equipped with a four-blade, rigid hingeless, bearingless main rotor system. In addition, it had a fenestron-type antitorque system, which is comprised of a ten-blade fan housed in the vertical fin. The helicopter was also equipped with an Automatic Flight Control System (AFCS), three-axis autopilot. According to the helicopter flight manual, the AFCS had the ability to perform several different types of instrument approaches such as localizer approaches and ILS approaches (which used localizer mode with the glide slope mode), in addition it had a "Go around (GA) mode," which could be used in the event of a missed approach. When using the autopilot during an ILS approach, the AFCS would capture and fly the localizer first, and then capture the glideslope and command the helicopter to track the glideslope beam. The glideslope mode captured when the glideslope deviation was inside the -0.2/+0.5 dot range. In order to use the autopilot for an ILS approach the approach and the glide slope modes needed to be engaged separately. In the GA mode, the helicopter would acquire and hold a vertical speed of 1000 ft/min or 75 knots indicated airspeed. According to the helicopter's maintenance logbook, the most recent approved aircraft inspection program 100-hour inspection was conducted on April 25, 2017, at an airframe total time of 5,152.1 hours. Before the accident flight, the helicopter's airframe total time was 5,163.1 hours and the left and right engines total operating times were 5,168.9, and 5,155.7 hours, respectively. METEOROLOGICAL INFORMATION The 1036 weather observation from ILG, which was the prevailing conditions when the pilot was performing his preflight weather planning, reported wind from 070° at 13 knots, visibility 4 miles in light rain and mist, overcast clouds at 500 ft above ground level, temperature 14° C, dew point 14° C, and an altimeter setting of 29.52 inches of mercury. The 1151 weather observation from ILG reported wind from 050° at 7 knots, visibility 2 1/2 miles in mist, overcast clouds at 500 ft above ground level, temperature 16° C, dew point 16°C, and an altimeter setting of 29.53 inches of mercury. Helicopter Emergency Medical Services (HEMS) Weather Tool images depicting the route between ACY and ILG, at 1000, 1030, 1100, 1130, and 1200, all indicated that IMC to "low" IMC prevailed in the area. Terminal Forecast The 0800 forecast for ILG predicted wind from 080° at 12 knots, gusting to 20 knots, visibility 4 miles in light rain showers and mist, ceiling overcast at 800 ft. The forecasted weather at