Aviation Accident Summaries

Aviation Accident Summary ERA09IA186

Gainesville, FL, USA

Aircraft #1

N911UF

AGUSTA A109E

Analysis

During a nighttime helicopter patient transfer, while the helicopter was descending through 800 feet at 145 knots, a duck impacted the windshield. The windshield shattered, and a number of switches and circuit breakers on the pilot’s overhead panel were broken, while others were turned off. The engine throttles were not affected. The pilot maintained control of the helicopter and landed it without further incident. Analysis of windshield fracture surfaces revealed that they were typical of overstress with bending deformations. There was no forward shielding of the overhead panel switches and throttles.

Factual Information

On March 5, 2009, about 2010 eastern standard time, an Agusta A109E, N911UF, operated by Air Methods Corporation, as a ShandsCair medical evacuation flight, incurred minor damage from a bird strike while approaching Gainesville, Florida. The certificated airline transport pilot sustained minor injuries, while the flight nurse, flight paramedic, and trauma patient were not injured. Night visual meteorological conditions prevailed, and no flight plan had been filed for the flight between an automobile accident site in Trenton, Florida, and Shands Helistop (FA12), Gainesville, Florida. The air medical evacuation flight was conducted under the provisions of 14 Code of Federal Regulations Part 135. According to the pilot, the incident occurred when the helicopter was inbound to the hospital, about “3 minutes” from the hospital's rooftop helipad. The helicopter was descending at 145 knots through 800 feet, when the windshield “exploded.” The pilot was pelted with plexiglass and other debris. The master caution warning light started flashing, but the pilot had difficulty reading the caution warning lights as the left lens to his eyeglasses was missing. The pilot was eventually able to determine that SAS number 1 had been disengaged, and after resetting the switches, the master caution light extinguished. The pilot also noted that the instrument panel lights were off on the pilot’s side, so he reached up to the overhead panel and turned the lights back on. He then noticed that several circuit breakers and switches were broken off, and that several other switches had been moved aft, to the "off" position. The entire overhead panel was covered in blood. The pilot also determined that despite the wind noise, the helicopter was still operating normally, and he subsequently landed it at its home base, a ground helipad, without further incident. The patient was then transferred 1 mile to the hospital's emergency room by ambulance. Postflight examination of the helicopter revealed that a 2- to 3-pound duck impacted the helicopter, and came to rest inside the cabin, at the feet of one of the medical crewmembers. The impact broke off the landing light switch and turned off the navigation lights and the anti-collision light. The pilot’s instrument panel lights rheostat was rotated to the point of turning off the lights, and circuit breakers for the number 2 engine starter/generator were broken off, although the circuits remained energized. The circuit breaker for the “Outer Link” satellite tracking system was deactivated, which resulted in the ShandsCair communication center’s loss of flight tracking at 2008. Blood was also found on one of the main rotor blades. The pilot further noted that aside from electrical control switches, the power control levers were also located on the overhead panel, and that if they had moved aft, there would have been a reduction of engine power. A photograph of the overhead panel revealed that there was no forward shielding of the switches and throttles. Shards from the shattered windshield were forwarded to the Safety Board for further examination. Plastic windshield fractures were found to be “typical of brittle overstress under primarily bending deformation.” Additional bird strike information can be found at the Federal Aviation Administration (FAA) Wildlife Mitigation web page, at: http://wildlife-mitigation.tc.faa.gov/public_html/index.html

Probable Cause and Findings

An inadvertent in-flight collision with a duck.

 

Source: NTSB Aviation Accident Database

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